Pi PICO No Hardware I2C on Channel 1 or Channel 2

[jay_dee]

Hi FC Team,
Working through PICO functions and cant raise any responce from the hardware IC2 channels.
Very simple test routine attached.
On a bare and new PICO. Only has LED on GP4 and Pull up resistors on SDA & SCK.

using I2C master component (sims OK)
Software - Get a I2C signal as expected.
Channel 1 - Tried pins A0/A1 and A12/A13 - No responce.
Channel 2 - Tried pins A10/A11 - no responce.

I dont think I'm doing anything silly.
Has anyone else has I2C harware channels working on Pi PICO?
Thanks, J.

[LeighM]

I sure have
I might get chance to dig one out over the weekend.

[jay_dee]

Thanks Leigh...not sure what i have stuffed up then. an known working example would be great.

[chipfryer27]

Hi

Pretty sure I had a display running a few months back. I'll check.

I too really like the Pico.

Regards

Edit.....

I did use an I2C display with no issues in this post viewtopic.php?f=3&t=2041&hilit=pico&start=10

I used Ch1 with SDA on A.16 and SCL on A.17

[chipfryer27]

Hi

I did have an issue when using an I2C sensor, which transpired to be the connector, and in testing I used Martin's I2C sniffer as per this post

viewtopic.php?f=5&t=2099

It might be helpful to try that? It's a great little tester.

If you have a logic analyser or a scope that would help confirm activity.

Regards

[jay_dee]

Thanks Chipfryer,
Luckily I have a Agilent scope on the job and I get a lovely trace if I set the output to software.
Just change the single setting to one of the hardware I2C channels and I get nothing....that is just a bit odd for me.

I have this setup on a stand alone PICO with only a status LED to confirm the Main loop is running and two pull up resistors as the abolsolute minimum to prove an I2C and remove any other odd hardware issues.
There is no slave device in this test setup but I'm pretty sure from previous tests you can send out a write request and the micro will at least toggle the lines.
Have latest FC updates etc and swept all ofthe other pins with the scope to ensure it not just an output pin confusion.

[chipfryer27]

Hi

I can probably try that later today with an analyser on the pins.

Regards

[chipfryer27]

Hi

Seems an issue with the component (I2C Master).

Created a very simple chart using I2C Master with SDA on A.16 and SCL on A.17 with 4.7K resistors to 3.3v on the hardware.

I also made pin A.18 go high immediately before any I2C transmission, going low at the end of test.

Using Software chanel I got as expected.

PICO_I2C_Software.jpg (54.12 KiB) Viewed 261 times

When changing to Ch1 or Ch2 nothing.

PICO_I2C_Ch1.jpg (41.92 KiB) Viewed 261 times

Regards

[jay_dee]

Chipfryer. Many thanks for confirming what I get on my scope too. J. I'm always cautious it is something dumb on my end!

[chipfryer27]

Chipfryer. Many thanks for confirming what I get on my scope too. J. I'm always cautious it is something dumb on my end!

Join the club......

Won't say how long it took me to remember to push the Pico button before inserting lead into PC....