*====================================================* *If you got that far in the video: NO BOARDS remaining! ALL GONE* *====================================================*

A couple of months ago I created an STM32F103 design and inadvertently put a GD32 in it. Inadvertently because these were counterfeit chips: the GD32 markings had been removed and replaced with STM32 markings. After writing my firmware to the GD32, it only half worked. Nothing on the I2C bus was responding. I wrote a test application that toggled the I2C wires as GPIO pins to be sure I didn't have the lines bridged or something. In GPIO mode, the I2C lines toggled fine but they did nothing in I2C mode. After acquiring genuine STM32 parts, everything on the board worked. I never solved the problem, but it did drive home one very important point: the GD32 is not a drop-in replacement for the STM32! I guess the moral here is: don't declare victory if you've only tested GPIO. It's comparatively easy to get GPIO right, but I2C, SPI, ADC and DMA state machines are much more complex. The I2C incompatibility of the GD32 is well known and it was a mention of this incompatibility problem on the stm32duino forums that led me to suspect, test, and verify that my first STM32s were in fact counterfeit remarked GD32s.

Maybe this has been said but I don't want to wade through 80 comments to find out. I have used both paste and drag soldering on fine pitched chips. With the solder paste a good deal of the paste is flux. When heated the little metal balls melt and migrate to the solder pads with none remaining outside the pads. This works even without a solder mask. Your friend capillary action at work. Should be UKposts content on drag soldering. Good video

Damn. I have not the time to watch your videos now. But I save them all in my list "autumn projects". Keep 'em coming. Thanks.

Awesome video yet again Ralph! I'll be procuring me some of those GD clones for sure.

Cheers Ralph, all great info.

Your last two videos have encouraged me to dig our a number of Blue Pill boards I have stored away. It would appear that since V1.6 of STM32 Cores was released that all uploads require the installation of STM32CubeMX this provides the command line API to allow STLink and Serial uploads to the board. Another nice feature is the compiler setting to use USB Serial as the default UART thereby freeing up the serial GPIO pins for other uses, I've had no luck installing the Bootloader on these boards so I'm using STLink. Keep up the great work, I look forward to your video every Friday as they are always interesting and informative.

For the chip. Solder just one corner pin first, get it aligned , do not put solder on pads etc. then solder opposite corner, do not worry about extra solder or joins between other pins. use your iron on an angle put flux on the pins first, then flow a molten ball of solder down the row of pins. then to clean up use 2mm solder wick on the END of the pins to suck the extra solder down and away, moving the solder wick and iron together, no pressure on the pins. for the 0603 components use flux to stick them to the pads, then use a trimmed ice cream stick leaning on the component with a small weight, (I use the solder roll) to hold it then touch a very thin solder (I use 0.56mm) to the end of the component touch the pad and solder with the iron remove the solder and approach the component, and it should flow up the end. slide the iron back away from the component and pad. Takes practice. Other wise, use the flux again to hold the chips, and put a tiny bit of solder paste on the pad with a syringe, and use a hot air pencil to flow it. Either way clean up the flux with IPA after.

I have sometimes been successful with the drag soldering technique, where the tip is loaded up with solder, and dragged across the pins. You need a decent soldering iron and a good amount of flux, but when it works, it's great. You can also do reflow soldering using the hot air gun and just putting down a line of solder paste across all the pads. The solder only sticks to the pads and the legs of the chip, and surface tension tends to pull it all into place. You do have to do a visual inspection, or check with a multimeter, but generally a slight touch with a soldering iron will get rid of any short circuits.

Well presented and engaging, thank you. :3

Great video as usual. Keep up the good work. I don't think I could solder that small. Age gets us all

It's time for a following-up. There are a lot of new stm32F103s clones, some have more flash and RAM and much higher clocks.

*Thumbs up* I got GD32 chips from LCSC as well. First idea was to design a custom board with different kind of external components for testing I2C, SPI and other things. After couple of design ideas, I decided to take advantage of the breadboard friendly BluePills that I already have. I also replaced chip on board with the GD32. There are two ways I like to use when soldering fine pitched SMD ICs. I think first one is easier, if one doesn't have good eye sight or hands are shaky. 1) Add thin line of solder paste (Doesn't cost much on eBay/Aliexpress, if you don't already have it) across the pads, place the IC on board and apply heat with reflow station / adjustable hot air gun. Alignment isn't too important, surface tension will take care of small errors in alignment. or 2) Add flux to the pads, place the IC on board and tack it in place with tinned soldering iron. Go on and touch each leg with soldering iron (dragging, or "poking" one-by-one, which ever feels more natural), adding flux and solder when needed. Solder bridges can be cleaned by adding flux and touching them with clean soldering iron. Larger bridges can be cleaned with solder wick. And of course there are reflow ovens and other ways to do it, but those two are simple methods for simple tasks of soldering one IC.

Hey Ralph, fun and interesting comparison. I guess the primes/clock is roughly the same for GD32 and STM32, with the ST one having a bit of an upperhand. Some suggestions: 1) overclock the STM32, you can make it work at 108Mhz by modifying the PLL clock multiplier which is usually at x9 for 72Mhz but can be set higher. 2) check out those ST-Link V2 programmers, they are really cheap and use a STM32F1xx chip inside and if you open them they include headers so they be reprogramed like any other STM32 Thanks for the great content.

Yet another great video, thank you. For soldering the chips, definitely look at drag soldering (search UKposts for David Watts and scroll back a year or two and he has a great video doing it). Alternatively spread some paste across the pads, drop the chip on and heat with your air gun. So long as there is solder mask between the pads then surface tension will pull the solder to just the pads and pull the chip into place. If you get the amount of paste correct there will be no shorts as the solder mask repels the molten solder. Alternatively take a look at Unexpected Maker's channel and search for the video on his reflow master. More expensive though as that requires a toaster oven.

Hey Ralph! The "O3" compiler flag is activating all optimizations for speed, e.g. that does stuff like unrolling loops and the like, to gain the most execution performance, even when this takes up significantly more program space in the outcome. The more moderate in regards to program space is "O1", which tries to minimize code size if possible. And "O2" is somewhere in the middle, where some optimizations can cause some increase in code size. --- Best wishes from Berlin!

You may find this interesting Ralph. I have this STM32_Nucleo F0 board and I have played around with it in the past. I used the STM development software Cube and HAL to program the board because at that time the only Arduino core (wrapper) was for the 103 chip. That Arduino core is known as STM32_Arduino core or "Rogers core". Your last video made me pull out the board and program using the Arduino extensions through Platformio. VSC/Platformio IDE uses STM32duino core. This core supports many more boards Nucleo, disconvery, and chips, F0, F1,F2,F3,F4,F7. The STM32duino was written by ST themselves and is now considered the "official" Arduino core. The official core uses HAL where as "Rogers" core (STM32_Arduino core) uses the Standard Peripheral library. I think in this video you are using the Rogers core which many people still use. No need to use Platformio as the STM32duino core can be installed into the arduino ide . The ST official core became available in May 2017. ST supports the core with a ST employee on Rogers STMduino forum, crazy days !

I'm getting the age related vision problems too. For small work like that, I use the +3.5 magnification reading glasses that my local dollar store sells. They work great.

Great video, Ralph. Just one thing though - the number of primes per 30 sec is not a good indicator of speed, because the amount of time required to check if number N is prime is proportional to N^2. I think it would be better to fix the amount of work the CPU should do (let's say, calculate the first 1000 primes) and measure the time it takes to do it.

Thanks Ralph and LCSC. I didn't know the GD32 was actually a viable alternative. I looked into that chip around a year or two ago, found some forum posts that said it had bootloader issues, and didn't go any further with it. Now I know better, thanks. While I'm no expert on soldering, I've soldered chips on several boards with TTSOP, and TQFP 32/64/100 chips. If I have a board I am going to etch several of, I make a solder mask and a stencil first. I make my stencils with a similar process to my single sided boards with a photoresist on a piece of aluminum cut from a soda can. I only use solder paste if I have a stencil. That will change soon though. I will be forced to use paste with a project that has my first QFN footprints/chips in the near future. I haven't had much luck using hot air with larger SMD chips or anything without a stencil. I actually use my main, large chisel tip on my iron. First a bit of background. I have the old RadioShack "Digital Soldering Station" still. It's an Atten 60w station that was just rebranded for R.S. It is a Hakko 900 series-ish station with a 2 wire element instead of a Hakko 900 type 4 wire, but it has an identical handle and form factor otherwise. The important bit is that it is a true 60w and uses Hakko 900 series tips. My main tip is a genuine Hakko 900M-T-3.2D. I got a bunch of them on eBay second hand NOS in the original individually sealed Hakko packaging. That tip makes a big difference for me in a lot of different circumstances like this. I have tried several dozen tips, many were clones and the last dozen or so have been genuine Hakko's. I have several fine pointed tips that I will use if I am forced to, but I use my main chisel tip 95+% of the time. This tip holds an enormous amount of thermal energy compared to all the other tips I've tried. I usually set it to 575F (302C) as my general setting. This is hot enough to work on almost anything. It is also hot enough that intentionally bridging standard 0.1in pins using good (MG Chemicals No Clean leaded 0.8mm) solder is nearly impossible. My low temperature setting with this iron for stuff like cheap perfboards and bridging pins is 505-515F (263-268C). All of my other tips I use regularly require settings that are around +100F (+50C) higher than this tip to achieve the same results. I credit this tip's thermal mass as the biggest contributing factor when it comes to soldering fine pitch SMD stuff. I also use a block of Sal Ammoniac. That's the traditional name for a block of ammonium chloride. This has traditionally been used as a soldering iron tip cleaner. It will remove any oxidation from a tip. I think of it like soap for a tip. If you rub the tip around on the block with a bit of solder, then clean off the junk with brass turnings and a wet sponge, when you put fresh solder on the tip it will be just like a brand new tip. This is also the condition when real Hakko tips do really well IMO. I always do a cleaning routine like this before soldering a large SMD chip. I start by applying a lot of Amtech 559 UV flux to the clean footprint. My rule for flux is: "Too much flux = I can't see the footprint any more. AKA There's no such thing as too much flux."

