Using GD-77 with a PiStar hotspot

[AB6B]

I'm just starting out on the DMR journey and thought I'd try the Open GD-77 route. A few quick questions please:

1. How do I test that my GD-77 is working OK before I install the Open GD-77 firmware?
2. Do I need a special version of the PiStar software installed on my Pi Zero 2 W-based hotspot to run DMR with an Open GD-77 radio?
3. What does hotspot mode do?

Thanks in advance.

Ted

[kt4lh]

I wouldn't worry about testing it, you can always revert. You don't need any special version of Pi-Star, it's been directly supported for at least a year, so just latest release version is perfectly fine.

Hotspot mode lets you use another DMR radio to use your Hotspot basically like a local repeater that you control. But just to be clear here; you can use the GD77 as a normal radio with a normal hotspot.. Or you can put the GD77 in hotspot mode and then IT is the radio and Pi-Star just controls it. It makes for a much, MUCH better receiver, and of course higher output power as well (but watch your temps, really best to not exceed 2W of output).

[AB6B]

Thanks, you made that really clear. The detailed instructions for Open GD-77 also seem to make it clear that I can jump straight in and install Open GD-77 firmware on my GD-77 (when it gets here) using the Open GD-77 version of CPS and then backup the flash so I can revert to original firmware if it needs to go back.

[AB6B]

I don't have my GD-77 or my hotspot yet but they are on the way. I'm researching how to set up my GD-77 and have a couple of noob questions:
1. The FAQ says

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.

But it seems odd that I would back up the original firmware after I install the new Open GD77 firmware; is this right? I think it's saying:
a. Using OpenGD77CPS, install latest firmware to GD77
b. Backup the Flash, EEPROM and MCU ROM data, using the OpenGD77CPS (I assume this is somewhere in the CPS interface?)

Also, in building a codeplug, it looks like I would need to select a (limited) number of talkgroups that the radio will then scan and these go into my codeplug but:
2. How do I know what TGs to start with?
3. Is there a USA codeplug that I can use as a template?
4. If not, where can I get a list that I can pick from?
5. What happens if I have more TGs than will fit in my GD-77?
6. Do I need different TGs for use with local repeaters vs use with my PiStar hotspot?

Maybe there's an article on this that someone can point me to?

Thanks in advance.

Ted

[VK3KYY]

It does not say it backs up the official firmware.

The firmware is not in the Flash or EEOROM. They contain data

The MCU ROM needs to be backed up because it contains the hardware lock bytes specific to each radio and also the boot loader
MCU ROM may need to be installed using a hardware programmer dongle