Nrf52832 + SDK 12.3 + SD 132 : TWI Not Working. No Output

[Ankit Bhatnagar]

Hi All,

I am trying to use TWI on NRF52832 using SDK 12.3 + SD132 but without any success.

For some reason, there is no signal coming out on the configured SDA + SCL pins. I checked using a logic analyzer. I tried using both the blocking and non blocking mode without any success. The pins that I am using are

SDA : 13

SCL : 12

My sdk_config.h section is

// <e> TWI_ENABLED - nrf_drv_twi - TWI/TWIM peripheral driver
//==========================================================
#ifndef TWI_ENABLED
#define TWI_ENABLED 1
#endif
#if  TWI_ENABLED
// <o> TWI_DEFAULT_CONFIG_FREQUENCY  - Frequency
 
// <26738688=> 100k 
// <67108864=> 250k 
// <104857600=> 400k 

#ifndef TWI_DEFAULT_CONFIG_FREQUENCY
#define TWI_DEFAULT_CONFIG_FREQUENCY 26738688
#endif

// <q> TWI_DEFAULT_CONFIG_CLR_BUS_INIT  - Enables bus clearing procedure during init
 

#ifndef TWI_DEFAULT_CONFIG_CLR_BUS_INIT
#define TWI_DEFAULT_CONFIG_CLR_BUS_INIT 0
#endif

// <q> TWI_DEFAULT_CONFIG_HOLD_BUS_UNINIT  - Enables bus holding after uninit
 

#ifndef TWI_DEFAULT_CONFIG_HOLD_BUS_UNINIT
#define TWI_DEFAULT_CONFIG_HOLD_BUS_UNINIT 0
#endif

// <o> TWI_DEFAULT_CONFIG_IRQ_PRIORITY  - Interrupt priority
 

// <i> Priorities 0,2 (nRF51) and 0,1,4,5 (nRF52) are reserved for SoftDevice
// <0=> 0 (highest) 
// <1=> 1 
// <2=> 2 
// <3=> 3 
// <4=> 4 
// <5=> 5 
// <6=> 6 
// <7=> 7 

#ifndef TWI_DEFAULT_CONFIG_IRQ_PRIORITY
#define TWI_DEFAULT_CONFIG_IRQ_PRIORITY 7
#endif

// <e> TWI0_ENABLED - Enable TWI0 instance
//==========================================================
#ifndef TWI0_ENABLED
#define TWI0_ENABLED 1
#endif
#if  TWI0_ENABLED
// <q> TWI0_USE_EASY_DMA  - Use EasyDMA (if present)
 

#ifndef TWI0_USE_EASY_DMA
#define TWI0_USE_EASY_DMA 1
#endif

#endif //TWI0_ENABLED
// </e>

// <e> TWI1_ENABLED - Enable TWI1 instance
//==========================================================
#ifndef TWI1_ENABLED
#define TWI1_ENABLED 0
#endif
#if  TWI1_ENABLED
// <q> TWI1_USE_EASY_DMA  - Use EasyDMA (if present)
 

#ifndef TWI1_USE_EASY_DMA
#define TWI1_USE_EASY_DMA 0
#endif

#endif //TWI1_ENABLED
// </e>

// <e> TWI_CONFIG_LOG_ENABLED - Enables logging in the module.
//==========================================================
#ifndef TWI_CONFIG_LOG_ENABLED
#define TWI_CONFIG_LOG_ENABLED 0
#endif
#if  TWI_CONFIG_LOG_ENABLED
// <o> TWI_CONFIG_LOG_LEVEL  - Default Severity level
 
// <0=> Off 
// <1=> Error 
// <2=> Warning 
// <3=> Info 
// <4=> Debug 

#ifndef TWI_CONFIG_LOG_LEVEL
#define TWI_CONFIG_LOG_LEVEL 3
#endif

// <o> TWI_CONFIG_INFO_COLOR  - ANSI escape code prefix.
 
// <0=> Default 
// <1=> Black 
// <2=> Red 
// <3=> Green 
// <4=> Yellow 
// <5=> Blue 
// <6=> Magenta 
// <7=> Cyan 
// <8=> White 

#ifndef TWI_CONFIG_INFO_COLOR
#define TWI_CONFIG_INFO_COLOR 0
#endif

// <o> TWI_CONFIG_DEBUG_COLOR  - ANSI escape code prefix.
 