Hi. If you have problems in soldering these tiny IC's on a board (like me too), just let JLCPCB solder it for you. They have very good component prices too. Now I have no more fear in using SMD Components like 0402 capacitors or resistors in my designs.

Very informative video

Great video again. Pls ignore trolls.... Thank you for sharing.

Great video Ralph- Q: does the STM Maple Mini require toggling the small yellow bridge pins after programming like the Blue Pill does? I think moving that bridge each time would drive me crazy!

Your comment on soldering. I have those days too. I just can't solder at all. Especially SMD stuff. After burning myself twice I usually find something else to do that day and leave the soldering to when I remember how to. Other days the solder flows like a glove every time as soon as it's touched, nothing sticks to the iron and everything ends up straight!

Check out a program called Zadig. It allows you to specify which USB driver is loaded. An alternative would be ImpulseRC driver loader. The Naze (pronounce Nah-zeh in a Japanese manner ) bootloader is what was loaded onto early multicopter fight controllers. Windows has a nasty habit of overwriting the USB driver so if stuff suddenly stops working that may be the issue.

One time I was eating chocolate chip cookies in front of my PC, when I picked up and ate a very crunchy crumb. I'm pretty sure it was one of the SMD parts I was picking out previously, when going through a list of needed components for a PCB, but suddenly vanished out from the tweezers. But don't worry, the parts were conforming to RoHS, so should be fine ;) I do like the 0603 or even 0402 size, not necessarily when designing a circuit, but for bodges and repairs. They fit in between pins or almost anywhere on a PCB after scratching away the solder mask. And they work even better on one off projects that are quickly done on perfboard, instead of using "huge" THT components. I'm quite myopic (5 diopters), so I see squat in the distance without glasses, but it's very useful when doing closeup stuff. Over 40 now and definitely recognizing that I can't go as close with my glasses on anymore, but the myopia will stick (luckily?), so no reading glasses for me.

Hi Ralph, I think I'm about your age and I have the same kind of eyesight issues. I have a couple of suggestions. Drag soldering works surprisingly well. You need to use plenty of a quality flux. I use water soluble organic flux. It works well and cleans up beautifully with soap and water. I'm not sure when you made this video, but now you can have JLC PCB assemble your boards as well as fabricate them. I've also had success with solder paste and a toaster oven. Thanks for the video! Cheers!

Thank you very much sir!

Thanks for all the great videos Ralph! That prime number code is an offense to mathematics in particular and the universe in general though. :)

Thanks for the tip about the naze32 firmware, I spent a couple of hours trying different ways to upload over USB. It is possible that you may have restored my sanity.

The other parts being so close may make it hard to use a soldering iron but I'd try the "Flood and Suck" approach. Clean the board well, flux the pads, place the part and solder it with the iron, not worrying at all about the bridging, just get more than enough solder on the part. Then use solder removal braid and suck out all the solder from the pins you can. The bridges go away but the surface tension will leave enough solder between the pins and the pads so that you end up with a nice solder job. To be sure, after soldering, use a magnifier to inspect. I use a xacto knife under a magnifier to gently push each pin. If the pin moves, it's not soldered. Rinse and repeat.

if you dont have a stencil and solder paste, i just slightly tin the contacts on the board with regular soldering iron, then add flux and hot air the chip on works pretty well

I hear what you are saying about small components and being older. I would recommend a large illuminated magnifying glass. The board is likely to have lead free solder on it also using flux paste will help a lot.

