This is the electrical control board on which the firmware runs.
The board receives stable 24V from an external power supply unit and requires around 16A of current at peak, but during almost all of the time it requires around 10A
of current (because the heaters are not fully on after having reached the target temperature).
On the board there's a switching regulator that converts the 24V to 5V, which is used by the endstops, the BLTouch and by the linear regulator
that instead converts the 5V to 3.3V which is used by the ESP32-S3-WROOM-1
microcontroller, the MT29F2G01ABAGDWB-IT NAND flash memory.
This is the electrical schematic of the board:
The PCB has 4 layers (PWR/SIGNAL, GND, GND, PWR/SIGNAL), this is an image of the top layer:
Some ideas for further improvement are:
- Add some little LEDs on the board to show that the power rails are good.
- Use an external Sigma-Delta ADC to improve the accuracy of the temperatures' readings (or calibrate the microcontroller's internal ADC).
- Put the antenna area of the ESP32 on the border of the PCB, to improve the antenna's performance.
- Change some connectors.