Hacker News new | past | comments | ask | show | jobs | submit login

What does the idle power draw look like? I've always been super disappointed at the power draw of maker MCUs; just keeping the regulator on 24/7 depletes a moderately-sized battery in a matter of days.

It would be nice if they put something like a TPL5111 on board, which is an ultra low power device that can turn on at a set time interval, and then turn off on demand. So it will pull up the "enable" pin on your regulator, your microcontroller will boot, your program updates the display, and then you tell the TPL5111 to turn off, and you draw basically no power until the next refresh cycle. I actually use a RP2040 with one of these to drive an e-ink display that measures the humidity in my 3D printer filament dry box. It wakes up every couple hours to update the humidity (it doesn't change much), and I've been powering it from a 400mAh Lipo battery for several months that way. To me it was groundbreaking to bite the bullet and add another device to conserve power, the results are excellent. Would love to see a provision for one built into the next version. (And hey, dump a BME280 on there and I can replace my entire hacked-together device with one circuit board and a battery ;)

(Oh, and for people asking why I built my own humidity meter using complicated electronics and a computer program instead of a $2 jobbie powered from a coin cell that you can buy on Amazon, it's because I wanted to be pretty accurate with the measurements. 10% humidity is different than 9% humidity in this case. As for why an e-ink display instead of an ESP32 that writes the value to some database server and I get a text message when I need to recharge the dehumidifier... it's because I didn't feel like writing that particular computer program at the time. Wifi connection errors. Authentication tokens. I'll just look at the display when I walk past ;)




You can shut down power almost entirely with circuitry to trigger a wake from sleep when pressing a button. It's no RTC but a compromise we made to hit the price point and allow for a very long battery life!


OK, makes sense. I looked at the schematic and saw a lot tied to the regulator enable pin, and that compromise sounds great for the badge use case.


After a quick look at the schematic it appears the current in the off state is somewhere around 3uA.


Customized board ESP32 could have deep sleep mode with wifi, I couldn't see the reason of choosing rp2040 not ESP32. Prob just due to rp2040 is cooler than ESP32?>


Because it's designed by a Pi specialist retailer

> In honour of Raspberry Pi's 10th birthday

And possibly also because rp2040 is readily available these days. Are esp32 stocks - and therefore prices - currently in the same good shape (honest question)?


ESP32 has been pretty good whenever I have checked them. An right now 10k stock on Digikey for esp32-wrover, at standard prices, and manufacturer lead times still listed as 8 weeks.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: