Wiring Diagram

Wiring diagram

This page shows the default wiring for the available board targets.

The inverter UART pins, RS485 direction pin, DS18B20 pin and status LED pin can all be changed later in the Web UI under Device Settings if you want to use a different layout.

wemos_d1_mini32:

This layout is meant as a drop-in replacement for the old D1 Mini style wiring.

Function	GPIO	D1 Mini label
Inverter RX to ESP32	GPIO19	D6
Inverter TX from ESP32	GPIO23	D7
RS485 DE / RE	GPIO18	D5
DS18B20 data	GPIO21	D2
Status LED	GPIO2	D4

ESP32-C3 SuperMini:

This target keeps the default wiring away from the USB pins.

Function	GPIO
Inverter RX to ESP32	GPIO20
Inverter TX from ESP32	GPIO21
RS485 DE / RE	GPIO10
DS18B20 data	GPIO3
Status LED	not used by default

ESP32-S3 SuperMini:

This target keeps the default wiring within the normal solder-pad pins and leaves the native USB pins free.

Function	GPIO
Inverter RX to ESP32	GPIO16
Inverter TX from ESP32	GPIO15
RS485 DE / RE	GPIO7
DS18B20 data	GPIO6
Status LED	not used by default

Waveshare ESP32-S3 ETH:

This target includes both inverter wiring and the default Ethernet module wiring.

Inverter / sensor wiring

Function	GPIO
Inverter RX to ESP32	GPIO17
Inverter TX from ESP32	GPIO18
RS485 DE / RE	GPIO15
DS18B20 data	GPIO21
Status LED	not used by default

Ethernet module wiring

Ethernet signal	GPIO
W5500 MISO	GPIO12
W5500 MOSI	GPIO11
W5500 SCLK	GPIO13
W5500 CS	GPIO14
W5500 RST	GPIO9
W5500 INT	GPIO10

RS232

Use a MAX3232 or equivalent level shifter between inverter serial and the ESP board.

• ESP TX -> level shifter RX -> inverter RX
• ESP RX <- level shifter TX <- inverter TX
• common ground is required

RS485

Use an RS485 transceiver such as MAX485, SN75176, SP3485 or equivalent.

• UART TX / RX use the selected board pins shown above
• DE / RE direction control uses the board-specific default pin shown above
• common ground is required

Ethernet

For the waveshare_esp32_s3_eth target the firmware expects a W5500 SPI Ethernet connection.

• use 3.3V
• connect GND
• connect MISO, MOSI, SCLK, CS, RST and INT

Notes

• ESP32-C3 native USB uses GPIO18 and GPIO19. The default esp32c3_supermini wiring leaves these free.
• ESP32-S3 native USB uses GPIO19 and GPIO20. The default esp32s3_supermini and waveshare_esp32_s3_eth wiring leaves these free.
• The current DS18B20 implementation supports up to 15 sensors on one shared 1-Wire bus.
• If you are unsure about the serial path, use the loopback test from the Debug page before connecting the inverter.