RFD900x Integration


I am trying to integrate both an Emlid LoRa (Port S2) and an RFD900x (Port S1) onto a Reach M2. I have used the LoRa radio many times and all works well, but when I connect the RFD900x, the RFD900x doesn’t come on and the LoRa radio power lights starts blinking weakly. When I look at the power going into the RFD900x, it shows it is pulling the voltage down to 1.4 V. As soon as I remove the RFD900x the LoRa radio goes back in operation.

I am powering the M2 with a 3A USB power supply, so I thought I had enough power. I tried the RFD900x directly on a USB port on a laptop and it seems to work fine.

Any thoughts? Do I need to figure out a way to power the RFD900x separately? How much current does the M2 pull in general? How about the LoRa radio?


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Hi Keith,

A power supply may indeed be the source of the issue in your case. On the Reach M2 JST-GH or USB port, the voltage should be in the range of 4.75 - 5.5V. Please also note that the RFD can consume up to 800mA in peak, so make sure that your power source can provide enough power for both the Reach and the RFD900. Can you connect only RFD900x radio, without LoRa, and let me know if it works?

Can you also explain your desired workflow? Emlid Flow only supports 1 correction output/input option at a time. Why do you want to work with 2 radios at the same time?

Hi Olesia,

The RFD900x works fine with a separate power supply, and I was able to see NMEA and ESB streaming over it successfully. Disconnecting the LoRa doesn’t allow the RFD900x to be powered via the JST-GH still.

My layout is that corrections are coming from the base station via LoRa and the RTK position is coming back to a completely separate system via the RF900x. It seems I can configure correction input on the LoRa and stream position out on the RFD900x. Will that not work? The good thing is the RFD900x will only be an output stream from the M2…nothing coming back.



The fact that the setup works well with additional power to the RFD900x suggests that the issue is with the power supply to the radio in the original setup.

You can stream the position from the RFD900x. Just select Serial in the Position Streaming setting.

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