Flow breakout board

The flow breakout board contains a VL53L0x ranging sensor as well as a PMW3901 optical flow sensor. It is the breakout version of the Crazyflie 2.0 Flow deck.

The signal names are marked on the board:

Both sensors are powered by the VCC and GND pins. The board accepts from 3V to 5V, two voltage regulators are generating the required voltage for the sensors and the board has voltage translator for the data signals.

The VL53L0 ranging sensor is facing front on the board. It is accessible on the I2C pins SCL and SDA.

The PMW3901 optical flow sensor is facing front on the board. Is is accessible on the SPI pins CS, MISO, MOSI, CLK. The pins MOTION and /RESET are also connected to the PMW3901. The reset pin can be left floating if not needed.

The optical flow sensor will output motion count. Assuming the board is moving above a flat surface the X/Y orientation is as follow:

You can install Arduino libraries using the Arduino library manager.

The VL53L0x has been succesfully tested with the following drivers:

• https://github.com/adafruit/Adafruit_VL53L0X
• https://github.com/pololu/vl53l0x-arduino

The PMW3901 arduino driver is https://github.com/bitcraze/Bitcraze_PMW3901.

• VL53L0x ToF sensor to measure distance up to 2 meters
• PMW3901MB Optical Motion Tracking Chip (datasheet)
• Input and signal voltage from 3V to 5V
• Mechanical specification:
  • Weight: 2.7g
  • Size (WxHxD): 20x26x4mm

Flow breakout schematic: flow_breakout_revb.pdf.