Qwiic Distance Sensor (RFD77402) Hookup Guide
Contributors:
Englandsaurus
Englandsaurus 
Hardware Overview
Let's first check out some of the characteristics of the RFD77402 sensor we're dealing with, so we know what to expect out of the board.
| Characteristic | Range |
|---|---|
| Operating Voltage | 3.3V |
| Current | 7 mA average at 10Hz |
| Measurement Range | ~50mm to 2,000mm |
| Precision | +/-10% |
| Light Source | 850nm VCSEL |
| I2C Address | 0x4C |
| Field of View | 55° |
| Field of Illumination | 23° |
| Max Read Rate | 10Hz (We've seen up to 20Hz in practice) |
Pins
The following table lists all of the RFD77402's pins and their functionality.
| Pin | Description | Direction |
|---|---|---|
| GND | Ground | In |
| 3.3V | Power | In |
| SDA | Data | In |
| SCL | Clock | In |
| INT | Interrupt, goes low when data is ready. | Out |
Optional Features
The RFD77402 breakout has onboard I2C pull up resistors; if multiple sensors are connected to the bus with the pull-up resistors enabled, the parallel equivalent resistance will create too strong of a pull-up for the bus to operate correctly. As a general rule of thumb, disable all but one pair of pull-up resistors if multiple devices are connected to the bus. If you need to disconnect the pull up resistors they can be removed by removing the solder on the corresponding jumpers highlighted below.
