In last week's EYE on NPI we used a platinum temperature sensor to perfectly cook a turkey for Thanksgiving. Having eaten the whooole thing (with stuffing, potatoes, cranberry sauce and gravy), we want to settle down for a nice deep sleep. And speaking of deep sleep, this week's EYE on NPI is all about that sleep with the brand new Power Profiler Kit II (www.digikey.com/en/products/d...) from Nordic. It's hot out of the oven, just like that apple pie, and ready to help you with measuring power usage with any setup or chipset.
We're always psyched to see companies release tools they use during their own development and tech support (www.nordicsemi.com/Software-a...) - clearly this is a design that Nordic customers will love - if you've got a Nordic wireless chip in your design, it's likely battery powered, and you're gonna want to get as much life and range out of that battery as you can. Nothing beats a good power monitor, but ones with good dynamic range, from uA to 1A can be really expensive - like on the order of $800! This one is 1/10th the price!
We tried it out to compare it against our existing power meter and for our purposes it does a great job. Software install was easy and the software is pretty straight forward. The device appears as a serial port, once connected you can either use it as an ammeter (e.g. pass through mode) where power is supplied by something else like a battery pack or onboard power supply. Or you can use it as a power source, with adjustable voltage output from 0.8v to 5V - handy when you want to simulate, say, two NiMH or one LiPoly or a lithium coin cell - all of which are different voltages. I connected up a JST 2 pin wire (www.adafruit.com/product/261) to have it simulate a Lipoly battery.
Then you simply click "start sampling" to start capturing data. I tested it with a WiFi board to get a wide range of samples, from 800mA peak when wifi starts up, to 250uA during deep sleep. I liked that the cursor can be used to pinpoint current draw. One thing to watch for is the 'bottom' of the Y axis isn't necessarily 0 uA, which can be a little confusing when the graph seems like its really noisy but its just that it's really zoomed in!
This tool is really essential for anyone working with circuits - you can't use a multimeter to measure these dynamic currents - and historically these kinds of tools were beyond a maker budget. This one is a strong recommendation for a stocking stuffer, and with Digi-Key's #digiwish give-away ( / digiwish ) happening this month, it's the perfect thing to wish for! You can also pick up the Power Profiler Kit II (www.digikey.com/short/zv99qh) tonight, to get profiling ASAP. We already grabbed two for our own use!
Digi-Key short link: www.digikey.com/short/zv99qh