TWI Does not work

[Nasib]

Hello, i am trying to develope a I2C  application. 

I am using the twi_sensor example of the SDK 12.3.0

I have configured my pins to SDA 14 and SCL 30 and i just want to send some data with the  nrf_drv_twi_tx funtion... but nothing happens. I am monitoring the gpio 14 and the gpio 30 with my osciloscope and i just see the 3.3v provided by the pull up resistor... nothing else... 

What i am doing wrong ?

Thank you so much in advance 

Best regards 

[Håkon Alseth]

Hi,

 

If nothing is connected, then it only sends one command and waits for an ACK in the twi_handler.

Try power cycling your nrf and see if it initially sends one transaction.

 

Kind regards,

Håkon

[Nasib]

Yes there is a sensor connected. But even with the sensor or with out i dont see any comand sent with my oscilloscope 

[Håkon Alseth]

But, does it ACK the command you send? If you scope the initial communication, you should be able to see if the ACK bit is set or not.

Kind regards,

Håkon

[Nasib]

Thanks for your answer. What happens here is that even if I send the command in the main endless loop I am not able to see anything in the scope. Anything, no a single bit. And of course not a single ack. 

Is there any pre configuration that I should do to use this example ? 

[Håkon Alseth]

The program will send one transfer, wait for a successful event, then do another.

If the transfer is not successful, it will send one transaction and then hang forever. This is the reason why I asked if you could reset the device and capture the trace and see if you get any output on SCL/SDA pins. Regardless, this points towards a issue with addressing the i2c sensor. Please doublecheck that the i2c address is correct, and please verify that the i2c master sends anything on boot-up.

 

Kind regards,

Håkon