when trying to initialize the nrf52...little bit confused how to specifically address a pin for i2c....can anyone help me with a piece of code. Thank you in advance.
when trying to initialize the nrf52...little bit confused how to specifically address a pin for i2c....can anyone help me with a piece of code. Thank you in advance.
yes..m just trying to read revision id register (0x81)...it is supposed to return 21..i am new to twi
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/** @file
* @defgroup tw_sensor_example main.c
* @{
* @ingroup nrf_twi_example
* @brief TWI Sensor Example main file.
*
* This file contains the source code for a sample application using TWI.
*
*/
#include <stdio.h>
#include "boards.h"
#include "app_util_platform.h"
#include "app_error.h"
#include "nrf_drv_twi.h"
#include "nrf_delay.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
/* TWI instance ID. */
#define TWI_INSTANCE_ID 0
/* Common addresses definition for temperature sensor. */
#define vcnl4020_ADDR (0x13U>>1)
#define vcnl4020_REG_command 0x80U
#define vcnl4020_REG_PRODUCT_ID_REVISION_REGISTER 0x81U
#define LM75B_REG_THYST 0x02U
#define LM75B_REG_TOS 0x03U
/* Mode for LM75B. */
#define NORMAL_MODE 0U
/* Indicates if operation on TWI has ended. */
static volatile bool m_xfer_done = false;
/* TWI instance. */
static const nrf_drv_twi_t m_twi = NRF_DRV_TWI_INSTANCE(TWI_INSTANCE_ID);
/* Buffer for samples read from temperature sensor. */
static uint8_t m_sample;
/**
* @brief Function for setting active mode on MMA7660 accelerometer.
*/
ret_code_t vcnl4020_set_mode()
{
ret_code_t err_code;
/* Writing to LM75B_REG_CONF "0" set temperature sensor in NORMAL mode. */
uint8_t reg[1] = {0x80};
err_code = nrf_drv_twi_tx(&m_twi, vcnl4020_ADDR, reg, sizeof(reg), false);
APP_ERROR_CHECK(err_code);
while (NRF_DRV_TWI_EVT_DONE == false);
return (err_code);
/* Writing to pointer byte. */
reg[0] = vcnl4020_REG_PRODUCT_ID_REVISION_REGISTER;
m_xfer_done = false;
err_code = nrf_drv_twi_tx(&m_twi, vcnl4020_ADDR, reg, 1, false);
APP_ERROR_CHECK(err_code);
while (m_xfer_done == false);
}
/**
* @brief Function for handling data from temperature sensor.
*
* @param[in] temp Temperature in Celsius degrees read from sensor.
*/
__STATIC_INLINE void data_handler(uint8_t temp)
{
NRF_LOG_INFO("Temperature: %d Celsius degrees.", temp);
}
/**
* @brief TWI events handler.
*/
void twi_handler(nrf_drv_twi_evt_t const * p_event, void * p_context)
{
switch (p_event->type)
{
case NRF_DRV_TWI_EVT_DONE:
if (p_event->xfer_desc.type == NRF_DRV_TWI_XFER_RX)
{
data_handler(m_sample);
}
m_xfer_done = true;
break;
default:
break;
}
}
/**
* @brief UART initialization.
*/
void twi_init (void)
{
ret_code_t err_code;
const nrf_drv_twi_config_t twi_lm75b_config = {
.scl = ARDUINO_SCL_PIN,
.sda = ARDUINO_SDA_PIN,
.frequency = NRF_DRV_TWI_FREQ_100K,
.interrupt_priority = APP_IRQ_PRIORITY_HIGH,
.clear_bus_init = false
};
err_code = nrf_drv_twi_init(&m_twi, &twi_lm75b_config, twi_handler, NULL); //non-blocking mode...in blocking mode no twi_handler in provided and doen not uses interrupt
APP_ERROR_CHECK(err_code);
nrf_drv_twi_enable(&m_twi);
}
/**
* @brief Function for reading data from temperature sensor.
*/
static int read_sensor_data()
{
m_xfer_done = false;
bool t;
uint32_t event;
ret_code_t err_code,err;
uint8_t reg[1] = {0x81U};
err_code = nrf_drv_twi_tx(&m_twi, vcnl4020_ADDR, ®[0], 1, false);
APP_ERROR_CHECK(err_code);
// if(err_code != NRF_SUCCESS) {
// return err_code;
// }
/* Read 1 byte from the specified address - skip 3 bits dedicated for fractional part of temperature. */
// err_code=(0x13U>>1);
err = nrf_drv_twi_rx(&m_twi, vcnl4020_ADDR, &m_sample, sizeof(m_sample));
event = nrf_drv_twi_stopped_event_get(&m_twi);
t = nrf_drv_twi_is_busy(&m_twi); // true If the TWI driver is currently busy performing a transfer
while(m_xfer_done==false);
APP_ERROR_CHECK(err);
return (err_code);
return (m_sample);
}
/**
* @brief Function for main application entry.
*/
int main(void)
{
ret_code_t rslt;
uint8_t out_t;
APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
NRF_LOG_DEFAULT_BACKENDS_INIT();
NRF_LOG_INFO("\r\nTWI sensor example started.");
NRF_LOG_FLUSH();
twi_init();
// vcnl4020_set_mode();
while (true)
{
// nrf_delay_ms(500);
//
// do
// {
// __WFE();
// }while (m_xfer_done == false);
//
rslt = read_sensor_data();
NRF_LOG_FLUSH();
}
}
/** @} */
this is what i am doing...the code is getting stuch at " while(m_xfer_done==false);"
t = nrf_drv_twi_is_busy(&m_twi); function returns true indicating that it is busy..why is nrf52832 is busy reading register... i am not understanding...will you help..
thank you for your reply