ESP32-C3

Overview

I love RISC-V. Maybe cuz I worked on it for a long time during my internship at Huawei and I sort of know the instruction set inside out. I want to make a board using the ESP32-C3, cuz its cheap.

Documents

• Hardware Design Guidelines: must-have components on the PCB and recommended specs
• Datasheet: not much use for an MCU, mostly refer to the pin configurations and numbers
• Technical Reference Manual: internal workings of the chip, not too important until you need to fiddle with the registers

Minimal Board Setup

Digital Power

• Use recommended cap values

Analog Power Supply

• Use recommended LC filter and caps

Power-on sequence

• Use RC delay / latch circuit to delay power-on after 3.3V has stabilised

Clock Crystal

• 10ppm and 40MHz
• Capacitor values: https://blog.adafruit.com/2012/01/24/choosing-the-right-crystal-and-caps-for-your-design/

RF Circuit

• pi-matching is ideal but not compulsory, its just a lower gain mate

Strapping Bins (i.e. boot config)

• GPIO 2, 8, 9
• just do pull-up or pull-down resistors and jumper wire

Use CDC USB

Using CDC USB for serial console and programming means you can save the space of a CH340g. Just set your serial console output in ESP-IDF to CDC USB