I picked up one of those "blue pill's" about six years or so ago. The Ebay listing said it was a super fast arduino! Never have gotten the blasted thing to work. Yesterday I was cleaning in my old backroom shop, long abandoned in favor of my recliner, when I came upon it, in a little static proof envelope that I pushed it in after many disgusting attempts to make it work, so thought I would view some of your videos and see if I could get the damn thing to do something. Still haven't tried but it is laying next to me on my end table right now. As far as micro soldering, I have the perfect tool! My unaided vision is at 20/400 20/400 (my doc says it is much worse then that but that is the top of the chart) With glasses, I do have 20/20 in both eyes. So all I need to do is remove my glasses and add a bright light, and instant microscope so long as it is about 7 inches in front of my nose. For an iron, I picked up some curved needle type tips, I use the backside of the curve for most joints but for tiny SMD's the tip works good so long as I have a good hold with my curved tweezers. I built one of those little SMD wristwatches with the clear case and leather band that are being peddled on Ebay using that, all very tiny soldering some in very close proximity to some melt-able cables that hook the screen to the board. I was very surprised indeed when the blasted thing actually worked when I finished. It had a couple of chips like the one on that board. The way I got them to work was to flood them with solder, then use the iron to flick off till only the links remained. I didn't think it would work but saw someone on a video do that so figured it was worth the try.

Dragsolder the chip with enough flux works really great. Have to use a proper solderingtip though

I just got hold of an STM32F401CCU6 WeAct board. I ran the Primes test and it finds 88049 primes in 30s, which is impressive. Programming was straightforward and the USB bootloader worked first time. I think its work looking at both this board and the 100MHz STM32F411CEU6 WeAct board. Both of these boards have Floating point processors so that brings other performance enhancements over the STM32F103 blue pill boards

When surface soldering try putting a strip of paste right across all the pins (right angle to the pins). When you place the chip and hit it with heat the paste will melt and suck into place.

I got a blue pill about a week ago. I was trying to hook a literal USB to serial link into the uart for programming and of course that would not work. Then I tried to program it using a ttl serial converter today. It does not work for whatever reason, including me blowing the uarts. I soldered a 2K resistor I found on some scrap on. I finally decided I had to use tweezers while soldering to force it into place because you just can't to it with just your soldering iron. Very small stuff.

I have been meaning to ask you how you were getting along with the YOCTOSUN LED Light Hands Free Headband Illuminated Magnifier that you bought when starting to use SM components

Ralph take a look at the ADSM301 and the ADSM302 USB microscopes I got the ADSM301 about 6 months ago and I love it, it was around 150$ US, now looks like it's around 180$, for a 20$ or so more, the ADSM302. Before, I was using a magnifying lens and I would get headaches and my eyes would "wig out" :) for a few hours. These have excellent working height unlike the cheap 10-20$ USB microscopes. My next planned upgrade would be to mount it on a articulating stand so I can examine larger boards like PC motherboards and XBOX boards

Tell me, what kind of plate do u have ontop of the table? I mean the green plate with those squares. I didnt found any similar on ebay. nor on internet at all, may be because of wrong search-text.

Ralph ... I can TOTALLY relate to your eyesight/soldering etc. thing and everything else you're talking about. I'm 65 and can't see my hands in front of my face without one or another pairs of reading glasses. HOWEVER ... there is help. First ... Forget about USB microscopes for soldering. What you want (trust me) is an "Optical" stereoscopic microscope. I heard the part about 'you can't afford much', but honestly, these are a game changer, and they are a LOT less expensive than you might think. (USB microscopes are great for other things, but not for soldering.) I bought an Eakins 'trinocular' (the 'tri' means there is a 3rd tube for mounting a camera), but the 'binocular' is more than adequate if you just want help seeing small stuff while soldering. Get the 'lowest' magnification range, typically 3.5x-45x. (trust me, you don't need any more than this.) You can find more on their AliExpress site: www.aliexpress.com/store/836673?spm=a2g0o.detail.1000002.2.5aeb643f8U2BIV They have a billion different options on their site, and it can be confusing, but really everything comes down to a few options: 1) trinocular vs binocular, 2) high vs low magnification, 3) type of stand, and 4) which camera if you pick the trinocular option. Eakins is not unique, there are several other suppliers selling very similar equipment, for similar prices. Further, every month or two they have sales. ... Wait for the price drop. Why the pitch? Recently, I bought about 15,000 0402 resistors and capacitors from LCSC for a total of only a few dollars. Look for yourself; you can purchase 1000 resistors for as little as $0.38CDN/1000. I've never heard of anything SO CHEAP. 38 cents for 1000 of anything. I haven't done much with these yet but importantly, with my microscope, I don't have ANY PROBLEM at all soldering them. Did I mention ... my eyesight SUCKS, and is probably even worse than yours. And, soldering 0603 parts is literally ... EASY and routine. You didn't mention what kind of soldering iron/solder you are using. I have learned over the years that these make a world of difference. Some time ago, I bought a 'BAKON 950D' soldering iron. This is one of the 'new' type irons, which is VERY responsive to temperature changes. Unlike others however, this sells for about $50, and honestly it is ABSOLUTELY AMAZING! Again, there are other similar options. Solder is a whole other issue, but I use 37/63 lead based solder, 0.3-0.5mm. It is FAR easier to work with than lead-free solder. But if you think lead is a dirty word, then spend a LOT of money and get GOOD lead-free, otherwise you'll find soldering to be tedious and difficult. I have no commercial interest in supporting the above ... I've simply figured these things out from experience. I hope this helps.

Nice video, thank you

Hi Ralph, the green pill looks like a fun project... just wondering if you thought about hard wiring extra functionality to the board, like maybe a temp sensor, canbus chip or opto-isolated inputs?

Like others have said, I'm a fan of spreading some solder paste over the board and running over it with a soldering iron, effectively tinning the pads without putting solder everywhere. Then start in one corner and work your way around. Also, plenty of practice can be done on old or broken boards- why practice on good components 😀😀😀

Hey Ralph great video !! Where in the UK are you from ? Thanks for your channel !

That's CS32 from CKS... GD32 (F103) uses serial flash (like ESP32) to store program. That flash then copies itself at boot to SRAM (yes, it has more SRAM) which allows microcontroller to run at higher speeds with no waitstates (and elaborate accelerators). CS32 - I don't really know how they handle things. However ARM Cortex Core performance isn't actually the most important thing in microcontroller world. It's more interesting if GD32 and CS32 has at least similar ADC, Timers, GPIO, SPI, I2C, DMA performance.

I believe the right technique to solder chips like that is to use some of that jelly like flux that comes in a syringe, you tin your iron tip and drag the tip across the pins, the flux does it's magic and the solder just sticks to the pins/pads perfectly. Look at this video from Snazzy Labs where he's building a RPi Zero retro gaming handheld - in particular where he solders the ribbon cable for the screen. I also believe iFixit have done a series on micro soldering too.

Creality replaced the STM32F103RET6 with the GD32F303RET6 in the Ender 3 Pro. Is there a possibility of extracting the source code from the board? I am not knowledgeable about this topic. Anyway, I like the explanations in your video and the way you present yourself. Keep it up and who knows, maybe someone or I will find a way to figure this issue out.

For old eyes with up-close work, I bought a few "old man" reading glasses. They have several levels of magnification. I like the 2.0 versions.

hi Ralph, May I know does JCLPCB sells ready made PCB with G32F103C8T6 and its components soldered or any other sited has it ?

This clears a lot of confusion!! I'm trying to replace STM32F103CBT6 from one of our products due to chip shortages and price hikes. Since I'm getting the PCBs from JLC, I am looking for IC supplies from LCSC. Now, LCSC does have GD32 F 103CBT6 (Cortex M3) in stock right now, however, they have GD32 E 103CBT6 (Cortex M4) at a very good rate and in large quantity. Although I've ordered 10 pcs of E103 from LCSC so that I can discover myself, but I'm just dying to know these: 1. My board currently has an FT232 on board. Can GD32 E 103 be programmed through the HW bootloader on Serial1 ? 2. What config changes will I need to make in arduino in order to build? 3. What config changes will I need to make in arduino in order to Upload? 4. And the most important one. I use FT232 earlier and it gives me data rates up to 2Mbps. Which is very much required by my application. Can the USB be used to program in the bootloader and also simulate Serial-over-USB while in the application? Will it give me at least this much bandwidth? (Some forums claim that with some buffer upgradations, it should go as high as 8Mbps, is it true on the standard bluepill)?

hi there hay just wondering on avage what micro..... do you tend to use the most.. and one more i tend to used the uno in most in my projects (i just like it and pretty much has just the right amount of goodness for my projects) but what i do find a real pain in the ass is the fact that a lot of things tend to like 3.3 volts and not 5.0 volts if you hit this problem often what do you do to get around it i been using resistor as voltage dividers which seem to work ok but a real pain what's the answers lol.

