Air-Quality-Monitor
Schematic and PCB design of an air quality monitor.
Description
This WiFi switch module utilises the ESP-12E/F adaptor.
Programs
There are two ways of programming this piece of hardware:
- Program both the AVR chip on the Arduino board and the ESP8266 chip on the ESP-12E/F board.
- Program only the AVR chip on the Arduino board.
The first approach is recommended, since it exhibits more flexibility and the program is more structured. For this approach, please refer to Arduino program and ESP8266 program in the Indoor-Air-Quality-Monitoring-and-Control-System repository, respectively.
If you insist to use the second approach, please leave the original firmware in the ESP8266 chip as it is and use Arduino program for the Arduino board. In this way, you may also need a TCP server to receive the data from the sensor, an example of the server program is here, publish_office_air_quality.py in the Indoor-Air-Quality-Monitoring-and-Control-System repository.
For both approaches, make sure the baud rate of the Arduino and the ESP-12E/F boards are the same. If you use the second approach, the default baud rate of the ESP-12 board is 115200, which can be changed (say to 57600) using an AT command as AT+CIOBAUD=57600 and checked by AT+CIOBAUD?. I was not successful at changing the baud rate of the ESP-12 board, but was successful on an ESP-03 board. Besides, the baud rate of 115200 was exceedingly unreliable between Arduino Pro Mini 3.3V version and ESP8266, and I have to reduce it to at most 57600 in order to make the communication work. I had no idea of why these mysteries happened, so if anybody finds the reason, please do let me know.
The Finished Board
