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 Post subject: Raspberry Pi GPIO questions
PostPosted: Tue Mar 10, 2015 9:05 pm 
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Joined: Tue Mar 10, 2015 8:35 pm
Posts: 2
a) Is the GPIO numbering based on the header pin number or the SoC GPIO number? (I'm leaning towards SoC as old Pis have 26 header pins and you mentioned "Pinout on +/2 only").

b) Does the Pi version already support HVP? (yes, I'm aware of 3V3, 5V and 12V. 7805 and tran- and resistors to the rescue).


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 Post subject: Re: Raspberry Pi GPIO questions
PostPosted: Sat Mar 14, 2015 10:24 am 
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Joined: Fri Oct 28, 2011 5:18 pm
Posts: 225
Hi Horst,

the pin numbers in the config file pgmifcfg.xml are based on the SoC GPIO numbers.
E.g.:
GPIO5 would be pin 29 on the Raspberry Pi B+ 40 pin header
GPIO26 would be pin 37 on the Raspberry Pi B+ 40 pin header

But you can simply adjust the pins used in pgmifcfg.xml if you want to use other GPIOs.

Using PICPgm on the Raspberry Pi as HVP would work, if you adapt the programmer circuit accordingly.
From SW point of view it is exactly the same as the PC version of PICPgm.

HVP is controlled via MCLR pin, i.e. add a transistor to switch Vpp on the PICs MCLR pin, e.g. as the Tait parallel port programmer was doing it (http://picpgm.picprojects.net/hardware. ... PROGRAMMER).
For the other pins you need a level shifter which converts the 3.3V from the Raspberry Pi to the 5V of the PIC.
Unfortunately, I found no time to draw a circuit with all this features. Hope I can provide it soon.

Regards,
Christian


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 Post subject: Re: Raspberry Pi GPIO questions
PostPosted: Wed Mar 18, 2015 12:34 am 
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Joined: Tue Mar 10, 2015 8:35 pm
Posts: 2
Thanks Christian.

When I asked the questions I wasn't aware that pics use the same programming instruction set/algorithm no matter if LVP or HVP... I'll peek in the respective datasheets next time ;)

I've used the schematic from rpp (http://mujweb.cz/tlc/rpp/), 3 TUN 3 TUP and a handful of common resistors.

Worked like a charm.

Thanks for the RPi port.

Oh and btw: It's "Verifying", not "Verifing" ;)


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