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Mettauk
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Damaged GPIO 2 SDA

Thu Feb 08, 2018 4:48 pm

Think I may have fried a Pi3b as on testing GPIO 2 (Pin 3) SDA1 I2C as on test I get 0.60v which should be 3.3 ish. I need to use I2c and am wondering is there an alternative pin?

Wishful thinking or another £33?
As humans we have been the same for a very very long time, technology changes how we do... not who we are as people.

fivdi
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Re: Damaged GPIO 2 SDA

Fri Feb 09, 2018 8:33 pm

The Pi 3 has a second I2C bus on pins 27 and 28.
Perhaps that works.
See https://pinout.xyz/pinout/i2c#
See also viewtopic.php?f=44&t=137848

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Mettauk
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Re: Damaged GPIO 2 SDA

Fri Feb 09, 2018 10:17 pm

Thank you, very useful for other projects but as I need the camera to, this is not an option on this occasion.
As humans we have been the same for a very very long time, technology changes how we do... not who we are as people.

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FTrevorGowen
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Re: Damaged GPIO 2 SDA

Fri Feb 09, 2018 10:47 pm

There is a device tree overlay that can provide ("bitbanged") I2C support on other (spare) GPIO's:
viewtopic.php?t=40743#p1262373
Trev.
Still running Raspbian Jessie on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W) but Stretch on my 2xP3A+, P3B+, P3B, B+, A+ and a B2. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

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joan
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Re: Damaged GPIO 2 SDA

Sat Feb 10, 2018 9:08 am

I think the linked bit bang solution predates the Pi Linux kernel software I2C.

At the moment it's probably best to use the Linux kernel version as enabled by device tree. Details in /boot/overlays/README.

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FTrevorGowen
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Re: Damaged GPIO 2 SDA

Sat Feb 10, 2018 10:58 am

joan wrote:
Sat Feb 10, 2018 9:08 am
I think the linked bit bang solution predates the Pi Linux kernel software I2C.
At the moment it's probably best to use the Linux kernel version as enabled by device tree. Details in /boot/overlays/README.
You may well be correct, but, AFAICT (haven't tested) from the dtoverlay README file, it (possibly a newer replacement for that in the thread) is enabled via the same/similar mechanism. Whether the actual overlay activated has some, all or more "features" than the "original" from the early part of the thread IJDK - I guess it depends on exactly what (features) the O.P. needs.
Trev.
Still running Raspbian Jessie on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W) but Stretch on my 2xP3A+, P3B+, P3B, B+, A+ and a B2. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

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