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OpenGD77 Hotspot PiStar update

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The configuration screen having a new Modem option of OpenGD77 DMR hotspot (USB)

 

And the Dashboard now displays the name and the firmware version

 

A note to the Beta testers.

 

Your versions won’t display the version number correctly, as I only added this today and I have not send out an update with the version number included.

I’ve been making some enhancements to Hotspot mode today, so that the display on the GD77 uses the DMR ID database to look up the callsign and name, for both Rx and Tx functionality

 

I’m also working to add power control via PiStar, but for that to work, I also need to add the general functionality to read the High and Low power PA drive values from the calibration data in the Flash memory and also build a look-up table to convert from required power values in milliWatts to PA drive values.

Because as you can see from the graph below, the relationship between PA drive level (voltage) and power output in mW is not linear.

 

The blue line in the graph, is record values from VK4JWT’s radio on 437.5 and the green line was my attempt to calculate the value using a quadratic equation.

However, I think its going to be easier to manually build a look-up table an interpolate between values

 

One other thing I noticed is that the power calibration on my radios is not that accurate. One radio was putting out 4.6W when it should have been 5W, so I’m not sure if the factory power calibration values are that accurate.

 


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