4 ms·

Nice, but I can't think of less power-efficient embedded platform than an RPi. Especially with something as low power as E-Ink (zero power when displaying). In

Nice, but I can't think of less power-efficient embedded platform than an RPi. Especially with something as low power as E-Ink (zero power when displaying). Innophase T2, Dialog DA16200, RedPines (SiLabs) RS9116, RealTek Ameba... they all are super low power (like 100x less than RPi) even while maintaining the 802.11 association, and come with easy SDKs ready for REST HTTPS out of the box (and RTC capabilities, not sure about the ameba).

mwcampbell 5y ago
How does ESP32 compare to the products you listed?
- dheera 5y ago
  I find the ESP32 much easier to develop for, you don't need to install any toolchains, just plug in and drop code into the virtual USB drive that shows up! I wish all microcontrollers were like that these days.
  - BoorishBears 5y ago
    That sounds like a very specific bootloader that you're using ESP-IDF is still very nice though, and being CMake based makes it easy to integrate outside code It supports serial based uploads, which are still pretty nice with the bundled serial monitor (one key combo to build, upload, and restart) and OTA uploads
    - dheera 5y ago
      Oh sure, but it's still way better than the last time I had to deal with an STM32 and install about 5 different things, modify a "boards.txt" file (which there were 3 copies of on my system in different places and I had no idea which was the real one) and then hit the program button with one hand with a mouse in the air while carefully timing a short of a reset trace on a PCB with the other with my elbow holding down the PCB. STM32s really suck. Never had to do that with an ESP32, at least someone made a nice bootloader for it.
  - fcsp 5y ago
    How do you handle SSL? I found this very cumbersome in my experiments with esp32
    - stavros 5y ago
      It depends on whether you want to connect to random hosts or ones that you know beforehand. The latter is very easy, I just hardcode the certificate fingerprint. The former/dealing with CAs is harder, I've never done it.
    - SavantIdiot 5y ago
      I never coded on Espressif, but in other SDKs (e.g., mosquitto, mbedtls) typically this is done when you open the connection at the application layer (HTTPS, MQTTS). You pass in the cert bytes either as binary or PEM text as a char[]. Use a CA root cert(s) from your OS/browser. EDIT: grammar and typos.
    - konschubert 5y ago
      The high-level client in esp-idf handles ssl out of the box and comes with a list of pre-installed root cas. The question, of course, is: What if these CAs expire?
- SavantIdiot 5y ago
  I wanted to try their Espressif ESP32 low power 802.11 part back in March but it wasn't shipping yet. Their website isn't clear but I'll poke around and see if it has been released yet.
- baybal2 5y ago
  ESP32 is a very generic synthesized chip, not particularly ULP oriented. On other hand, it's the most developer friendly company out there. I've been unsuccessful getting any proper reaction from Innophase about SDK support. Their sales seem to not even understand what we are wanting from them, and keep sending us "enter these AT commands through USB-TTL" ESP32 is also pretty much the one, and only wireless MCU you can buy on the open market, in any quantity, on a short notice. Nothing else comes with the supply chain security like this.
  - kelnos 5y ago
    > ESP32 is a very generic synthesized chip, not particularly ULP oriented. Maybe not, but setting it up to sleep most of the time and only boot once a day to fetch the calendar and update the display should sip power pretty sparingly; I expect you'd get months if not a year or more before needing to recharge the battery.
miohtama 5y ago
Can you keep RPi most of the time hibernated? Does it still draw a lot of power in sleep?
- kelnos 5y ago
  You don't really need to "hibernate"; shutting the entire system down and booting from scratch on each update is simpler and probably more reliable. The problem (hibernate or not) is getting the Pi to wake up, since it doesn't have a real-time clock. OP is using a RTC hat to achieve this. I do wonder what kind of power consumption it uses while sleeping.
  - SavantIdiot 5y ago
    what a colossal kludge. what you're trying to accomplish is basically embedded programming 101: sleep mode + wakeup timer. RTC? pff.. even any MPU on-board oscillator with no crystal has good enough PPM and lower power than an RTC. your solution is like hunting quail with a nuke.
    - KaiserPro 5y ago
      yes, but trying to generate a nice rendered image on a stand-alone uProcessor is pretty hard. I don't like that it takes headless chrome to render, but it _works_ and fills a need for the maker. I'm pretty sure they looked at the stuff they'd need to write (A layout engine, a anti aliasing library, a calendar parsing library, an image handling library) and thought "fuck that, lets use a pi". It terms of time thats weeks full time, and even then might not be possible to fit on the uCPU of choice. just buy a realtime hat with wake up ability, for $40 max, boom job done moving to making the thing look good. Its not a product, its someone's hobby, leave them be.
      - SavantIdiot 5y ago
        > trying to generate a nice rendered image on a stand-alone uProcessor is pretty hard. Did you see the rendering? It is very simple, and does not require PIL. There are plenty of embedded GUI libraries that are specifically for this kind of application (uFX, Qt). Why not learn something new? I want HN to be a place where experts critique ideas, not a Facebook/Instagram like-fest ego-stroke. I was proposing a deeper dive to the OP so that s/he could develop better skills. I wasn't mocking OP, but I was mocking your bad idea because you didn't make anything, you just threw out a naive suggestion. Did you come here to learn or to get some karma for a dopamine hit?
ashtonkem 5y ago
I was going to say, I feel like an ESP32 might be a better fit for this, given that it’s designed for deep sleep.
turtlebits 5y ago
Sure, there are more power efficient platforms, but the project uses Selenium and PIL which I’m pretty sure won’t run on any of those boards.
- micheljansen 5y ago
  I guess you could offload the rendering to a server, but then it’s no longer a self-contained, standalone solution. Trade-offs!
deleted 5y ago
[deleted]

mwcampbell 5y ago

How does ESP32 compare to the products you listed?

