On Sun, 02 Apr 2023 23:21:38 +0200, Bo Berglund via fpc-pascal <fpc-pascal@lists.freepascal.org> wrote:
>On Sun, 2 Apr 2023 23:14:25 +0200, Christo Crause via fpc-pascal ><fpc-pascal@lists.freepascal.org> wrote: > >>On Sun, Apr 2, 2023 at 9:30?PM Bo Berglund via fpc-pascal < >>fpc-pascal@lists.freepascal.org> wrote: >> >>> Is there a reason that there is no i2c_write_reg demo in the github >>> package? >>> >> >>I haven't gotten round to that, waiting for hardware to test the code with. >> >>I will try to write one so I can test that as well... >>> >>Would be nice if you could share that :-) > >Sure, I will probably continue with this tomorrow (I'm in Europe so it is soon >midnight here...). > >If I get it going I will post it or else I will ask about it here. > >My hardware is ready and operational, in fact my board also has another EEPROM >(same type) sitting on the i2c-0 bus prepared for being used as a HAT EEPROM. >Haven't gotten that far on the HAT handling though so it is totally unused. So now I have created a new class TI2c_eeprom, that uses the i2c.pas file to do the actual i2c handling. In this class I have tested the read and write functionality and I have the following findings: 1) The read works just fine for what I have done so far. 2) But I have problems with the write functions for multiple data I use the method: i2cMaster.WriteBytesToReg(i2caddress: byte; regAddress: uint16; data: PByte; size: byte): boolean;) With data specified as follows in the call: if not i2cMaster.WriteBytesToReg(FEEPROMAddr, startaddress, @source[0], NumBytes) then Here the source argument is a TBytes array of bytes so I supply the address of element 0 as the data argument (expected to be a PByte). When I step through this in the debugger and get into the method itself I can see that the source argument contains the data I have loaded into it, so the data is there. When I run that method to the end and it finishes without error, I still cannot see the data in the EEPROM at the given address. So for testing I changed the call to be: if not i2cMaster.WriteByteToReg(FEEPROMAddr, startaddress, source[0]) then This uses the method to write a single byte to the i2c device and it works just fine! So either there is a problem with the WriteBytesToReg() method or else my use of it... What comes to mind is the data type PByte, which I have never used before and do not know if it is valid. I am keeping the data in a dynamic array of bytes (the pascal type TBytes) and send the address of element 0 of that array as the argument to the method. Is this wrong? If so what should I use instead? Can I typecast it like this: if not i2cMaster.WriteBytesToReg(FEEPROMAddr, startaddress, PByte(source), NumBytes) then (Tried it and it does not work) ???? Seems like I am getting close but missing something important... -- Bo Berglund Developer in Sweden _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
