OpenGD77 Hotspot mode general Beta release

I think the OpenGD77 Hotspot mode firmware is probably stable enough for more people to Beta test it, so I am making it publicly available for download via this link on my blog

OpenGD77_20190906_Hotspot.0.0.2

This firmware can be loaded onto the GD77 using the official firmware loader. (after you extract it from the Zip file)

Please Note.

1. This firmware is still in the early stages of development.
2. You use it at your own risk.
3. It may not be completely stable and is likely to have bugs.
4. Using high power settings may overheat the PA in the radio, because the radio is not designed to be constantly transmitting.

Default power in the OpenGD77 firmware is approximately 1W, and this is the value that will be used by the Hotspot unless you change either the Power (PA drive) value in the Utilities menu, or you change the RF Level setting in PiStar’s Expert -> MMDVMHost settings.

If you change the power setting in PiStar to any other value apart from the default value of 100%, the firmware will use the value from PiStar.

Hence 99% will give almost 5W, which is unsustainable over a long period of time.

0% will almost turn the PA off completely, but you will find at short distances that the 5mW produced by the AT-1846S  Tx/Rx chip in the GD-77 can still be received.

The power display in Hotspot mode, is currently only a rough approximation of power, as its actually the percentage of PA drive, multiplied by 5000mW to give a mW figure.

However since the PA output is non linear with respect to PA drive voltage this value is not accurate.

If you want to set your Hotspot to a specific power level, which you measure using your own power meter.

1. Turn off PiStar (Power off)
2. Exit from Hotspot mode using the red menu key.
3. The radio will probably now be in VFO mode.
4. Connect a power meter
5. Press the * button and look at the top left of the display to confirm the radio is in FM mode (or press * again until you toggle into FM mode)
6. Go into the Utilities menu, and select a PA drive setting (approx 1700 gives 1W)
7. Adjust the value by pressing the left and right buttons.
8. Press the PTT to transmit in FM and confirm the power level
9. When you are happy with the power level. Press the green menu key.
10. Turn the GD77 off and on again, go back into the Utilities menu and confirm the power setting has been saved
11. Exit back to the VFO (or Channel screen) by pressing the green menu key.
12. Turn PiStar back on, and wait for the radio to enter Hotspot mode.
13. Make sure the RF level is set to 100%, as this will use the value you just assigned in the radio