The OpenGD77 Tier 2 (Alpha version) firmware seems to now be stable enough that I can make it publicly available for other early adopters to test.
I’d like to thank all of the testers including Clayton VK7ZCR, Rick W1HRS and Jon G4TSN for installing and testing the numerous prototype versions which I have been creating over the last 2 or 3 weeks.
The Alpha version can currently be downloaded from
I will remove this version later when there is a Beta version and when finally there is a fully released version
Important notes about this version
- This version does not have Hotspot mode
If you want to use Hotspot mode, install the Tier 1 version. (See links in my previous posts)
I will not be able to get Hotspot mode working until the Tier 2 version is fully stable. - This is Alpha version software, it still has some quirks and possibly some bugs.
These include the following :-1. DMR ID’s are enabled for both timeslots, regardless of which timeslot you are listening to. This means in the middle of an over you may see another ID appear, which will be another station using the other timeslot.
I hope to eventually be able to resolve this problem, but at the moment I can’t find a way of knowing which ID is for which timeslot, when the data is sent from the C6000 DMR DSP chip.
2. Your own DMR ID may appear when you release the PTT. I’m not sure why this is happening. The C6000 ID / TG data memory seems to sometimes contain your own ID just after releasing the PTT, but not always, as if the repeater was echoing back your own ID sometimes.
3. Parrot calls to #9990 can sometimes be interpreted as private calls to your ID. I’m not sure why this wasn’t an issue in the Tier 1 version, but its more noticable in the Tier 2 version. - There have been some changes to the user Interface functionality.
I have not had time to update the Tier 1 documentation to reflect these changes.1. The Star (*) key now toggles the timeslot (TS1 to TS2 and then back to TS1 etc)
2. To switch between DMR and FM mode, you now need to use Function + STAR key
3. A new feature has been added, to both the Tier1 and this Tier2 version, to change Zones by pressing Function + Up or Function + Down on the Channel screen.
4. PA drive values can now be set as high as the maximum value that the hardware will allow (the value is 4095 , as the hardware uses a 12 bit DAC)
This will allow power output of more than 5W on some radios, depending on frequency and the efficiency of your PA, but running more power than the manufacturer’s specification may damage your PA.
5. PA drive value can be changed in steps of 10 for fine tuning of power e.g. when testing the minimum required power to access a repeater.
By pressing Function + Left or Function + Right - Repeater wake-up retries are currently unlimited. The firmware will retry every 500mS until you release the PTT or until it has activated the repeater.
While the firmware is attempting to activate the repeater the Talk Timer will not change. It will only start counting once the repeater becomes active. - Please make sure your codeplug assigns a valid Rx Group to each repeater channel, because the OpenGD77 firmware uses the Rx Group as a list of Talkgroups for each channel.
I you have not assigned a Rx Group. e.g. its set to None or its empty you will get strange results. - Although its been tested my multiple people for over 2 weeks, using the Motorola DR3000, MMDVM and Hytera repeaters as well as duplex and simplex Pistar MMDVM hotspots. On both VHF and UHF, I’m sure some people will find bugs which we have not encountered already.If you can’t access your local repeater or your duplex hotspot, please double check your codeplug settings, including the ColourCode and and Rx Group list etc. Because its more likely to be a codeplug problem than a firmware problem.
If you find any bugs which I have not listed, please feel free to post a comment, and I will try to investigate the bug when I have time.