serial wrote: ↑
Mon Feb 19, 2018 9:22 am
Thank you for your comment.
The I2C device is PIC microcontroller.
O.K. If said "PIC microcontroller" requires "clock stretching" to be supported (by the "I2C master", ie. the Pi) then the Pi can't do that**, IIRC. AFAICT things "just work" with most of the common I2C expander, LED matrix/keypad scanner I.C.'s etc.****
** AIUI, there is/was some limited support via a "bit-banged" driver but none in the "kernel driver".
**** Quite a few example circuits within my webpages. NB: some of the devices run a 5V so work best with 3.3V - 5V level shifters interposed but it is possible to drop the device's Vcc to 4.4V and then the Pi's 3.3V is responded to as a logic high level: http://www.cpmspectrepi.uk/raspberry_pi ... iPlus.html
Still running Raspbian Jessie on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W) but Stretch on my P3B+, P3B, B+, A+ and a B2. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm