Experimental version with option to disable CC filtering
Posted: Sat Feb 22, 2020 1:01 am
Thanks to some research from Colin G4EML, we have been able to disable the Colour Code filtering inside the HR-C6000 DMR chip
I've modified the DMR filtering in the options, so that the list is now
NONE
CC
CC,TS
CC,TS,TG
CC,TG,Ct
when CC filtering is disabled, the Colour Code display e.g C1 is shown in inverse video
Notes.
When CC filtering is disabled, occasionally there are some DMR noises at the end of the received signal.
I'm not sure if it will be possible to get rid of these, because the datasheet for the C6000 chip seems to say that CC filtering is always enabled and the received signal is also checked my the software to ensure the correct Colour Code has been received.
I'm not sure how , with the CC filtering enabled inside the C6000 that it could output data that was on a different CC, but I suspect there may be a design flaw in the chip, which can allow this to happen under some circumstances, hence the data sheet says the CC should be checked by the CPU.
Also.
There is no shortcut to change the radio to the Rx signal CC.
So if CC filtering is disabled, you may transmit on a different CC to the Rx CC, even though you can clearly hear the signal
I think possibly we may be able to speed up the CC scan function, by briefly disabling the CC filtering and then checking the received CC over several frames and then calculate which is the most likely CC for the Rx signal to be using.
I don't think we can simply use the first CC on the Rx signal in this case, as the received CC value may not be 100% accurate when the CC filtering is disabled.
Edit.
I've uploaded a slightly improved version of the CC filter, using a change supplied by Colin.
This is just a temporary fix, I need to completely review call acceptance criteria in the code to fix the ID display problem etc
I've modified the DMR filtering in the options, so that the list is now
NONE
CC
CC,TS
CC,TS,TG
CC,TG,Ct
when CC filtering is disabled, the Colour Code display e.g C1 is shown in inverse video
Notes.
When CC filtering is disabled, occasionally there are some DMR noises at the end of the received signal.
I'm not sure if it will be possible to get rid of these, because the datasheet for the C6000 chip seems to say that CC filtering is always enabled and the received signal is also checked my the software to ensure the correct Colour Code has been received.
I'm not sure how , with the CC filtering enabled inside the C6000 that it could output data that was on a different CC, but I suspect there may be a design flaw in the chip, which can allow this to happen under some circumstances, hence the data sheet says the CC should be checked by the CPU.
Also.
There is no shortcut to change the radio to the Rx signal CC.
So if CC filtering is disabled, you may transmit on a different CC to the Rx CC, even though you can clearly hear the signal
I think possibly we may be able to speed up the CC scan function, by briefly disabling the CC filtering and then checking the received CC over several frames and then calculate which is the most likely CC for the Rx signal to be using.
I don't think we can simply use the first CC on the Rx signal in this case, as the received CC value may not be 100% accurate when the CC filtering is disabled.
Edit.
I've uploaded a slightly improved version of the CC filter, using a change supplied by Colin.
This is just a temporary fix, I need to completely review call acceptance criteria in the code to fix the ID display problem etc