Hardware notes¶

Schematics¶

The original schematics, BOM and Gerber files can be found at https://oshwhub.com/sunnygold/esp32s3-si4732-shou-yin-ji. A copy of the files is available at https://github.com/esp32-si4732/esp32-si4732-oshwhub

Datasheets¶

ESP32-S3-WROOM-1 - MCU SoC
SI4732-A10 1, 2, 3, 4 - broadcast radio receiver
ST7789 - LCD controller (also see the GC9307-XL caveat)
GC9307 - LCD controller
NS4160 - audio amplifier
AD4150B - audio amplifier
ME6217 - LDO regulator
TP4056 - battery charge controller

Pinout¶

The pinout table is shown below.

The relevant columns are ESP32-S3-WROOM-1 “Pin Name” and “ATS-Mini Sketch Pin Definitions”

ESP32-S3-WROOM-1 Pin #	ESP32-S3-WROOM-1 Pin Name	ATS-MINI Sketch Pin Definitions	TFT_eSPI Pin Definition	xtronic.org Schematic	Comments Info
1	GND			GND
2	3V3			VCC_33
3	EN			EN	RST Button
4	IO4	VBAT_MON		BAT_ADC	Battery monitor
5	IO5		TFT_RST	LCD_RES
6	IO6		TFT_CS	LCD_CS
7	IO7		TFT_DC	LCD_DC
8	IO15	PIN_POWER_ON		RADIO_EN	1= Radio LDO Enable
9	IO16	RESET_PIN		RST	SI4732 Reset
10	IO17	ESP32_I2C_SCL		I2C_SCL	SI4732 Clock
11	IO18	ESP32_I2C_SDA		I2C_SDA	SI4732 Data
12	IO8		TFT_WR	LCD_WR
13	IO19			USB_DM	USB_D- (CDC Port)
14	IO20			USB_DP	USB_D+ (CDC Port)
15	IO3	AUDIO_MUTE		MUTE	1 = Mute L/R audio
16	IO46		TFT_D5	LCD_DS
17	IO9		TFT_RD	LCD_RD
18	IO10	PIN_AMP_EN		AMP_EN	1 = Audio Amp Enable
19	IO11			NC	Spare
20	IO12			NC	Spare
21	IO13			NC	Spare
22	IO14			NC	Spare
23	IO21	ENCODER_PUSH_BUTTON		SW	Rotary encoder SW signal
24	IO47		TFT_D6	LCD_D6
25	IO48		TFT_D7	LCD_D7
26	IO45		TFT_D4	LCD_D4
27	IO0			GPIO0	BOOT button
28	IO35			NC	Used for OSPI PSRAM
29	IO36			NC	Used for OSPI PSRAM
30	IO37			NC	Used for OSPI PSRAM
31	IO38	PIN_LCD_BL	TFT_BL	LCD_BL	Backlight control
32	IO39		TFT_D0	LCD_D0
33	IO40		TFT_D1	LCD_D1
34	IO41		TFT_D2	LCD_D2
35	IO42		TFT_D3	LCD_D2
36	RXD0			NC	GPIO44
37	TXD0			NC	GPIO43
38	IO2	ENCODER_PIN_A		A	Rotary encoder A signal
39	IO1	ENCODER_PIN_B		B	Rotary encoder B signal
40	GND			GND
41	EPAD			GND

BOOT and RESET buttons¶

Some of the ESP32-SI4732 receivers do not have the BOOT and RESET buttons soldered in. You will need these buttons if you want to recover a receiver that was bricked because of a failed flashing process. Here is how to add the BOOT & RESET buttons.