OpenGD77 CPS Timeslot assigned to Digital Contacts

posted in: DMR, GD-77, HTML5 | 43

With the OpenGD77 firmware Talkgroups are assigned to Channels, and the VFO, using a Rx Group list, however on DMR MARC and DMR+ networks, different TalkGroups operate on different Timeslots.


There was initially a crash bug in this version. So I had to withdraw it.

I’ve now, hopefully fixed the bug and updated the Tier2 Latest version so that it can be downloaded.

———————————————– Original Article continues ————————————————-

To overcome the need to remember which TimeSlot is required for each TalkGroup / Digital Contact, I’ve now modified both the Community CPS and the OpenGD77 firmware, so that there is an option to assign a Timeslot to a Digital Contact.

By default Digital contacts will have the Channel TS/ Repeater Slot override disabled, so everyone’s existing codeplug will continue to operate as befor

However if a Repeater Slot (TS) override is selected; when the Digital contact is used by the OpenGD77 firmware e.g when selected in the VFO or a Channel, the Repeater Slot (TS) value associated with the TG will be applied to the Channel or VFO as an override to either the TS assigned to the Channel and will also override the manual TS change made by pressing the Star key

In instances where you are using different networks which require the same TG on different Timeslots, I have also modified the CPS to allow creation of multiple Digital Contacts with the same TG number.

For Example.
I need TG 505 on both TS1 and TS2. So I have created 2 Digital Contacts with the Call ID of 505, one called “TG 505 TS1”, which has the TS set to 1 and another called “TG 505 TS2” which has the TS set to 2.

For TG’s like 9, where they are general purpose and I may use them on either TS, I just have one Digital Contact, but the override setting is set to “Disabled” so that selecting this TG will not change the current TS on the Channel or VFO.

This feature has no effect on the official Radioddity firmware, because I use an part of the Digital Contact data structure which the official firmware does not use, and also I do not change the value in the default data unless the dropdown menu of changed, to either TS1 or TS2.

To use this feature, download the latest Community CPS installer e.g

And install the Tier2 Latest OpenGD77 firmware


I’ve had reports of the firmware constantly rebooting under some circumstances.

The problem seems to be something to do with the settings that the firmware stores in the EEPROM.

If this happens…

1. Turn off the radio.
2. Press and hold the Blue button on the side of the radio
3. Turn on the radio and wait for it to boot-up
4. Release the Blue button

The settings should now be reset and the radio should not keep rebooting.

43 Responses

  1. Janusz - SO5AJG

    After the last firmware and CPS changes, each time after changing the settings in the code plug and uploading the file the same problem occurs, the radio resets, you need to use the blue button when turning on and in addition you need to make the settings again in the menu – Display options, Utilites, because everything returns to the original settings.

  2. Janusz

    In addition, after turning off the radio and then turning it back on again, the problem appears again as at the beginning.

  3. Roger Clark


    I will investigate

  4. Roger Clark

    Blue button during reboot will reset all settings including display settings

  5. Ken, M1DYP

    thanks roger. no problems here

  6. Roger Clark

    I managed to replicate the problem by using someone else’s codeplug

    I remove replaced the Tier2 Latest file on the server with the previous version which should be stable

    Its too late now for me to start looking at the problem, but I’ll investigate it tomorrow as its related to the codeplug and possibly the data in the contacts

  7. Roger Clark

    Hi Ken

    It looks like only some codeplugs have the problem.

    My codeplug is OK, and it looks like your codeplug is also OK, but I tried a codeplug from W1RHS in the USA and his codeplug now crashes and reboots my radio as soon as I go to a channel.
    If I stay on the VFO I think its OK.

    I’ve removed the firmware version which was crashing and have re-instated the previous version.

    Its getting too late for me to investigate the problem today, but I’ll load the other codeplug into my development radio tomorrow and work out why its crashing.

  8. Ken, M1DYP

    thanks for the info. looks like i spoke too soon, I have same reboot problem so have reverted to yesterdays.

  9. Janusz

    On the occasion of problems with the latest firmware, I learned that via the blue button you can reset to factory settings, which I did not know before. As you can see, every situation also brings benefits.

  10. Janusz

    I have noticed for some time that when I select items in the menu, pressing the up or down button once, the cursor jumps to me by two items, but at first I did not pay attention to it.

  11. Roger Clark

    I already fixed that, but it was part of the versions which crashes

    I may release an interim version with those fixes and also the mic gain

  12. Roger Clark


    I screwed something up.

    I will probably release an interim version with the mic gain etc and then work out why the version with the TS stuff keeps crashing

  13. Roger Clark

    I added the feature to reset via the Blue button a few months ago, but forgot to announce it ;-(

  14. Matt Fairbairn (M6SEU)

    Don’t know if any help when i loaded new CPS with mic gain firmware some of the private id’s in the contacts list had the Time Slot already set mostly TS1 .
    Cheers Matt

  15. Roger Clark

    Hi Matt.

    I’ve emailed you an updated version

  16. Mike

    The ability to assign the TimeSlot to each talk group is a great idea, it saves having two channel entries for each repeater and two receive groups (one for each TimeSlot). I wonder, however, if it might be more flexible to set that option up in Receive Group window as opposed to the Digital Contact window if this is possible? The reason behind this thinking is that if you are using a talk group that has the same ID both on the Brandmeister, TGIF DMR MARC and DMR+ networks (there are a number of them) you will need to be able to assign them to different TimeSlots on different repeater networks. For example, Iowa (3119) may be on TS1 on a DMR+ repeater but could be on S2 on a TGIF repeater (just an example). By (if possible, to do) having the flexibility to set that option at the Receive Group window would be very helpful. Just a thought to be considered.

