nrf52832 IIC easyDma not work

[yanli_1226]

hello,

I have a problem when using the example  twi_sensor with nrf52832( nRF5_SDK_15.3.0_59ac345\examples\peripheral\twi_sensor\pca10040\blank\arm5_no_packs)

This example use LM75B, as I don't have this sensor, I changed the IIC address with an existing sensor,so the IIC can be replyed correctly.

then I change the length in read_sensor_data(), because I want more IIC CLK(it's just for test, I don't change other config code)

when len in this function( nrf_drv_twi_rx(&m_twi, LM75B_ADDR, &m_sample, len); ) is configed larger than three, such as four, the function will not work, what's the matter please?

static void read_sensor_data()
{
    m_xfer_done = false;

    /* Read 1 byte from the specified address - skip 3 bits dedicated for fractional part of temperature. */
    ret_code_t err_code = nrf_drv_twi_rx(&m_twi, LM75B_ADDR, &m_sample, 3);
    APP_ERROR_CHECK(err_code);
}

[yanli_1226]

ret_code_t err_code = nrf_drv_twi_rx(&m_twi, LM75B_ADDR, &m_sample, len);

when config len = 4，the info is as bellow：

<info> app: 

TWI sensor example started.

when config len = 3，the info is as bellow：

<info> app: 

TWI sensor example started.

<info> app: Temperature: 0 Celsius degrees.

<info> app: Temperature: 0 Celsius degrees.

<info> app: Temperature: 0 Celsius degrees.

....

as I am not using lm75b, so the Temperature out is 0

[Sigurd]

Try to configure the m_sample to be an array instead,

/* Buffer for samples read from temperature sensor. */

static uint8_t m_sample[4];

then do

nrf_drv_twi_rx(&m_twi, LM75B_ADDR, m_sample, sizeof(m_sample));

[yanli_1226]

thank you , it  need a  m_xfer_done = false; and wait for  m_xfer_done flag;