On Sun, 2 Apr 2023 07:31:43 +0200, Christo Crause via fpc-pascal <fpc-pascal@lists.freepascal.org> wrote:
>On Sat, Apr 1, 2023 at 9:57?PM Bo Berglund via fpc-pascal < >fpc-pascal@lists.freepascal.org> wrote: > >> Question: >> Can I use Linux file system commands to read/write the data on the i2c >> EEPROM >> memory device and if so how from fpc? >> > >To some extent it is possible to handle i2c transactions as file read/write >operations, but some ioctl calls are required to configure e.g. the device >address [1]. Take note that only a subset of i2c functionality is available >using read/write calls. Lazi2cdev [2] uses this approach. > >For finer control over the i2c transactions (for example combined >write/read transactions) low level ioctl calls are available in Linux. I >wrote an i2c class [3] using this approach. > >1. https://www.kernel.org/doc/html/latest/i2c/dev-interface.html >2. https://github.com/laz2wiringpi/lazI2cdev/blob/master/i2cdev_base.pas >3. https://github.com/ccrause/rpiplc_pas/blob/main/native/i2c.pas Hello again! I have now tested the two demos in github [3] and they seem to work OK. The i2cscan works and shows exactly the same as sudo i2cdetect -y 1 does from the i2c-tools package I installed via apt. i2c_read_reg works too inasmuch as it does not error out, but it returns FF whatever addres I read like the i2c-tools command does. I am not sure that it is correct though, for that I need to create an i2c_write demo app first so I can write values at different locations and read them back. The EEPROM has until now not been used so it is in its factory state with no data. Is there a reason that there is no i2c_write_reg demo in the github package? I will try to write one so I can test that as well... -- Bo Berglund Developer in Sweden _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