  17. Roger Clark

    Hi Mike

    I’ve emailed you the latest, bug fixed version which has this feature.

    Re: Same TG’s with different TS

    I had the same problem, so I modified the CPS to allow duplicate TG’s e.g. I have a TG called “TG 505 TS1” and also one called “TG 505 TS2”
    I have separate Rx Group lists for BM and DMR+ and assign the different TG505 contacts to each Rx group

    I think this gets around the problem of the different networks needing different TS for the same TG

    Also, you do not have to set it to override. If you leave the override set as Disabled, it takes the TimeSlot from the channel

  18. Ken, M1DYP

    hi Roger, all seems good thank you, very fast fix, kind regards

  19. Janusz

    Hi Roger,
    Battery charged, I can continue testing, but so far excellent. Many thanks for the quick action. The 1750Hz blue button also works very well.
    All the best.

  20. Janusz

    Is it possible to adjust the transmission power when working GD-77 as a hotspot from the level of pi-star dashboard. I would need a small power of 200-400mW.

  21. Antonello

    Hi Roger, I would like to know if it is planned to set different ID on the same radio (to use the walkie talkie both me and my brother with our different calls and ID). 73 de Antonello, iw3sip

  22. Roger Clark

    You can enter different IDs

    Press Function + # three times and enter the new temporary ID

  23. Roger Clark


    Power adjustment is supported in the normal way, I.e in the expert section.

    See the User Guide

  24. Janusz

    Hi, Roger
    The only thing I found in Pi-star is in the Expert tab and Info window is the Power item, which is currently set to 1 and how it relates to the power size, unless the transmission power is set elsewhere.

  25. Roger Clark


    100 = 100% power

    But in the OpenGD77 I had to ignore the value if it is 100 because it would result in the radio transmitting at 5W which is not sustainable .

    Most people do not even known there is a power percentage value in the expert settings and they do not change it.

    So if the value is 100, the radio uses the power setting from the Options screen.

    However any other value e.g. 50 = 50% will cause the output power to be 2.5W

  26. Janusz

    I noticed one more problem, namely I use Echo for testing and our number is 260097 and it must be sent as private, because as the TG comes out, but there is no response, while if I enter a private contact with ID, the strange number 15671721 can be seen on the dashboard and of course there is no connection.

  27. Roger Clark


    I didn’t try Private Digital Contacts

    Use direct entry for the ID use ## 260097 Green

  28. Janusz

    OK. That’s how I solved choosing private numbers on Echo. One more thing came to my mind. Is it possible to do so in CPS that in one of the tabs one can directly enter the update firmware and not run a separate firmware upload program. Certainly it would be more convenient as it is e.g. in AnyTone 878.

  29. Roger Clark


    Its on my To Do list to include firmware update in the CPS.

    I even looked at the files I would need to include into the CPS yesterday !

    I normally use my own firmware loader

    You can just associated the .SGL files with this exe, and then double click on them, or drag and drop onto it, or just run it and select the file.

  30. Janusz

    Thank you Roger and another step forward. When reducing this power, this parameter did not change as needed, but finally I obtained 253 mW. I like it more and more, because the radio works better and better.

  31. EA3BIL Rafa_RGB

    Hi Roger (and @ll the rest, of course…)

    You said:
    “Press Function + # three times and enter the new temporary ID”

    There’s a “trick” to also reach that point.

    Pressing twice # (we get PC entry), hold BLUE and press again #

    Here we go !!!


  32. EA3BIL Rafa_RGB


    About TG 15671721…

    It shows on my PiStar when I keyDown a channel with defined TG. i.e. 8, 214, 21460,…

    I’ve double checked channels definitions and they show their own and correct TG’s.

    You can have a look on the DashBoard at my website.
    The entry on 23:57:33 Nov 12th was my TX on TG8.

    What am I doing wrong ??


  33. Roger Clark

    I’m confused.

    Is this something to do with hotspot mode, or the CPS Timeslot feature in digital contacts?

  34. EA3BIL Rafa_RGB

    No, I’m using the GD77 on Tier 2 to access my HotSpot based on Pi3, DUAL HAT & PiStar 3.4.17

    I don’t know if this strange behaviour is linked to TS feature…

  35. EA3BIL Rafa_RGB

    This is the unique conversation where this “magic number” was mentioned.
    (As far as I saw)

  36. Roger Clark

    email me your website IP address

  37. EA3BIL Rafa_RGB

    I read the GD77 with the OpenGD77 Support option within the new CPS (firmware loader includer).

    I can eMail you all the data files in case you need to analize the data I’m using.

  38. Roger Clark

    You mean

    TG 15671721

    Are some of your contacts Private Calls ?

    I sent you an email about Catalan

    Send me your codeplug, I think it has some problems 😉

  39. Roger Clark

    See my email.

    The OpenGD77 does not work the same as the official firmware for Digital Contacts in the Channel

    You must assign a Rx Group to each DMR channel and it Must have at least 1 contact in the Rx group

    You only need 1 channel per frequency.

    You specify which TGs are for each frequency (channel) by putting them in an Rx Group and assigning that Rx Group to the channel

    Its documented in the User Guide document, but this is only in English

  40. EA3BIL Rafa_RGB

    Ok… My mistake.

    Working in translation of User Guide to ES and CAT aswell…

    Thanks for help!!!

  41. Roger Clark

    No worries

    I should all a backup system in the firmware, which handles old codeplug style, that don’t make use of the new way that the OpenGD77 simplifies the codeplug

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