Python Radio 7: The ESP32
More power!
The ESP32 is the big brother to the ESP8266.
It has two 32-bit processor cores on the chip, and a third less powerful processor for handling simple tasks while the more power-hungry cores sleep. It has over six times the RAM (520 KB) as the ESP8266 and runs at 240 MHz instead of 160 MHz. You can get one for about $12 at AliExpress.com.
Because it has several accessible hardware timers and UARTs (serial ports), it makes several radio projects possible that would be difficult to do with the smaller chip.
ASCII text by radio
The ESP32 has several UARTs (Universal Asynchronous Receiver-Transmitter) for sending serial data. This means we can use one for the USB connection to a laptop or desktop computer and still have fully functional serial data capabilities for sending bits to the radio. The ESP8266 only had the transmitting half of the serial port free for us to use.
We will use two ESP32 boards. The board we will call Ichabod will transmit messages to the board we will call Rumpelstiltskin.
We set up the UART to use pin 21 as output and pin 37 as input. If the machines are close together, a baud rate as high as 9600 will work, but for longer distances, a baud rate of 2400 works quite well, communicating without errors using…
