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Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia


Post by VK3KYY » Sun Nov 17, 2019 10:17 am

Q. Which radios does the OpenGD77 firmware work with.
A. Currently the firmware works with the Radioddity GD-77, Baofeng DM-1801 VERSION 1 ONLY (aka DM-860), DM-1801A, GD-77S and Beofeng RD-5R, and TYT MD-9600 / Retevis RT-90
Some features like Hotspot mode are not available on the RD-5R because of hardware limitations in that radio.

Q. Can the firmware be used commercially
A. No. The firmware license forbids any form of commerical use of the firmware binary or the source code.
Installing the firmware onto the radio will invalidate all FCC licences, and the same applies to all other licensing bodies.

The firmware is for Amateur Radio and private listening use only.

Q. Where can the firmware and source code be downloaded from.
A. See the latest released version downloads/releases/

Q. Is there a manual
A. https://github.com/LibreDMR/OpenGD77_UserGuide

English versions

View online: https://github.com/LibreDMR/OpenGD77_Us ... r_Guide.md

PDF version: https://github.com/LibreDMR/OpenGD77_Us ... _Guide.pdf
Chinese versions

View online: https://github.com/LibreDMR/OpenGD77_Us ... uide_CN.md

PDF version: https://github.com/LibreDMR/OpenGD77_Us ... ide_CN.pdf
Please note

Only the English version is maintained. The Chinese version is now considerably out of date

Q. If I install this firmware can I return to the official firmware
A. Yes. But only if you backup the Flash, EEPROM and MCU ROM data, using the OpenGD77CPS after installing the firmware, so the Flash memory can be restored prior to reinstalling the official firmware.

Q. How do I install the firmware
A. Either using the official Radioddity (or Baofeng) firmware installer program, or the firmware loader included in the release, or using the firmware loader in the OpenGD77CPS

Q. I installed the firmware but can't connect with the CPS
A. You need to use the OpenGD77 CPS, (including the USB driver needed for the OpenGD77) which can be downloaded from here

Q. Do I need to update my codeplug to use the firmware
A. Not on the GD-77 but you yes on the Baofeng DM-1801 and the MD-9600, because the Baofeng codeplug in the radio is in a different format.

To convert your DM-1801 codeplug to the OpenGD77 format, use the converter tools written by Colin G4EML
Export the DM-1801 to CSV files and import those files into the OpenGD77 converter and resave

For both all radios, the way the OpenGD77 firmware handles Channels and RxGroups is different from the official firmware.

The OpenGD77 firmware uses the Rx Group list as a "Talkgroup list" for both the Rx and also the TX, so it is not necessary to duplicate the same frequency for every TG that you use on that frequency.
Just put all the TGs for the frequency (e.g, for a repeater) into a Rx Group list e.g. "DMR+ AU" and assign that Rx Group list to the repeaters that use that group of TGs
You can then cycle through that list, on the channel screen, by pressing the Left or Right arrows
The Community CPS also allows a TimeSlot to be assigned to a Digital Contact / TG, as an override to the TS (Repeater slot) for the Channel, so there is no need to create separate channels for TS1 and TS2.
Additionally, the TG number can be manually entered via the keypad (by pressing # TG_NUMBER then Green button)

The OpenGD77 also has a fully functional VFO with separate Tx and Rx frequencies so the radio can be used even if no channels are defined.

Even the user's own DMR ID can be entered via the keypad, so the GD-77 can be used even if the default codeplug that is installed by Radioddity is in the radio.

Q. Is there a tool to Export and Import the codeplug to and from CSV
A. See https://www.gb3gf.co.uk/downloads.html where Colin G4EML has some great utilities including a codeplug tool which supports the 80 channels per zone now available in the OpenGD77 firmware

Q. A feature in the Official firmware is not in the OpenGD77 firmware
A. This is not a complete replacement for the official Radioddity or Baofeng firmware. It will never be identical to the official firmware as that would be a complete waste of time ;-)
The firmware is designed for Amateur Radio use, and the license forbids use by commercial users. Also the firmware will invalidate the FCC compliance of the radio.
The firmware is still under development with new features being added constantly, with the eventual goal of implementing all functions needed for Amateur radio use.

Q. The radio won't turn or has other problems
A. Try these steps until one of them hopefully fixes the problem.

1. Check the battery is not flat, using a volt meter. Charge if necessary.
2. Remove and re-insert the battery, and try turning on the radio again
3. Remove and re-insert the battery and then hold in button SK2 and turn on the radio
3. Remove and re-insert the battery and then hold in buttons SK1 and SK2 and turn on the radio.
The radio should enter the bootloader, and the green LED will illuminate.
If the radio enters the bootloader, reload the firmware using the CPS.

Note. Do not transmit any RF from other radios while reloading the firmware, becasue this can corrupt the firmware data being sent via the USB cable.

If the radio won't even enter the bootloader, and the green LED does not illuminate, the radio probably has a hardware fault, or perhaps the MCU / CPU program ROM has been completely erased or corrupted.

It is possible to reload the MCU ROM via a hardware debugger dongle, e.g. JLink Edu, but this requires opening the radio and attaching 5 wires to test points on the PCB. It also requires a programmer dongle.

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