RS2 (and maybe RS+) firmware flashing issues

I apologize for the new thread but this needs it’s own thread. While other threads mention firmware flashing issues, they have non-related topic names (bluetooth), or they seem specific to RS+. A new topic can put these in one place, so maybe we can experiment with work-arounds until a formal Emlid fix is ready.

Two threads mention reflashing errors…


but would it be possible to have one topic so we can help each other with a similar problem?

I have an additional clue/idea which may help provide a workaround of trying a different computer and/or fully charging a unit may help:

Bryce in the second link above could not get his firmware flashed, with an error that the flasher could not find eMMC module.
I took the same receiver, and after charging it up well, managed to reflash the receiver on a computer of mine, but during the reflashing procedure my computer showed repeated warning messages that the device on the USB port was requiring more power than available (see image) and repeatedly made these error/warning messages.

I kept ignoring these error messages, and my computer managed to flash the RS2, but is it possible that the larger than normal power drain (1000-1500 mA instead of the usual 500 mA limit on some USB ports) is causing firmware programming to fail?

If anyone is having trouble reflashing RS2 (or even RS+) firmware, and getting an error of not being able to find eMMC, try fully charging with a high power charger (5-10 amp) for a while, and try a different, maybe newer, computer, and report back if it’s working. It may have worked for me.

(I think the RS+ limited charging current to 500 mA, which caused some slow charging complaints, but think the RS2 was specifically designed to allow high power charging. The docs suggest 5, 7.5 or up to 10 watt chargers. Could that be causing some USB ports to fail during firmware reflashing?)

  • tj.

We’re you on USB 2.0 or 3.0? I have seen the same message when connecting some of our diagnostics equipment in 2.0.

Good question, I succeeded in firmware reflashing on a Dell laptop that specifies it’s a “USB 3.1 Generation 1 port, with 5 Gbps speed.” I can’t seem to find a reliable specification as to maximum power output. Maybe 900 mA? Maybe up to 1.5 amps? I wish I had one of those little USB power monitors, but don’t know how accurate they are with transcient or pulse currents. I have no idea what sort of port was used by those who could not get reflashing to work. Possibly a USB cable could be made to disconnect the 5 volt power lines, so the RS2 doesn’t try to draw too much current while reflashing.

Again, this may not be the reason the firmware reflashing fails for some and not others. But the current draw could be a possibility.

Reach RS2 is compliant to the USB-C spec. It will only draw what is allowed by the upstream cable/adapter/port. That upstream apparatus signals to the RS2 what it is allowed to draw.

That said, if you happen to get your hands on a counterfeit USB apparatus, then all bets are off.


Hi @tejones777,

Thanks for the report and contribution!

The issue with flasher is barely connected with power supply, I’m afraid.

We’re working on new flasher now, and I’ll inform you once it’s available.


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