Skip to content

BUILDING.md

Latest commit

 

History

History
115 lines (91 loc) · 5.21 KB

BUILDING.md

File metadata and controls

115 lines (91 loc) · 5.21 KB

warning

Be warned! This design is currently still evolving, and parts may be swapped around or added in the future.

parts

dev boards:

  • esp32 dev board, any will do, but ideally go for one with 38 pins. berrybase link.
  • scd41 (co2 sensor). personally I've used the seeed studios breakout board. berrybase link, seeedstudio link. adafruit's one will do too.
  • Optional: bmp180 (pressure sensor). I don't like this sensor and I'll swap it later. If this is not found on the i2c chain it will automatically be disabled. berrybase link, direnc.net link
  • Optional: waveshare 2.13in 250x122 e-ink display, not the raw display, but one with a built-in driver board. I've personally used the raspberry pi hat. Screen can be disabled in config. waveshare link

also, of course:

  • 10k resistors. You'll use up to half a dozen of them. Get a size you're comfortable soldering.
  • Optional, but useful: Capacitors, 10uF, ceramic, etc. I used one that was 10uF 25VDC 10% X7R 1210 SMD.
  • Optional: If you want a switch for bluetooth or wifi, get small latching switches (SPDT).

example wiring

note: not all GPIOs are usable on an esp32, as some are https://randomnerdtutorials.com/esp32-pinout-reference-gpios/

G27 -> SCD41 SCL (yellow)
G26 -> SCD41 SDA (white)
SCD41 SCL -> BMP180 SCL (yellow)
SCD41 SDA -> BMP180 SDA (white)
G33 -> wifi switch middle (brown)
G25 -> bt switch middle (blue)
G16 -> red LED (gray) (optional! if you don't wire it up, set it in config to null or just remove it entirely)

G23 -> screen DIN/MOSI (yellow)
G18 -> screen CLK/SCK (blue)
G19 -> screen CS (gray)
G21 -> screen DC (brown)
G22 -> screen BUSY (yellow)
G15 -> nothing (needed for nonexistent screen miso)

GND -> SCD41 GND (black)
GND -> wifi switch bottom (10k + black)
GND -> bt switch bottom (black)
GND -> screen GND (black)
GND -> red LED (resistor + black)

3V3 -> SCD41 PWR (red)
3V3 -> wifi switch top (10k + red)
3V3 -> bt switch top (10k)
3V3 -> screen VCC (red)

Nothing -> screen RST

More to come!

installing stuff

  • install latest stable micropython on your esp32
  • install the libraries in esp32/requirements.txt, see this link.
  • manually apply the following changes to the ble library you've installed micropython/micropython-lib#629 (if it is not yet merged).
  • copy esp32/config.json.template to esp32/config.json and configure it to your liking.
    • if you're on an esp32 variant without bluetooth (like esp32-s2), set bluetooth/enabled to false. you can then also omit the bt switch pin or set it to null.
    • if you don't want to wire up wifi pin, you can set it to null or just leave it out. it'll default to true.
    • if you're using hardware i2c, set i2c/use_softi2c to false and set peripheral_id (0 is usually fine).
    • if you're using hardware spi, set spi/use_softspi to false and set bus_id (on esp32-s2, you want 2 as 0/1 are for memory).
  • copy the files across:
pip3 install adafruit-ampy
cd esp32
ampy -p /dev/ttyUSB0 put main.py
ampy -p /dev/ttyUSB0 put config.json
ampy -p /dev/ttyUSB0 put helpers.py
ampy -p /dev/ttyUSB0 put influx_helpers.py
ampy -p /dev/ttyUSB0 put bmp180.py  # only if you have one
ampy -p /dev/ttyUSB0 put bmp280.py  # only if you have one
ampy -p /dev/ttyUSB0 put scd41.py
ampy -p /dev/ttyUSB0 put comic_code_24.py
ampy -p /dev/ttyUSB0 put comic_code_24.bin
ampy -p /dev/ttyUSB0 put comic_code_48.py
ampy -p /dev/ttyUSB0 put comic_code_48.bin
ampy -p /dev/ttyUSB0 put waveshare213.py
ampy -p /dev/ttyUSB0 put web_server.py
ampy -p /dev/ttyUSB0 put waveshare_lut_full_update.bin
ampy -p /dev/ttyUSB0 mkdir lib
ampy -p /dev/ttyUSB0 mkdir logs

then merely boot your board and watch it upload/broadcast/display your sensor values :)

parsing the screen

avenet42 screen

(1) Temp data from SCD41. Defaults to Celsius. Currently no way to change it to Fahrenheit.
(2) Relative Humidity data from SCD41.
(3) CO2 PPM data from SCD41.
(4) WLAN status indicator.
(5) Bluetooth status indicator.
(9) Baka display (free memory on the system. useful for watching for memory leaks. only shown if config["screen"]["debug"] is true).

fetching logs (if local logging is enabled)

ampy -p /dev/ttyUSB0 get logs/rh.log rh.log
ampy -p /dev/ttyUSB0 get logs/c.log c.log
ampy -p /dev/ttyUSB0 get logs/pressure.log pressure.log
ampy -p /dev/ttyUSB0 get logs/co2.log co2.log
ampy -p /dev/ttyUSB0 rm logs/rh.log
ampy -p /dev/ttyUSB0 rm logs/c.log
ampy -p /dev/ttyUSB0 rm logs/pressure.log
ampy -p /dev/ttyUSB0 rm logs/co2.log

can be viewed with tools/logparser.py: python3 logparser.py /tmp/co2.log