Best place to get started

[sd]

Hello everyone.

I've got the nRF51822 Evaluation Kit and Dongle. The heartbeat demo is working, so I got the toolchain -- Nordic, Keil, Segger under Win7 -- set up correctly, as far as I can tell.

I need to interface with an I2C/TWI device as one of my peripherals, and was wondering what is the best way to start a new project, and if there's a template that I could use that will do much of the required setup (SoftDevice, initialisation, etc.) for me. Or do most people simply start off with the example code and build on top of that?

Finally, is there a "getting started" guide anywhere? I couldn't find one on the Nordic website.

Thanks!

[Håkon Alseth]

Hi,

If you want to start with a new project and setup all your characteristics and services, there is a blank project called "ble_app_template".

The TWI uses some PPI channels, which is restricted when the SoftDevice S110 is active. Please use the attached .c file for TWI communication when using it with S110 BLE stack.

The getting started is a small part of the user guide for the EV/DEV kit. Here's a quick link to the EV kit user guide: www.nordicsemi.com/.../21312489

BR Håkon

sd_twi_hw_master (2).c

[sd]

Thanks! The "ble_app_template" is under a different board; does that matter? Also, the TWI example is the API -- is there an example of how to set the pins and other registers?

[Håkon Alseth]

You can see the "twi_sw_master_example" in the SDK to see how to init the library (it uses bit banged TWI, but library calls are equal). The "ble_app_template" has one button set up, which is "WAKEUP_BUTTON_PIN". This must match the button on your board (GPIO 16 or 17, if my memory serves me right). Other than that there should be no other issues using this example on the ev board.

[Ole Morten]

To clean things up, I'd be happy if you could evaluate the answer you have received and accept it if you feel it's sufficient. If not, it might be useful to expand your question a little and provide further information.

[Wobs]

Hi,

I'm using the attached, modified, SoftDevice compatible TWI code with the BLE heart rate example for the pca10001. I initialize the TWI master like in this order:

int main(void)
{
    uint32_t err_code;

    timers_init();
    gpiote_init();
    buttons_init();
	
    // Initialize TWI
    twi_master_init();

and the code fails at the asserts and forces a system reset...

    /*
    NRF_PPI->CH[0].EEP = (uint32_t)&NRF_TWI1->EVENTS_BB;
    NRF_PPI->CH[0].TEP = (uint32_t)&NRF_TWI1->TASKS_SUSPEND;
    NRF_PPI->CHENCLR = PPI_CHENCLR_CH0_Msk;*/
    err_code = sd_ppi_channel_assign(0,
                                     &(NRF_TWI1->EVENTS_BB),
                                     &(NRF_TWI1->TASKS_SUSPEND));
    ASSERT(err_code == NRF_SUCCESS);

What is the problem here, shall I initialize the TWI in a different order?