// <0=> Default 
// <1=> Black 
// <2=> Red 
// <3=> Green 
// <4=> Yellow 
// <5=> Blue 
// <6=> Magenta 
// <7=> Cyan 
// <8=> White 

#ifndef TWI_CONFIG_DEBUG_COLOR
#define TWI_CONFIG_DEBUG_COLOR 0
#endif

#endif //TWI_CONFIG_LOG_ENABLED
// </e>

#endif //TWI_ENABLED
// </e>

My TWI initialization code is 

bool INTERNAL_I2C_Init(void)
{
    //INITIALZE INTERNAL_I2CTWIMASTER_TWI_INST_USE_EASY_DMA

    //ONLY INITIALIZE IF NOT ALREADY DONE
    if(s_initialized)
    {
        return true;
    }

    //INITIALIZE DRIVER
    ret_code_t ret;
    const nrf_drv_twi_config_t config = {
                                            .scl = BSP_EXTERNAL_DS3231_SCL,
                                            .sda = BSP_EXTERNAL_DS3231_SDA,
                                            .frequency = NRF_TWI_FREQ_100K,
                                            .interrupt_priority = APP_IRQ_PRIORITY_LOW,
                                            .clear_bus_init = false
                                        };
    
    do
    {
        ret = nrf_drv_twi_init(&s_internal_twi_handle, 
                                &config, 
                                s_internal_i2c_event_handler, 
                                NULL);
        if(ret != NRF_SUCCESS)
        {
            break;
        }
        nrf_delay_ms(2000);
        nrf_drv_twi_enable(&s_internal_twi_handle);
        nrf_delay_ms(2000);
        UTIL_DebugPrint(MODULE_NAME_I2C"%s OK\n", __FUNCTION__);
        s_initialized = true;
        return true;
    }while(0);

    UTIL_DebugPrint(MODULE_NAME_I2C"%s FAIL\n", __FUNCTION__);
    return false;
}

and the write function is 

bool INTERNAL_I2C_WriteData(uint8_t i2c_add, uint8_t reg_add, uint8_t* buff, uint8_t len)
{
    //SEND THE SPECIFIED DATA OF SPECIFIED LENGTH TO THE SPECIFIED REGISTER ADDRESS
    //THROUGH I2C INTERFACE

    //WAIT FOR ONGOING OPERATOIN TO FINISH
    while(s_operation_ongoing)
    {

    }
    
    ret_code_t ret;
    uint8_t final_data[len + 1];

    //CREATE DATA BUFFER
    final_data[0] = reg_add;
    memcpy(&final_data[1], (const void * restrict)buff, len);

    UTIL_DebugPrint(MODULE_NAME_I2C"A\n");

    //SLA+W + REGISTER_ADDRESS + WRITE_DATA + STOP
    s_operation_ongoing = true;
    ret = nrf_drv_twi_tx(&s_internal_twi_handle,
                            i2c_add,
                            final_data,
                            (len + 1),
                            false);
    UTIL_DebugPrint(MODULE_NAME_I2C"tx ret code %u\n", ret);
    if(ret != NRF_SUCCESS)
    {
        return false;
    }
    UTIL_DebugPrint(MODULE_NAME_I2C"B\n");
    return true;
}

When I write some data to the twi device (DS3231), the i2c write function returns with the data is never actually sent out. I checked the i2c device and it is working fine. I am able to communicate to it using bus pirate.

Not sure what I could be doing wrong here. Any help is appreciated.

[MartinBL]

Is the function INTERNAL_I2C_WriteData() returning true or false? In other words, is nrf_drv_twi_tx() returning something else than NRF_SUCCESS?

What pin numbers have you used for BSP_EXTERNAL_DS3231_SCL and BSP_EXTERNAL_DS3231_SDA?

Are you using a customer board or a development kit?

[Ankit Bhatnagar]

nrf_drv_twi_tx() always returns NRF_SUCCESS.

The pins that I'm using are

SDA 13

SCL 12

This is a custom board with external I2C pull ups

[Ankit Bhatnagar]

I tried with SDK15, SD 132 v 6.0 with exactly the same behaviour. No data sent out on the pins ane hence the twi event handler is never called. Also tried using other pins (20 and 24) with same result

[MartinBL]

Are you using a development kit or a custom board? If you are using a customer board, do you also have a kit you can try?

Can you upload your project? We can make the case private if you prefer confidentiality. 

 

[Ankit Bhatnagar]

Sorry to have wasted your time but it turned out to be a hardware issue. There was another I2C device connected on the bus whose pins were incorrectly mapped. Removing it fixed the issue.