ChirpStack JS decoder for VEGA TS-11 (https://en.iotvega.com/product/tester) payloads

decode.js

// Decode decodes an array of bytes into an object.
//  - fPort contains the LoRaWAN fPort number
//  - bytes is an array of bytes, e.g. [225, 230, 255, 0]
//  - variables contains the device variables e.g. {"calibration": "3.5"} (both the key / value are of type string)
// The function must return an object, e.g. {"temperature": 22.5}
function Decode(fPort, bytes, variables) {
  output = {}
  if (fPort == 4) {
    flag_bits = bytes[0].toString(2).split('').reverse()

    if (flag_bits[0] == 1) {
      output.rssi = -bytes[5]
      output.snr = bytes[6] > 127 ? bytes[6] - 256 : bytes[6]
    }

    if (flag_bits[1] == 1) {
      output.battery_voltage_mV = (bytes[3] << 8) + bytes[4]
    }

    if (flag_bits[2] == 1) {
      output.downlink_packet_count = bytes[2]
    }

    if (flag_bits[3] == 1) {
      output.uplink_packet_count = bytes[1]
    }

    if (flag_bits[4] == 1) {
      output.navigation_data_available = true
    }

    if (flag_bits[5] == 1) {
      output.send_by_timer_event = false
      output.send_by_button_press_event = true
    } else {
      output.send_by_timer_event = true
      output.send_by_button_press_event = false
    }

    if (flag_bits[6] == 1) {
      output.temperature_data_available = true
    }
  }
  return output
}