S140 + TWI working together - problems

[tozitom]

hi Forum.
I'm working on a project with nrf52840 + S140 + TWI (SDK v16). Got all working separatly on my custom board, i.e. softdevice alone works fine and TWI also works with different SDK examples (also I can adapt them to my needs...). The problem is when I join them together...TWI doesn't work properly any more.

Example: I can get Scanner example working before starting softdevice, but if I insert any "nrf_drv_twi_tx" or "nrf_drv_twi_rx" I get stuked  on "while (m_xfer_done == false)"; it never jumps to twi_handler, even after confirming (with I2C signal analyser) that the command is sent to my I2C device . I already loose several days trying to fix this, but can't get it work.

Also, can you advice correct way to get TWI work with S140? from what I've been here in forum it's the TWI HW way, correct? but I got somehow confused with the SDK v16 examples.

Thanks to all for reading.

[tovine]

Hi,

My initial thought when you say it's all working separately but not when combined with the softdevice, is that there might be some issue with interrupt priorities?

See this page for more details: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsds_s140%2FSDS%2Fs1xx%2Fprocessor_avail_interrupt_latency%2Fexception_mgmt_sd.html&cp=4_7_4_0_15_1

Best regards,
Torbjørn

[tozitom]

thanks Torbjørn.
I've been reading the page you sent me, and related links but still haven't figure out this iussue yet.
my sdk_config.h has all TWI...IRW_PRIORITY set to 6

in this case, which priority level should be TWI on? 2/3 or 5/6/7

also I'm still confused on different TWI examples (SDK v16) - which one is the example for HW TWI? twi_sensor/twi_scanner/twi_master_using_nrf_twi_mngr/twi_master_with_twis_slave?

best regards.

[Jared]

Hi,

What Softdevice operations are you doing? Are you in a connection when you try to the TWi transfer? Could post your main.c and SDK config file? 

regards

Jared 

[tozitom]

Hi Jared.
I managed to get it work: had to start all over with a "clean" code working on BLE, and add TWI code to it.
Also I do not know exactly where the problem was, as I'm stil confused with the sdk_config.h definitions on TWI...
In case it's any help for someone with same issues, I'm using the "twi_sensor" example from SDK160098 and active following defines:

TWI_ENABLED                   1
TWI0_ENABLED                 1
TWI0_USE_EASY_DMA     1

Where can I find more detail info on TWI definitions/configurations? As I said, I'm still a little confused with the different ways to configure TWI.

Best Regards.

[tovine]

Hi, glad to hear you managed to get it working!

Sorry about not responding sooner, I was about to write a reply but then I got lost in work and forgot about it...

I don't have that much experience with the SDK and how it works, but if you're wondering about the TWI itself I can recommend reading the peripheral chapters on the infocenter:

• https://infocenter.nordicsemi.com/topic/ps_nrf52840/twi.html?cp=4_0_0_5_28 - the main TWI chapter
• https://infocenter.nordicsemi.com/topic/ps_nrf52840/twim.html?cp=4_0_0_5_30 - the TWI module configured as a master, with EasyDMA enabled (this is probably what you get when defining TWI0_USE_EASY_DMA)
• (maybe not as relevant, but https://infocenter.nordicsemi.com/topic/ps_nrf52840/twis.html?cp=4_0_0_5_31 - the TWI module configured as a slave, with EasyDMA enabled)

For more SDK/driver-specific information, you can take a look here: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.0.0/hardware_driver_twi.html?cp=7_1_2_0_17 - the documentation for the TWI driver in the nRF5 SDK