[Lazarus] FPC interface for reading I2C devices on Raspberry Pi?

[Michael Van Canneyt]

On Tue, 12 Nov 2019, Bo Berglund via lazarus wrote:

> On Tue, 12 Nov 2019 10:11:49 +0100, Bo Berglund via lazarus
> <lazarus at lists.lazarus-ide.org> wrote:
>
>> I would like to be able to communicate on the I2C bus from my
>> FPC/Lazarus programs on Raspberry Pi.
>>
>> There are at least two cases:
>> 1) Reading devices like RTC chips and other sensors.
>> 2) Reading/writing data stored in EEPROM chips
>>
>> Since the Raspbian system is a Debian Linux derivative I am hoping
>> there could be a simple way using file I/O, but I don't know how...
>>
>> Any suggestions?
>> Software to install in Raspbian?
>> Packages to install in Lazarus?
>>
>> I am already using the GPIO I/O via the PiGpio unit and it works well
>> to read and write I/O pins...
>
> After consulting with the Lazarus Forum I got some suggestions and now
> I have found a unit TMSLCLRaspiHW.pas from TMS Software, which
> implements I2C operations on Raspberry Pi.
>
> But it uses this setting:
>
> {$mode delphi}
>
> whereas my existing application files use this setting:
>
> {$mode objfpc}{$H+}
>
> Can these settings be mixed among units in the same application or
> does it have to be a common setting amongst all units?

It can be mixed. The setting applies to the unit in which it was found,
other units can have another setting.

Michael.