Emlid Reach M+ Power Issue

Hello to everyone

I am working on mapping with Emlid reach m+ and DJI Phantom 4. I trigger my Emlid device via the LED on the Phantom 4’s arm. However, on this flight, the device suddenly shut down while operating normally and only the orange power light remained on. I don’t understand what the problem is? Here is the log file of the device

Did it go orange in the middle of a session of normal operations or did it only boot to orange and not go beyond that? I have had most of our M+ and M2 receivers at some point hang on orange and in some occasions it was not getting enough acceptable satellite signals and on other occasions I think it was a power glitch. I have learned that I cannot rely on them booting correctly when indoors even if I am at a south facing window and sometimes I need to connect it to a fast-charge phone charger in order to “jump-start” it. I don’t know if this really does anything and obviously my previous method of powering works for a time, but if I can get it to boot correctly off of a good phone charger the normal power method usually starts working again.

Thank you for your answer.

I have made 5 flights with the Phantom 4. There was no problem in the first 2 flights, but in other flights, when I turned off the embankment and turned it back on, all the lights turned on properly, but within 1-2 minutes it turned orange again. I am using a powerbank with a 5v output to power the Emlid

When I look at solid flight data, I see a lot of interruptions, is this normal?

I see 8 good GPS and 3 good GLONASS with a 4-minute stoppage in the middle. Was this a battery swap?

Yes, there was a battery change in 4 minutes.

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Thought so… and on the small gaps in the stream of the “good” satellites that is normal. If you PPK I would try with and without GLONASS to see the difference in fix you get.

As for the power issue I am sure someone from Emlid will come by and take a look at your report. I really don’t see any interruptions in the stream that would be a result of a power interruption.

There was one more thing on my mind. I do the triggering event with the led lights on. Since the forward overlap is 80%, it triggers too often. Is frequent triggering like this a problem for emlid reach m?

Hi İzgi,

Welcome to our community!

As Michael noticed, the logs recorded by the receiver stop in case of power interruptions. However, as I can see, the log is continuous, and the time marks were collected during the whole flight except for the battery change period. I’ll discuss your case with the team and get back to you soon.

Hi Izgi,

Frequent triggering shouldn’t affect Reach M+ performance this way. In most cases, the red LED only turns on if there are any issues with the power supply. To check it, please tell me if the blue and green LEDs turn off when you connect Reach to a stable power supply such as a PC or a wall adapter.

As I see, the raw data log from the device contains a lot of cycle slips. They can appear at the moment when the signal is delayed or disrupted:

Since the signals were tracked without cycle slips while you changed the battery, it looks like the reception of the GNSS signals was affected by the RF noise from other electronics. Could you please share some photos of your hardware setup? It will help check what might be wrong.

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I have seen this kind of issue before when using near high voltage power lines and radio towers. I always try and stay away from these. The data after the power swap looks just like radio interference.

I was on the side of a county secondary road about two years ago and a county sheriff came by and asked what I was surveying. While the unit was logging data, a call on the sheriff’s radio came in and he responded to the dispatch a couple of times. When I got back in the office and downloaded the data to PP, I could see the cycle slips where the sheriff was responding to the dispatch. Sure enough, there was about three areas in a 5 minute window of the file where he responded with his radio ! His car was probably about 10 feet from the receiver. Good example of radio interference.


I have seen similar issues around high-voltage facilities and broadcast radio antennas but we had a really strange one in an area that always had GLONASS issues. The spot that we selected for the base was being interfered with what looked like a HAM antenna, also where I fly from. We moved the base to the other side of the site and no more issues.

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Hello again.

I had the opportunity to do a few more tests and although I supplied electricity via the emlid reach m+ powerbank, the electricity was cut off after flying for a few minutes in the air. All the lights on the emlid go out.

Could it be possible that I’ve connected the wrong cable to Port C1? I’m using GND-TimeMark1-5V pins on Port C1 in my current wiring. Would it be enough to just use the GND-TimeMark1 pins?

Sorry for my bad english :slight_smile:

Hi İzgi,

You need to use the Time mark1 pin and GND pin for integration with the Reach device. Since you supply power to Reach from the other port, you don’t need to use the 5V pin on the C1 port.

2 posts were split to a new topic: Cycle Slips Issue

The issue was resolved by changing the power supply. For more details, check the following post.