Onboard Sensors

TPP2(G3) is equipped with one onboard temperature sensor and accelerometer. Having these sensors onboard enables the design of fail-safe scenarios and a range of applications that need tilt, orientation or constant movement detection. These sensors are placed on the same I2C bus as the EEPROM, therefore you can access them through TiOS syscalls, instead of i2c/ssi objects. These sensors are not continuously sampled by TiOS on the backend, which means each time, the sensor should be polled from the Tibbo BASIC application.

Onboard Temperature Sensor

The onboard MCP9808 sensor can measure temperatures in the range of -42°C to 125°C. The built-in sys.boardtemp syscall can be used to measure the board temperature in degrees Celsius. The sensor is located close to the CPU and other critical components of the system.

Onboard Accelerometer

The onboard accelerometer is ADXL312, which can measure ±6g, with 2.5mg resolution.

The following steps are required for its use:

1. Enabling of sensor: via sys.configaccel
2. Capturing the sensor: via sys.captureaccel; calling this takes a snapshot of all 3 axes.
3. Read the axes values: via sys.readaccelx, sys.readaccely and sys.readaccelz

Step 1 is only required to be called 1 time in application, but each time the sensor is polled, step 2 and 3 are required.

1g ≈ 9.8m/s^2