The Espressif ESP32 devices are getting everywhere: they are inexpensive, readily available and Espressif IDF environment and build system actually is pretty good and working well for me including Eclipse (see “Building and Flashing ESP32 Applications with Eclipse“). The default way to program an ESP32 is to a) enter UART bootloader by pressing some push buttons and b) flash the application with ESP-IDF using a USB cable.
That works fine if the ESP32 is directly connected to the host PC. But in my case it is is behind an NXP Kinetis K22FX512 ARM Cortex-M4F microcontroller and not directly accessible by the host PC. So I had to find a way how to allow boot loading the ESP32 through the ARM Cortex-M which is the topic of this article.
The new semester is approaching in a very fast way, and so is the new lecture and lab module ‘Advanced Distributed Systems’ at the Lucerne University. For that module we are going to build a new ‘Sumo’ style robot with WLAN capabilities using the ESP32 chip. It will be a new robot PCB, and below is the current robot (based on NXP K22FX512) with the WLAN module connected to it: