3 ms·

ESP32 development boards are also very impressive. And the prices are dropping every month. Can't wait to see that ecosystem evolve.

duskwuff 9y ago
Same goes for STM32 (ARM Cortex-M) hardware. Actually, the prices have already basically hit rock bottom. :) You can get a STM32F103C8T6 (72 MHz, 20 KB RAM / 64 KB flash) on a development board for under $5, and a programmer/debugger for about the same price.
- pjmlp 9y ago
  ESP32 advantage is having 512 KB, back to the PC1512 days, just being multi-core and having network access. :)
pjmlp 9y ago
I don't have any use for them, already enough side projects as it is, but the technical specifications of ESP32 are great. It is like having a PC1512 that fits on the pocket, there are already lots of programming languages that would fit on it.
fest 9y ago
And Espressif got their act together this time and are working on a good and open-source SDK (ESP-IDF). I just tried it out this week to make battery powered wireless temperature and humidity sensors. Sleep current for the whole system is not that great (~80uA of which 40-50 are used by ESP32 module). However, the simplicity and ease of use outweigh having to charge the battery every 3 months (3Ah li-ion cell).
- MrBuddyCasino 9y ago
  30-40uA with only the ULP running?
  - fest 9y ago
    Now that you're asking- I don't really have an answer what exactly remains powered on. I have seen reports of people achieving sub-10uA sleep currents, so my result could be improved by a factor of 2 (LDO I put on board has Iq of ~40uA). I haven't looked really deep at what power modes are available for each power/clock domain- at the moment I just have the ESP waking up from RTC timer every 15 minutes and it can also be woken up manually with GPIO. It's entirely possible that I have left some peripherals at non-optimal state.
    - MrBuddyCasino 9y ago
      I see. I haven't explored the low-power states yet, the datasheet says 5µA is possible using hibernation and timer-controlled periodic wakeup. Was curious if those numbers are achievable.
      - michaelt 9y ago
        On the ESP8266 I was able to get down to 16.3 µA deep sleep current. A lot of easy-to-use modules come with a USB-serial converter and a 5v-to-3.3v converter. These will draw a few microamps even when there's no USB connected - and depending on the precise hardware, some will draw far more than that. You should plan on buying a few different modules and de-soldering a few components if you want to achieve the absolute minimum current consumption :)

duskwuff 9y ago

Same goes for STM32 (ARM Cortex-M) hardware. Actually, the prices have already basically hit rock bottom. :) You can get a STM32F103C8T6 (72 MHz, 20 KB RAM / 64 KB flash) on a development board for under $5, and a programmer/debugger for about the same price.

pjmlp 9y ago
ESP32 advantage is having 512 KB, back to the PC1512 days, just being multi-core and having network access. :)

pjmlp 9y ago

I don't have any use for them, already enough side projects as it is, but the technical specifications of ESP32 are great. It is like having a PC1512 that fits on the pocket, there are already lots of programming languages that would fit on it.

fest 9y ago

And Espressif got their act together this time and are working on a good and open-source SDK (ESP-IDF). I just tried it out this week to make battery powered wireless temperature and humidity sensors. Sleep current for the whole system is not that great (~80uA of which 40-50 are used by ESP32 module). However, the simplicity and ease of use outweigh having to charge the battery every 3 months (3Ah li-ion cell).

MrBuddyCasino 9y ago
30-40uA with only the ULP running?
- fest 9y ago
  Now that you're asking- I don't really have an answer what exactly remains powered on. I have seen reports of people achieving sub-10uA sleep currents, so my result could be improved by a factor of 2 (LDO I put on board has Iq of ~40uA). I haven't looked really deep at what power modes are available for each power/clock domain- at the moment I just have the ESP waking up from RTC timer every 15 minutes and it can also be woken up manually with GPIO. It's entirely possible that I have left some peripherals at non-optimal state.
  - MrBuddyCasino 9y ago
    I see. I haven't explored the low-power states yet, the datasheet says 5µA is possible using hibernation and timer-controlled periodic wakeup. Was curious if those numbers are achievable.
    - michaelt 9y ago
      On the ESP8266 I was able to get down to 16.3 µA deep sleep current. A lot of easy-to-use modules come with a USB-serial converter and a 5v-to-3.3v converter. These will draw a few microamps even when there's no USB connected - and depending on the precise hardware, some will draw far more than that. You should plan on buying a few different modules and de-soldering a few components if you want to achieve the absolute minimum current consumption :)