Reach M2 not booting, Under-voltage detected

Another problem from my side:
When connecting the Reach M2 receiver to the navio2 board, it rarely boots and only orange light is on.
At the same time, the raspberry pi reports under voltage detections. Here two plug in events.

Nov 12 16:30:03 navio kernel: [ 348.011006] Under-voltage detected! (0x00050005)
Nov 12 16:30:09 navio kernel: [ 354.250994] Voltage normalised (0x00000000)
Nov 12 16:31:43 navio kernel: [ 447.851411] Under-voltage detected! (0x00050005)
Nov 12 16:31:47 navio kernel: [ 452.011317] Voltage normalised (0x00000000)


  • the Navio2 is powered with the delivered PowerModule v2.0
  • Reach M2 module is connected via S1 to the Navio2 UART Port

I sometimes get it running by unplugging and replugging it for a few times.
Using a USB Charger it is booting without problems…

Report after attaching it to the power plug

Simple system report
app version: 2.24.0-r0
'wifi_status, interface: wlan0':
- wifi_mode: infrastructure
- ip: 192.168.178.xx
  is_added: true
  is_connected: true
  is_visible: false
  mac_address: xxxx
  security: wpa-psk
  ssid: xxx
  uuid: xxx
base mode:
  base coordinates:
    accumulation: 2.0
    antenna offset:
      east: '0'
      north: '0'
      up: '0'
    - 0
    - 0
    - 0
    format: llh
    mode: single-and-hold
    enabled: true
    io_type: tcpsvr
    port: 9000
  rtcm3 messages:
      enabled: true
      frequency: 0.10000000000000001
      enabled: true
      frequency: 1.0
      enabled: true
      frequency: 1.0
      enabled: false
      frequency: 1.0
      enabled: false
      frequency: 1.0
  discoverable: false
  enabled: false
  pin: '***'
  duty cycle: 20
  enable: false
  period: 2
  polarity: false
    - - 863000
      - 870000
correction input:
    baud_rate: 57600
    device: UART
    enabled: true
    io_type: serial
    send_position_to_base: true
  night_mode: false
  privacy_policy_accepted: true
  usage_analysis_accepted: false
    format: RTCM3
    started: true
    format: RTCM3
    started: true
  debug: false
  interval: 24
  overwrite: true
    format: UBX
    started: true
    format: LLH
    started: true
  air rate: 2.6000000000000001
  frequency: 868000
  output power: 20.0
position output:
    baud_rate: 57600
    device: UART
    enabled: true
    format: NMEA
    io_type: serial
    baud_rate: 38400
    device: UART
    enabled: false
    format: ERB
    io_type: serial
rtk settings:
  elevation mask angle: 15
  glonass ar mode: 'off'
  gps ar mode: fix-and-hold
  max horizontal acceleration: 1.0
  max vertical acceleration: 1.0
  positioning mode: kinematic
  positioning systems:
    compass: false
    galileo: true
    glonass: false
    gps: true
    qzss: true
  snr mask: 35
  update rate: 5

From documentation, the maximum current drawn by the M2 is 3A@5V. That means 15W of power. Make sure your power source is capable of that. Some powerbanks just provide up to 2A in total, or sometimes only one port is supported for 3A.

Hello, thanks for the response.
As I tried to describe:
The whole product chain is from emlid (except the batteries which are high current ones), so my guess is, that the supported power by the Navio2 and the power module are designed such that the reach M2 should be working fine.

(Besides the fact that 3A exceeds the USB standard by a factor of 6…)

Hi @q-wertz,

Navio2 may in fact provide not enough power for Reach M2 to boot. Such unit’s behavior indicates that. That’s why we recommend powering Reach M2 separately. However, please, make sure the unit is not powered from several ports simultaneously.

Thanks for the information.
Would be good if this information makes it into the Docs

  1. ReachM2 to Navio over UART
  2. Information how much power the Navio2 can provide somewhere in the Navio2 docs


Thanks for pointing it out! We’ll think about how we can add this info to our docs.

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