The Wirnet iBTS gateway can be powered with an Ethernet cable (PoE injector) or/and an auxiliary power supply (solar panel, battery). When both PoE and external power supply are plugged, the gateway uses the highest voltage available.

Power loss can be detected by polling the value of the VIN_9V signal. It should fall down near 0V when both, PoE and Aux power, are lost. The first action to take when the VIN_9V value decreases is to stop the LoRa module. This will decrease the consumption so the gateway will have enough time to stop. The voltage value can be obtained with the following methods:

root@klk-lpbs:~# adc 4
VIN_9V=48979mV

or:

  FILE * pf_file = NULL;
  u32    u32_adc_value = 0;
 
  pf_file = fopen ("/sys/bus/iio/devices/iio:device1/in_voltage0_raw", "r");
  if(pf_file != NULL)
  {
    fscanf (pf_file, "%d\n", &value);
    fclose (pf_file);
    pf_file = NULL;
  }
  u32_adc_value=( (value * 3300) / 4096 );
  u32_adc_value = ((u32_adc_value* 485) / 15);

An ON/OFF button is located on the front side of the CPU module. This button is intended to perform a hard reboot, power down and power up of the Wirnet iBTS:

• Hard reboot - Press the button of the Wirnet iBTS.
• Power down
  • Press the button between 1 to 5 seconds to halt the Wirnet iBTS.
  • Wait for the shutdown of the Wirnet iBTS i.e. until the LEDs are switched off.
  • The shutdown may take up to 30s depending on the current software activity.
• Power on - Press the button during 1 second to power on the Wirnet iBTS when powered off.

All internal voltage measurement can be obtained using the following tool:

root@klk-lpbs:~# adc
VDD_CORE=1372mV
NVCC_DRAM=1354mV
3V3_FDP=3283mV
NVCC_3V3=3288mV
VIN_9V=48435mV
VCC_5V=5008mV
VPOWER=9139mV
VPORT_MEAS=48435mV