TWI Scanner Example problem

[simon1516]

Hi,

I´m trying to work with the "TWI Scanner" example, provided by SDK 16. I Use nRF52833 DK (PCA10010), unfortunaly there is no solution for PCA 10010 in the SDK. This is why I flashed PCA10040 to my nRF52833 DK.

And I got the message "TWI scanner started." from UART terminal, so I think the example also works on nRF52833 DK.

So, I´ve done just one modification to the example: I change SCL and SDA Pin to 33 and 34 (P1.02 and P1.03 of nRF52833 DK) as shown in screenshot attached (here I´m not sure with!).

Unfortunaly, I can´t find my I2C device. With another I2C scanner I can found the I2C device. I connect it to the nRF52833 DK with two pullups, 3k3 Ohm and another try without pullups - both isn´t working.Do I also have to connect AREF_PI ?What else can be the reason?

For information: As I2C device I just use a small Sensor developer board with I2C interface.

Thanks in advance

Simon

[Kenneth]

I made some screenshots on how to turn an nRF52840 (PCA10056) project into an nRF52833 (PCA10100) project. Hope it helps.

If you still have issues I suggest to get an logic analyzer (e.g. https://www.saleae.com/) to check out data on the SCL and SDA pins.

[simon1516]

Hi,

after doing this, I got an error when trying to compile.

I also looked at this thread

But the steps are the same like you described. When I successful build and run the example without modification I have tried to set an digital output to high - it doesn´t work. So it seems that the Pin´s are not mapped correctly. Can you help me with this error and have a look to my configuration? I just show you the modified rows attached.

thanks in advance

Simon

[simon1516]

Update: After a few tries, it works now. Please don´t ask me, what I´ve done wrong before. I got the message "TWI scanner started." by UART.

Unfortunaly, I don´t get a message "TWI device detected at address 0x%x.", allthough "detected_device"=true

Do you have an idea for that?

In addition to that, I buy a logic analyzer for future, but shipping is about 1 week :-/

[simon1516]

I think I have an issue because of

simon1516 said:

I change SCL and SDA Pin to 33 and 34 (P1.02 and P1.03 of nRF52833 DK) as shown in screenshot attached (here I´m not sure with!).

Could you please confirm that this is okay for I2C Pin´s?

[Kenneth]

Any pins should in theory be possible to use for SCL/SDA, however you may need to flip the DK and check if any of the pins have specific usage by default (since they are DK).

I notice on your first picture you wrote PCA10010, while it should be PCA10100.

Kenneth

[simon1516]

Kenneth said:

you may need to flip the DK and check if any of the pins have specific usage by default (since they are DK).

Thats it! I used other pin´s, I thought it would working with every pin. But on nRF52833 DK  just p0.26 and p0.27 are used for SDA and SCL.

Thanks for help.