There are few ways to read data from the sensor:
- from PWM output
- from serial port
- from V0 - analog output (not checked)
This project uses the serial port (works more stable).
Connect the sensor, when data are read from the sensor's serial port.
ESP32 | CO2 sensor MH-Z19B
pin 16 (RX2) - TX
pin 17 (TX2) - RX
GND - GND
+5V - Vin
Temperature and humidity sensor DHT-11
ESP32 | Temperature and humidity sensor DHT-11
+3.3V - 1 (see an image below)
pin 21 - 2
(NC) - 3
GND - 4
Connect the display
ESP32 | Display Nokia 5110
pin 14 - Serial clock out: CLK (SCLK)
pin 13 - Serial data out: DIN
pin 27 - Data/Command select: DC (D/C)
pin 15 - LCD chip select: CE (CS)
pin 26 - LCD reset: RST
5V - VCC
GND - GND
The project uses the display library U8g2(download), which supports large number of display types (set in the code a selected display from this list).
Similar project on an Arduino. This project uses Adafruit GFX Library and Adafruit PCD8544 Nokia 5110 LCD library.
For support of the temperature and humidity sensor DHT-11 - it is used a library https://github.com/RobTillaart/Arduino/tree/master/libraries/DHTstable (download, zip, install to Arduino)
Basic setup:
Serial interface log - demonstration of a deep sleep mode (sketch with sleep state)
