app twi with ads1015 init transfer error

[chenyang08s]

I tried to modify the twi_master_using_app_twi to work with adafruit ADS1015 as a slave. I ran into this problem. It seems that the init_transfer doesn't finish so the app_twi_perform command just keeps it hanging. Can someone tell me how to fix this? Thanks.

[Anders Strand]

Hi.

I would check a couple of things:

• Is the pins assigned to TWI correct? Are they used by something else like UART or RTC?
• Does the app_twi_perform return with an error code? If so, which error code? See this post for more detail.
• The next step is to use a logic analyzer on the pins and see if there is any TWI traffic at all.

-Anders

[chenyang08s]

Thanks for helping! I think the pins are correct, I checked the error code and it appears to be 0x00000003. Any idea what this means?

[Anders Strand]

Is it NRF_ERROR_INTERNAL.

This means that the TWI transfer was unsuccessful due to the slave sending a NACK on either the address byte or the following bytes. You need to double check that you are sending the correct address and data according to the slave device data sheet. You should also get a logic analyzer and see what is actually happening on the bus

[Rocky Liang]

@chenyang08s, have you solve your TWI problem? If you have, could you please tell me what the problem was? I am experiencing the same program as you did in my project.