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Date:      Thu, 21 Sep 2023 14:10:57 +0200
From:      "Patrick M. Hausen" <pmh@hausen.com>
To:        freebsd-arm <freebsd-arm@freebsd.org>
Subject:   FreeBSD 14, RPI CM3+ - how to use I2C?
Message-ID:  <8B10870E-C485-4626-BBCF-BEE0771D8B5A@hausen.com>

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Next topic with my TuringPi ...

The CM placed in slot 1 has got access to the management bus
of the TuringPi mainboard.

The documentation states that one should add these to config.txt:

dtoverlay=3Di2c1,pins_44_45
dtoverlay=3Di2c-rtc,mcp7940x

Source: =
https://docs.turingpi.com/docs/turing-pi1-cluster-management-bus-i2c

Did that, but

i2c -s

shows now output and

root@pi1:~ # i2c -a 0x57 -o 0xf2 -d r -c 1
i2c: ioctl(I2CRDWR) failed: Input/output error

root@pi1:~ # grep iic /var/run/dmesg.boot=20
iichb0: <BCM2708/2835 BSC controller> mem 0x7e804000-0x7e804fff irq 20 =
on simplebus0
iicbus0: <OFW I2C bus> on iichb0
iic0: <I2C generic I/O> on iicbus0

Any hints on how to get this working?

Kind regards,
Patrick=



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