You need reflow solder paste and a heat gun or toaster oven to solder down small parts like that. Once the solder melts, removing the part is very easy. Unpowered, electronics will tolerate heat of melted solder quite well. A small heat gun will cost $65 or so and is highly adjustable. Toaster ovens are very cheap, but they don't regulate tempurature as wel las a digital heat gun will. In either case you are applying heat to the board until the solder melts. Be careful to only touch the part you want to remove. You'll work inside the toaster oven so the board stays hot and remove or place the part. From that perspective the toaster oven is less convenient. The heat gun since you are in open air makes accessing the board easier, but you have to keep the heat on the board so it doesn't cool down. For reflow soldering a new blank board, put solder paste on all the connections. It's somewhat sticky so you can use the paste to stick down the SMD components to the correct positions. Heat the entire board in the toaster oven or play over it with the heat gun and the solder will melt and the parts will pop into place into the solder pools. It's much easier than trying to solder down tiny parts with your iron.

16:11 - the caps around the LDO are insane and will _cause_ usb problems. The USB specification lists 10uF as max (to lower the inrush current), so a 10uF and a 100nF on each side is just about right.

Have you used a mask and hot air gun or oven for SMD soldering? I use my hot air gun for lots of things, almost daily.

Update with riscv ch32v203c8t6 sir, so attracting

You can solder the LQFP just by putting a thin stripe of solder paste over the area the pins are to solder to. Hot air, wicking action combined with the solder mask will flow the solder to the pins and unless too much solder paste was use should not cause bridging. Use the desolder wick as indicated by David Westernall to clean up any bridging you see under microscopy. The hard part of this method is the chip will tend to float on the solder pads so you need to use some kind of a pick to position and then hold the chip down for a few seconds while the solder cools. Using a USB microscope to solder under does not work well. It is very difficult to position components and tools without stereo vision.

II gather your board is open source, you mentioned that LCPCB would supply boards fitted with components, any idea how much.

16:12 the guy changed the caps but never thouoght about adding a free wheel diode from out to in to protect the AMS1117 from the surge of current coming from the C6 discharging and going thru the reg everytime power is down, which will surely kill it in no time! The kind of thing I directly notice in a circuit and shun reading the rest.

Hey Ralph, Do you have fixed set of schematics for the GD board. I would like to put it together myself. Keep up the good work and pet the kitty for me

Hi Ralph, I thought you were going to put the GD32 onto a board to run it at 72Mhz rather than the 108Mhz in order to compare it with the STM32 (Blue Pill). Looking at your results, the increased speed of the GD32 looks to be purely down to the clock speed. Be goot to know how the GD32 performs your calculations when run at 72Mhz and could also be interesting if you can run the STM32 at 108Mhz! I was messing with the Blue Pill about 6 months ago and I also had real problems with the boot loader. I all came down to Windows 10. It was the driver rather than the loader that was the major problem. Days wasted trying to get it to work, when I did, it was no problem to program, but if I disconnected then reconnected, the driver wouldn't load. I had to re-boot Windows, then it would work again. I gave up eventually and just use the FTDI, it's just as easy anyway. Great informative video. Thanks. Martin

Umm in my ECE lab we used microscopes and regular old Weller irons, you start off by lin in ng up the chip, solder two corners, and then go arround getting the rest of the pins, to fix any bridges you just clean your iron tip and wick it off or over into the other pins

17:40 It is pretty simple to solder that stuff. Actually tehre are 2 good ways to do so. One is with your hot-air gun, apply the paste generously across the pins, do not worry about the single pins - just lay a small saussage across each side across the pins on the board, place the ic onto it, about where it would sit when soldered in correctly and heat the stuff up. The solder paste will draw to the contacts on the board on its own and with a tweezer you simply make sure the ic goes into the right position by rudly but gentil pushing around the ic to keep it in the position you want it to be afterwards. --- the second way is almost as simple. Take some solid solder and put the solder with some liquid flux onto the board, but without the ic first. When all connections have soem solder on them put the ic on top, heat the stuff up and use a tweezer to push the ic around to fit the right position when the whole stuff becomes liquid. --- In both ways the solder substance as well as the ic want to get into the right position on their own anyways, since there is a certain addiction caused by surface tension of the solder pads and the solder substance. Just make sure there is enough flux in play to lower the surface tension on the pads on the pcb. --- There is also a third method working without reflow oven, which relies on using superglue. You simply glue the ic in the corret position and then apply paste onto the pins like a saussage on each side of the ic and heat the thing up to make the paste become liquid and find it's place. Excess is removed afterwards with a desoldering braid (?) ... [Entlötlitze]. Do not worry to have pins soldered together at the first try ... it doesn't matter. Just solder the thingy into place and remove the excess afterwards...that will do the job. [edit] So do not worry to get the paste onto the pads. It doesn't matter at all, which also makes stenils pointless for small series done at home. If there is too much, get the excess off afterwards with a soldering iron / heat gun. Not worries about placing solder paste. It pointless fumbeling about effort at the end of the day ...

Could this be due to differences in the fuses on these chips ? Did you compare those?

What about the energyconsumption of the asian alternatives ?

Is GD32 programmable using ST-Link? I use Keil. If ST-Link can write a program there I can work in Keil.

I've bought 3 stm32 boards. On 2 of them, when I selects boot0 to 1, the blink sketch continues working and can't program via serial. I needed to buy an stlink.

I am still looking for a way to add the necesary files & packages to my IDE (without being connected to the internet!) to get it working. Just the way I do with my libraries which is very very easy. Is this possible? Just downloading some packages on a USB stick and copy them into some IDE folders. I still hope so.

Drag soldering, with 0.5mm soldering iron tip works fine down to 0.4 mm pitch chips. Micro scpe look at ADM503, good work clearance, many mscopes too close no space to work

21:47 you don't mention what solder you use for smd components. I assume you use solder paste.

Hi Ralph, A microscope is undoubtedly the best way to go, especially if you have tired eyes like I do but, they are tremendously helpful even for young eyes. Once you try one you will see for yourself that everyone that works with PCBs should have one. All of them have an independent adjustable focus on one of the eyepieces and in my opinion is a must! Just a note on magnification: You will likely never need magnification over 20X for PCBs! In fact, 7X to 10X seems to be the most common magnification range used for our application. 45X and 90X is just too much for what we do (in my experience). You mentioned in a response to a comment below that you would want to buy a Trinocular scope so you can use a video camera at the same time. "Be aware that Trinocular scopes only allow one of the eyepieces to be used while using the video camera" The only scope that allows you to use a video camera "While" using the scope with both eyepieces at the same time are "Simul Focal" stereo scopes! Simul Focal scopes aren't really more expensive, there are lots of deals on the net for Simul Focal scopes. Check out this video for an demo of using a Simul Focal scope as well how to successfully drag solder while using the scope and.....you'll see just how much flux he is using for the process. ukposts.info/have/v-deo/e4-WhaiZpqZeq2g.html You have received lots of great tips for soldering SMD components. It's obvious that you aren't willing to spend the money for the "Tools You Need" to do the job (which is kind of ironic since PCBWay is investing in you and your channel). You're going to have to bite the bullet at some point and "Invest" in the right tools for the job. I have found that one of these circuit board holders is also a must, this one allows for rotating the board so you can see the back of the board without having to remove it from the holder and it's pretty cheap (worth every penny IMHO). It helps a lot to be able to steady one hand with the other hand but to do that, the circuit board has to be held in place by something. This holder works very well under a microscope as well. www.amazon.com/Aven-17010-Adjustable-Circuit-Holder/dp/B00Q2TTQEE/ref=sr_1_3?keywords=PCB+holder&qid=1563118302&s=gateway&sr=8-3 Anyway, Best of luck to ya Ralph!

To place the chip on, solder with out a lot of care and then use solder rope on the top surface to remove excess solder.

The best way to solder these devices is by "drag soldering" where you wipe plenty of liquid flux over the pins and then drag a ball of solder on the soldering iron tip along all the pins. The key do success in this method of soldering is the use of liquid flux.

my standard st-link cannot connect to cs32f103 tell me what am I doing wrong?

Wait, I am confused. You run code which counts how many primes you have found, but finding the next prime should take more computational power than finding the previous one. Then how come the number of primes the ratio (primes stm32 found)/(primes arduino found) is much greater than (clock speed stm32)/(clock speed arduino)?

If you don't know how to solder SMD chips it doesn't hurt to watch a few tutorials. Btw. it's actually easy to solder with an iron with a chisel or bent tip just by holding the chip down with tweezers in the correct position, applying a Rossmann of flux(aka a lot), picking up some solder on the tip, and just dragging it over the pins, relying on the flux to keep the pins separate.

