I2C/IIC working on RPI4 8GB?

[Mark Murray]

On 28 Apr 2021, at 22:07, Mark Murray <markm at FreeBSD.org> wrote:
> 
> On 28 Apr 2021, at 09:19, Emmanuel Vadot <manu at bidouilliste.com> wrote:
> 
>> According to this document is this just to detect that the slave hold
>> the scl line too long so I don't think that this is the problem here.
>> If you have a scope or a logic analyzer I suggest you start by using
>> it to confirm that when you scan with i2c -s you see something.
> 
> As it turns out, my logic analyser arrived today.

I got an oscilloscope onto pins 3 and 5 (GPIO2 and GPIO3), and "i2c -s" does not a jot on them.

I don't know if this helps, but the gpioctl utility thinks the pins are both inputs:

[root at grasshopper ~]# gpioctl -f /dev/gpioc0 -l -v
pin 00:	1	pin 0<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 01:	1	pin 1<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 02:	1	pin 2<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 03:	1	pin 3<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 04:	1	pin 4<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 05:	1	pin 5<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 06:	1	pin 6<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 07:	0	pin 7<OUT>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 08:	0	pin 8<OUT>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 09:	0	pin 9<>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 10:	0	pin 10<>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 11:	0	pin 11<>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 12:	0	pin 12<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 13:	0	pin 13<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 14:	1	pin 14<>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 15:	1	pin 15<>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 16:	0	pin 16<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 17:	0	pin 17<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 18:	0	pin 18<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 19:	0	pin 19<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 20:	0	pin 20<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 21:	0	pin 21<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 22:	0	pin 22<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 23:	0	pin 23<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 24:	0	pin 24<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 25:	0	pin 25<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 26:	0	pin 26<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 27:	0	pin 27<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 28:	1	pin 28<>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 29:	0	pin 29<>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 30:	1	pin 30<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 31:	1	pin 31<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 32:	0	pin 32<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 33:	0	pin 33<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 34:	1	pin 34<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 35:	1	pin 35<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 36:	1	pin 36<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 37:	1	pin 37<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 38:	1	pin 38<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 39:	1	pin 39<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 40:	0	pin 40<>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 41:	0	pin 41<>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 42:	0	pin 42<OUT>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 43:	1	pin 43<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 44:	1	pin 44<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 45:	1	pin 45<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 46:	0	pin 46<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 47:	0	pin 47<IN>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 48:	0	pin 48<>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 49:	0	pin 49<PU>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 50:	0	pin 50<PU>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 51:	0	pin 51<PU>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 52:	0	pin 52<PU>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>
pin 53:	0	pin 53<PU>, caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB>

M
--
Mark R V Murray

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