This is here to document and give a name to the pinout used by some pre-wired SHT20/SHT30/etc sensors with GX12-4 female connectors on them, such as 'Taidacent GX12-4P GX12 4 Pin Temperature Humidity Probe Online Temperature and Humidity Meter Sensor SHT40/SHT30/SHTC3/SHT20 (GX12-4P-SHTC3-Metal)'.
| Pin | Color | I²C role |
|---|---|---|
| 1 | Red | Positive |
| 2 | Black | Ground |
| 3 | Green | SDA |
| 4 | Yellow | SCL |
See also: WSTYPE-4104, a different convention that I had come up with before these pre-wired ones appeared. The two conventions agree on pins 1 and 3 being for positive voltage power and SDA, respectively, but swap the roles of pins 2 and 4.
If you have connectors following both conventions in your collection, color-code them. WSTYPE-4106 with black and blue stripes, WSTYPE-4146 with black and red stripes.
See also: Qwiic, a convention for I2C over 4-pin JST connectors
with pinout: GND, 3V3, SDA, SCL.