I connected the MHz19 sensor to the D1 mini and want to flash it via ESP-Home.
I followed the following guide: https://esphome.io/components/sensor/mhz19.html
I used the code
esphome:
name: co2-sensor
esp8266:
board: esp01_1m
# Enable logging
#logger:
# Enable Home Assistant API
api:
ota:
password: "xxxxxx"
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "Co2-Sensor Fallback Hotspot"
password: "xxxxx"
captive_portal:
uart:
rx_pin: GPIO3
tx_pin: GPIO1
baud_rate: 9600
sensor:
- platform: mhz19
co2:
name: "CO2 Value"
temperature:
name: "MH-Z19 Temperature"
update_interval: 60s
automatic_baseline_calibration: false
But cannot flash, I get the following error
======================== [SUCCESS] Took 305.85 seconds ========================
INFO Successfully compiled program.
esptool.py v3.2
Serial port /dev/ttyUSB0
Connecting......................................
A fatal error occurred: Failed to connect to ESP8266: No serial data received.
For troubleshooting steps visit: https://github.com/espressif/esptool#troubleshooting
INFO Upload with baud rate 460800 failed. Trying again with baud rate 115200.
esptool.py v3.2
Serial port /dev/ttyUSB0
Connecting......................................
A fatal error occurred: Failed to connect to ESP8266: No serial data received.
For troubleshooting steps visit: https://github.com/espressif/esptool#troubleshooting
I can however flash it and it comes online if I disconnect the sensor, of course it publishes no data. So I assume it's something to do with UART. I also tried disabling the logging, which did nothing.
It seems the UART pins used by default for debug logging, even though I thought I had disabled the logging option. I used pin 4 and 5 and it worked.
https://esphome.io/components/uart.html#uart
Note that the value I got was 5000 ppm at first, when it was plugged into the Pi on which I'm running HA. When connecting to another PSU I got 'normal' looking values. I assume it simply did not get enough power from the PI.