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OpenGD77 Hotspot Raspberry Pi 3B+

Posted: Fri Sep 17, 2021 3:37 pm
by AB0LV
I heard about OpenGD77 last week. It seemed liked the perfect solution for the high powered hotspot I had been looking to build.

Yesterday I got my GD-77. None of the versions of CPS I tried would recognize the comm port. It appears under Human Interface Devices when the cable is plugged in. Once I figured out that I could load the firmware without that I didn't bother trying to figure out why.

It took a couple of hours to get everything worked out. The first time it keyed up the transmitter locked key down. I added three ferrites at each end of the USB cable and it is been running flawlessly ever since.

OpenGD77 Version: PublicBeta_20210914
Transmitter Power 2 watts
Raspberry Pi 3B+
Pi-Star 4.1.5
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Re: OpenGD77 Hotspot Raspberry Pi 3B+

Posted: Fri Sep 17, 2021 3:49 pm
by F1RMB
Hi,

For the OpenGD77 firmware, you need to use the OpenGD77CPS, available here
Reading or writing the codeplug has to be done when the transceiver is running in "normal" mode, not in bootloader mode, like when you flash a firmware.


Cheers.
---
Daniel

Re: OpenGD77 Hotspot Raspberry Pi 3B+

Posted: Fri Sep 17, 2021 4:49 pm
by AB0LV
Hi Daniel,

I tried the release version of the OpenGD77 CPS with the release version of OpenGD77 and couldn't see the comm port. I switched to the latest version of cps (OpenGD77CPSInstaller_E2021.09.14.01.exe) and the 9/14 beta of OpenGD77 to see if I could find the comm port. At that point I figured out that the OpenGD77 CPS didn't need to see the comm port to upload it's firmware and I just skipped backing up the EEPROM, flash and calibration. Since I had uninstalled the release version I just went ahead and loaded the beta version. Installation of the firmware was easy with no errors.

After reading your reply I tried backing up the EEPROM in normal start up mode and it didn't prompt me to find a comm port. If it prompts me to pick a comm port, I'm doing it wrong. :)

The hotspot mode in PublicBeta_20210914 is working flawlessly. I have it on talkgroup 3100 which sees a fair amount of activity and it hasn't missed a beat once I put the ferrites on the USB cable.

Thank you for the Hotspot Mode, it is such a great feature!

Lucian

Re: OpenGD77 Hotspot Raspberry Pi 3B+

Posted: Fri Sep 17, 2021 5:31 pm
by G4EML
If you purchased a new GD77 then it will have had the manufacturers firmware loaded. That doesn’t appear as a Com Port.

The Com port will only appear once you have loaded the OpenGD77 firmware.

So what you observed is perfectly normal.

Colin.

Re: OpenGD77 Hotspot Raspberry Pi 3B+

Posted: Fri Sep 17, 2021 6:59 pm
by F1RMB
Hi,

If you're running the OpenGD77 firmware, double check the drivers installed by the OpenGD77CPS.
Check you Windows device manager to see if it's COM is not in error (still drivers problem).

EDIT: I just re-read your latest post, so it's all working. Cool.


Cheers.
---
Daniel

Re: OpenGD77 Hotspot Raspberry Pi 3B+

Posted: Sat Sep 18, 2021 4:05 pm
by r2dze
Here is a build of hotspot based on Raspberry Pi 3B, Baofeng DM-1801 and 3G mobile modem i just finished, designed for long term full power operation and to be installed permanently into my car. There are English subtitles if it would be interesting to someone to watch :D .


youtu.be/bFrp7XXlAHI

Re: OpenGD77 Hotspot Raspberry Pi 3B+

Posted: Sat Sep 18, 2021 7:42 pm
by m1dyp
nice

Re: OpenGD77 Hotspot Raspberry Pi 3B+

Posted: Sat Sep 18, 2021 8:47 pm
by VK3KYY
Thanks for sharing.

There is also a post from over a year ago, a ham in Turkey made a 19 inch rack mount hotspot also using bare boards, of a GD77

Re: OpenGD77 Hotspot Raspberry Pi 3B+

Posted: Thu Nov 11, 2021 9:03 am
by R3DBU
Hi.
Where can I get a switching diagram (electrical diagram) to create an access point from a Baofeng DM-1801 radio?

Re: OpenGD77 Hotspot Raspberry Pi 3B+

Posted: Thu Nov 11, 2021 10:20 am
by VK3KYY
R3DBU wrote:
Thu Nov 11, 2021 9:03 am
Hi.
Where can I get a switching diagram (electrical diagram) to create an access point from a Baofeng DM-1801 radio?
Don't cross post