dheera 5y ago
I find the ESP32 much easier to develop for, you don't need to install any toolchains, just plug in and drop code into the virtual USB drive that shows up! I wish all microcontrollers were like that these days.
- BoorishBears 5y ago
  That sounds like a very specific bootloader that you're using ESP-IDF is still very nice though, and being CMake based makes it easy to integrate outside code It supports serial based uploads, which are still pretty nice with the bundled serial monitor (one key combo to build, upload, and restart) and OTA uploads
  - dheera 5y ago
    Oh sure, but it's still way better than the last time I had to deal with an STM32 and install about 5 different things, modify a "boards.txt" file (which there were 3 copies of on my system in different places and I had no idea which was the real one) and then hit the program button with one hand with a mouse in the air while carefully timing a short of a reset trace on a PCB with the other with my elbow holding down the PCB. STM32s really suck. Never had to do that with an ESP32, at least someone made a nice bootloader for it.
- fcsp 5y ago
  How do you handle SSL? I found this very cumbersome in my experiments with esp32
  - stavros 5y ago
    It depends on whether you want to connect to random hosts or ones that you know beforehand. The latter is very easy, I just hardcode the certificate fingerprint. The former/dealing with CAs is harder, I've never done it.
  - SavantIdiot 5y ago
    I never coded on Espressif, but in other SDKs (e.g., mosquitto, mbedtls) typically this is done when you open the connection at the application layer (HTTPS, MQTTS). You pass in the cert bytes either as binary or PEM text as a char[]. Use a CA root cert(s) from your OS/browser. EDIT: grammar and typos.
  - konschubert 5y ago
    The high-level client in esp-idf handles ssl out of the box and comes with a list of pre-installed root cas. The question, of course, is: What if these CAs expire?
SavantIdiot 5y ago
I wanted to try their Espressif ESP32 low power 802.11 part back in March but it wasn't shipping yet. Their website isn't clear but I'll poke around and see if it has been released yet.
baybal2 5y ago
ESP32 is a very generic synthesized chip, not particularly ULP oriented. On other hand, it's the most developer friendly company out there. I've been unsuccessful getting any proper reaction from Innophase about SDK support. Their sales seem to not even understand what we are wanting from them, and keep sending us "enter these AT commands through USB-TTL" ESP32 is also pretty much the one, and only wireless MCU you can buy on the open market, in any quantity, on a short notice. Nothing else comes with the supply chain security like this.
- kelnos 5y ago
  > ESP32 is a very generic synthesized chip, not particularly ULP oriented. Maybe not, but setting it up to sleep most of the time and only boot once a day to fetch the calendar and update the display should sip power pretty sparingly; I expect you'd get months if not a year or more before needing to recharge the battery.

miohtama 5y ago

Can you keep RPi most of the time hibernated? Does it still draw a lot of power in sleep?

kelnos 5y ago
You don't really need to "hibernate"; shutting the entire system down and booting from scratch on each update is simpler and probably more reliable. The problem (hibernate or not) is getting the Pi to wake up, since it doesn't have a real-time clock. OP is using a RTC hat to achieve this. I do wonder what kind of power consumption it uses while sleeping.
- SavantIdiot 5y ago
  what a colossal kludge. what you're trying to accomplish is basically embedded programming 101: sleep mode + wakeup timer. RTC? pff.. even any MPU on-board oscillator with no crystal has good enough PPM and lower power than an RTC. your solution is like hunting quail with a nuke.
  - KaiserPro 5y ago
    yes, but trying to generate a nice rendered image on a stand-alone uProcessor is pretty hard. I don't like that it takes headless chrome to render, but it _works_ and fills a need for the maker. I'm pretty sure they looked at the stuff they'd need to write (A layout engine, a anti aliasing library, a calendar parsing library, an image handling library) and thought "fuck that, lets use a pi". It terms of time thats weeks full time, and even then might not be possible to fit on the uCPU of choice. just buy a realtime hat with wake up ability, for $40 max, boom job done moving to making the thing look good. Its not a product, its someone's hobby, leave them be.
    - SavantIdiot 5y ago
      > trying to generate a nice rendered image on a stand-alone uProcessor is pretty hard. Did you see the rendering? It is very simple, and does not require PIL. There are plenty of embedded GUI libraries that are specifically for this kind of application (uFX, Qt). Why not learn something new? I want HN to be a place where experts critique ideas, not a Facebook/Instagram like-fest ego-stroke. I was proposing a deeper dive to the OP so that s/he could develop better skills. I wasn't mocking OP, but I was mocking your bad idea because you didn't make anything, you just threw out a naive suggestion. Did you come here to learn or to get some karma for a dopamine hit?

ashtonkem 5y ago

I was going to say, I feel like an ESP32 might be a better fit for this, given that it’s designed for deep sleep.

turtlebits 5y ago

Sure, there are more power efficient platforms, but the project uses Selenium and PIL which I’m pretty sure won’t run on any of those boards.

micheljansen 5y ago
I guess you could offload the rendering to a server, but then it’s no longer a self-contained, standalone solution. Trade-offs!

deleted 5y ago

[deleted]