On-Board Sensors, Inputs, And Indicators; Temperature Sensor; Photocell (Light Sensor); User Led 1 (Red) - NXP Semiconductors TWR-RF-SNAP User Manual

3.3 On-board Sensors, Inputs, and Indicators

The following interfaces are implemented in the TWR-RF-SNAP to allow for user interaction.

Temperature Sensor:

- Connected to ADC Ch. 1 (physical pin 9 of the SM700) – SNAP GPIO 31
- Low-Power Linear Active Thermistor IC
- Analog output

Photocell (Light Sensor):

- Connected to ADC Ch. 0 (physical pin 8 of the SM700) – SNAP GPIO 30
- Analog output
Power Switch:
- Left position – Draws power from the battery connector
- Middle position – OFF
- Right position – Draws power from the tower elevator or USB port

User LED 1 (Red):

- Connected to TMR0 (physical pin 34 of the SM700) – SNAP GPIO 8
- Activated by setting the pin HIGH

User LED2 (Green):

- Connected to TMR1 (physical pin 33 of the SM700) – SNAP GPIO 9
- Activated by setting the pin HIGH

Power LED:

- Green LED (D5) will indicate when power is applied to the board

Switch 2 (software accessible input):

- Connected to Physical Pin 57 of the SM700 – SNAP GPIO 22
- KBI pin – wake from sleep interrupt capable
- Switch is grounded when pressed

Switch 3 (software accessible input):

- Connected to Physical Pin 56 of the SM700 – SNAP GPIO 23
- KBI pin – wake from sleep interrupt capable
- Switch is grounded when pressed

Reset Button:

- Push button tied directly to RESET on the SM700 / Reboots the device
TWR-RF-SNAP User's Manual Page 9 of 22