The IR Sensor for Brake Disc Temperature Measurements measures brake disc temperatures in an array of 16x4 pixels. I.e 16 temperatures in height and 4 temperatures in width.
A map reduce is done, such that for each 4 temperatures in width, the median is calculated, resulting in 16 temperatures representing the brake disc surface temperature.
Further, the average and max value of these 16 temperatures is calculated. The average, max and the 16 surface temperatures are sent over Bluetooth LE at a frequency of 50Hz, together with the core temperature of the nRF52 SoC and the IR sensor. Optionally the brake disc temperatures can be collected by a Bluetooth LE to CAN gateway (BLE2CAN), which redistributes the brake disc temperatures onto a CAN bus.
Sensor data (preliminary):
- Temp. meas. range: -20 to 900°C (optionally 1100°C)
- Max temp electronics: 85°C
- Meas freq: 1,2,4,8,16,32,64,128,256,512Hz (default 64Hz)
- Emmisivity: 0.01-1.0 (default 0.57)
- Field of view: 60° x 8°
- Resolution: 15-18 bit (16 bit default)
- Bluetooth LE max reporting freq (constrained by the BLE spec)
- Default 20ms (50Hz)
- BLE2CAN gateway: 7.5 ms (133Hz)
- IOS, Android: 20ms
- Weight: 15g + cable
- Supply Voltage: Min 2.7V, Max 15V
- Current consumption: Avg 10mA when measuring. 6µA when sleeping
- Enclosure: 3D printed ABS alternatively High Temperature ABS
- Dimensions (mm): 12.5x37x38/27 (WxLxH front/rear)