Author Topic: EEVblog 121GW Multimeter Issues  (Read 162251 times)

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Offline EEVblog

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Re: EEVblog 121GW Multimeter Issues
« Reply #1000 on: October 08, 2019, 11:15:47 pm »
if this multimeter's firmware is truly open source, i believe it will sell like hot cakes...
It was never open source or intended to be. The Bluetooth is a different matter.
That was the original hope, but UEi have said they will not allow this as it contains proprietary code used on others products etc.

I wonder, would it be possible to have the internal hardware interfaces documented so that a completely independent firmware might be written?

It's not just the hardware, it's the firmware bootloader + all the intricacies of how the calibration data is handled. Sure you could write your own firmware from scratch but then you'd have to recalibrate the meter, a job which most people do not have the equipment for + you need the programmer if you want to change the bootloader.
This has been discussed before. Given that UEi don't wan to release that stuff, it's just not worth the effort for the few people that would have the capability to do this. Maybe someone could reverse how the calibration is done etc, and figure out the bootloader, but it's tough ask.
« Last Edit: October 08, 2019, 11:18:41 pm by EEVblog »
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Offline exe

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Re: EEVblog 121GW Multimeter Issues
« Reply #1001 on: October 09, 2019, 08:22:52 am »
Somebody already posted a python script that decodes calibration data. I think the decoded data showed just a two-point calibration, no fancy "ADC curvature compensation" or anything else sophisticated. So, as far as I remember, it's perfectly possible to use original calibration data in custom firmware.

Offline firewalker

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Re: EEVblog 121GW Multimeter Issues
« Reply #1002 on: October 09, 2019, 09:24:52 am »
And someone posted code that can write to the screen.

« Last Edit: October 09, 2019, 09:37:54 am by firewalker »
Become a realist, stay a dreamer.

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