The CKS103f is not fully compatible with the STM32F103C8 Overclocking at 128 Mhz didn't work. The library for 7 segment display TM1637Display.h also didn't work. LCD library LiquidCrystal.h didn't work properly and displayed many incorrect characters. LiquidCrystal_I2C.h did work. I tested bij swapping a number of cks blue pills with stm blue pills in a soldered circuit.

Pre-solder the pads, run some flux over them, set the chip in place and apply heat. Looks like factory when you're finished.

even a cheap binocular microscope is far better than the best usb microscope. a good binocular microscope and an SMD soldering station (hot air) is the only way I've been able to get good results trying to solder fleas (0603s) to PCBs. It's amazing that you were able to solder those 0603s with a soldering iron. Great skill.

SMD soldering is not for my poor old eyes. Far easier to just order a blue pill. :D

Seems logical that the Naze32 bootloader would work well since the racing drone community has been using the STM32Fxxx CPU for quite some time now.

Hello Ralph, I hope you are doing well. STM chips are manufactured in many different countries like Korea, Malaysia, Philippines, Taiwan, and China. And I am thinking that GD, CKS, and CS are a few of these Chinese manufactures. So they don't have the need to clone them.

0603 are great :) 0402 is much more fun :)

Make sure that you wear breathing protection when soldering small SMD. 😎 I accidentally ordered metric 0402 resistors instead of imperial. Only 100, so it wasn't an expensive lesson.

Save up your coins and buy a true stereo microscope you will never look back. Get it with a .5x Barlow lens for better lens to board distance & easy access for soldering. For the small parts use .020" or .015" diameter solder (use lead based 63/37, none of this lead free crap) and a soldering iron with a fine conical .016" diameter tip. I use a Metcal iron but others irons with small tips should work fine.

Hi , I have Arduino Nano Stm32. Which has already program in it. I want to copy program from Arduino board.

I am impressed, soldering these small parts is not easy, I prefer 0805 parts. I have done some chips with about 0.6mm pitch, they are not easy (I cannot remove shorts with the soldering iron, but has to use solder wick). I often use a USB microscope to check stuff, but it is not easy to solder under. It looks like you are getting away with comparing the performance with the long data type, both mega and ESP32 use 32 bit values and I supposed the STM32 will also do that.

I know it's an old video, but if you haven't bought a microscope yet, I highly recommend. I recently bought one off Aliexpress with a 7" LCD and even though it's a cheap piece of crap which overstated it's magnification level by like 1195x and will probably burst into flames at any moment, it's a game changer compared to the magnifying glass on my "helping hands" and my eyesight isn't even that bad (yet).

why not change the Resistors and Caps to 0805? I always use 0805

The 330uF might be causing too high an inrush current - perhaps you had a lower ESR cap than R3bers?

BTW. PB0 and PB1 is shortcircuit ( solder bridge)

Hi Ralph. I am concerned about the interpretation of the performance data for benchmark (prime number finding) for 2 reason (see below), both reasons requiring more computations to find (on average) a larger .vs. smaller prime. This interpretation gives the same value (measure of computational effort) to finding small primes it gives to finding large primes. Thus over estimates the relative performance of the Arduino .vs. the other processors. I would have preferred your benchmark written as the time required to find all prime numbers between (for example) 2 - 1000000. In this way each processor is doing the same calculations and the time to execute is measured. Please Note: The error of relative performance is on the order of maybe 20%, not orders of magnitude. - - - - - - - - - - - - - - - - - - - - - - - - - below - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - The first issue is that the concentration of prime numbers is greater in the region of small numbers. The second reason is the inner loop executes more times (on average) to test if that number is prime as the number being tested gets larger . ( upper = sqrt(num); )

Couldnt the esp32 be twice as fast. It is a dual core?

18:00 Lots of Flux (like flooded with paste flux) then it is super easy since the flux will help prevent the pins from bridging. (Louis Rossman has a channel on Apple board level repairs, it is awesome). Here's an older vid where he does a QFN chip smaller than what ours ukposts.info/have/v-deo/paJiiYyHqnupynk.html

Hi, I don't go below 0805 either I think that's it at 53 without any expensive gear! as for the chips I thought the same way and now I'm playing with a dirt cheap (£6.70) hot plate, all I have to do is get a kindly Arduino to automate it and bingo, Roberts ya relative!, seriously look up "hot plate reflow" see what ya think, I mean there are folks getting good results using an upturned Iron!

You tack one or two pins and flood solder the rest. Then use solder wick to take off the excess. Watch Dave EEVblog

Does st link v2 work with alternatives ?

according to my eyesight you have shorted B0 to B1. (around 20.27)