ESP32-S2-Saola-1 Development Board Circuit Analysis

dcexpert

ESP32-S2-Saola-1 Development Board Circuit Analysis [Copy link]

 

Before starting to use it, it is helpful to do a simple analysis of the circuit of the development board. The schematic diagram of the development board can be downloaded from the official website of Espressif ( ESP32-S2-Saola-1 schematic diagram ).

System Block Diagram

It can be seen that the ESP32-S2-Saola-1 development board consists of an ESP-S2 module, a USB-to-serial port, startup control, RGB lights, and a connector, which is very concise.

USB

The schematic diagram and physical picture of the USB part are as above.

The USB connector uses the traditional microUSB instead of the popular type-C interface, so you need to prepare an extra microUSB cable.

A bit odd is the use of 3 separate ESD diodes on the USB power and signal lines, rather than using an integrated ESD device to save space.

By default, the USB D+ and D- are connected to the USB to TTL chip CP2102. Since the ESP32-S2 has USB function, the board also has resistors R22/R23 for connection. However, soldering 0201 resistors will be difficult for most people without special tools. It is better to use a dip switch or 0603 resistor, or use a solder pad to short-circuit like the ST board.

The system's 5V power supply is obtained from the USB's VBUS through a Schottky diode 1N5819.

dcexpert

ESP32-S2

The core device is the ESP32-S2 module, which has the same size as the ESP32-WROOM module, but it should be noted that the pins are not compatible, so they cannot be directly replaced.

dcexpert

power supply

The power supply of the ESP32-S2-Saola-1 development board uses the domestic voltage regulator chip SGM2212-3.3, which is a power chip of Shengbang Micro and is compatible with 1117. Two 0603 10uF non-polarized capacitors are used at the front and back ends of the power supply. Generally, there should be no problem, but the performance is unknown when the power changes rapidly, and further testing is required (some copycat boards are prone to 3.3V voltage drop when the output power changes greatly, causing ESP32 to reset).

dcexpert

dcexpert posted on 2020-7-3 14:53 Reserved

The USB to TTL converter uses the common CP2102, which is the same as many ESP8266, NodeMCU and other boards. The DTR and RTS signals are introduced as firmware update control. The advantage is that it supports one-click update, but the disadvantage is that some software does not use DTR and RTS, so the program may not run normally.

9zhmke

This design seems to be more affordable.

dcexpert

9zhmke posted on 2020-7-5 10:54 With this design, the price should be more affordable

I saw a module for 9.9 yuan.

darichile

dcexpert posted on 2020-7-5 17:01 I saw a module for 9.9 yuan.

Is it the ESP-12K from Anxin?

dcexpert

darichile posted on 2020-8-27 17:17 Is it the ESP-12K of Anxinke?

Yes