yefj
Advanced Member level 5
Hello,I have tried to follow the I2C diagram of Si7021 bellow step by step .
first from the starter kit manuak my SDA and SCL is P13 and P12 on my board respectivly which is location 15 in the datasheet page 150 table shown bellow.
I have been writing and reading exactly by the registers in the reference manual shown bellow.
i have test if one step accomplished before going to the next step as shown in the code bellow every line has a comment regarding which step its in the I2C diagram.
the real connection is shown bellow.I am sending this whole procedure over and over in while(1) loop.
And i get only Noise no digital behavior at all on my scope.
Where did i go wrong?
Thanks.
EFR32FG14 starter kit manual
Si7021 sensor page 20
Efr32fg14 reference manual
Efr32fg14 data sheet page 150
first from the starter kit manuak my SDA and SCL is P13 and P12 on my board respectivly which is location 15 in the datasheet page 150 table shown bellow.
I have been writing and reading exactly by the registers in the reference manual shown bellow.
i have test if one step accomplished before going to the next step as shown in the code bellow every line has a comment regarding which step its in the I2C diagram.
the real connection is shown bellow.I am sending this whole procedure over and over in while(1) loop.
And i get only Noise no digital behavior at all on my scope.
Where did i go wrong?
Thanks.
EFR32FG14 starter kit manual
Si7021 sensor page 20
Efr32fg14 reference manual
Efr32fg14 data sheet page 150
Code:
#include <stdio.h>
#include "em_device.h"
#include "em_chip.h"
#include "em_i2c.h"
#include "em_cmu.h"
#include "em_emu.h"
#include "em_gpio.h"
#include "bsp.h"
// Buffers
uint8_t i2c_txBuffer[] = "Gecko";
uint8_t i2c_txBufferSize = sizeof(i2c_txBuffer);
uint8_t MS_Byte;
uint8_t LS_Byte;
uint8_t checksum;
int flag_2nd_step=0;
int flag_3rd_step=0;
/**************************************************************************//**
* @brief Starting oscillators and enabling clocks
*****************************************************************************/
void initCMU(void)
{
// Enabling clock to the I2C, GPIO, LE
CMU_ClockEnable(cmuClock_I2C0, true);
CMU_ClockEnable(cmuClock_GPIO, true);
CMU_ClockEnable(cmuClock_HFLE, true);
// Starting LFXO and waiting until it is stable
CMU_OscillatorEnable(cmuOsc_LFXO, true, true);
}
/**************************************************************************//**
* @brief Setup I2C
*****************************************************************************/
void initI2C(void)
{
// Using default settings
I2C_Init_TypeDef i2cInit = I2C_INIT_DEFAULT;
// Use ~400khz SCK
i2cInit.freq = I2C_FREQ_FAST_MAX;
// Using PC10 (SDA) and PC11 (SCL)
GPIO_PinModeSet(gpioPortC, 10, gpioModeWiredAndPullUp, 1);
GPIO_PinModeSet(gpioPortC, 11, gpioModeWiredAndPullUp, 1);
//Si7021 switch on
GPIO_PinModeSet(gpioPortD, 15, gpioModePushPull, 1);
// Enable pins at location 15 as specified in datasheet
I2C0->ROUTEPEN = I2C_ROUTEPEN_SDAPEN | I2C_ROUTEPEN_SCLPEN;
I2C0->ROUTELOC0 = (I2C0->ROUTELOC0 & (~_I2C_ROUTELOC0_SDALOC_MASK)) | I2C_ROUTELOC0_SDALOC_LOC15;
I2C0->ROUTELOC0 = (I2C0->ROUTELOC0 & (~_I2C_ROUTELOC0_SCLLOC_MASK)) | I2C_ROUTELOC0_SCLLOC_LOC15;
// Initializing the I2C
I2C_Init(I2C0, &i2cInit);
}
int main(void)
{
// Chip errata
CHIP_Init();
// Configuring clocks in the Clock Management Unit (CMU)
initCMU();
// Setting up i2c
initI2C();
while(1)
{
I2C0->CMD=I2C0->CMD|(1<<0); //step 1 start CMD
I2C0->TXDATA=((I2C0->TXDATA)&(0xFF00))|(0x80); //step 2 sending sensor address with 0 write bit
while(((I2C0->IF)&(1<<4))!=1){}//wait till command transfer ends TXBL flag
if (((I2C0->IF)&(1<<6))==1)//if we recieve ACK send measure and read command //3rd step
{
I2C0->TXDATA=((I2C0->TXDATA)&(0xFF00))|(0xE3); //step 4 in diagram
while(((I2C0->IF)&(1<<4))!=1){}//wait till command transfer ends TXBL flag
if (((I2C0->IF)&(1<<6))==1)//if we recieve ACK after Measure CMD
{
flag_2nd_step=1;
}
}
else //if we recieve NACK we send the previos command again
{
I2C0->TXDATA=((I2C0->TXDATA)&(0xFF00))|(0x80); //step 2 sending sensor adress with 0 write bit
while(((I2C0->IF)&(1<<4))!=1){}//wait till command transfer ends TXBL flag
flag_2nd_step=0;
}
if (flag_2nd_step==1) //step 3 second slave adress sending
{
I2C0->CMD=I2C0->CMD|(1<<0); //step 5 start CMD
I2C0->TXDATA=((I2C0->TXDATA)&(0xFF00))|(0x81); //step 6 sending sensor adress with 1 read bit
while(((I2C0->IF)&(1<<4))!=1){}//wait till command transfer ends TXBL flag
flag_3rd_step=1;
}
if (flag_3rd_step==1)
{
while (((I2C0->IF)&(1<<11))==1){} // step 7 while bushold flag in high and We still in clock streching
MS_Byte=I2C0->RXDATA; //step 8
while(((I2C0->IF)&(1<<5))==1){}//wait till recieving is complete RXDATAV will turn to 0
I2C0->CMD=I2C0->CMD|(1<<2); //send ACK to SLAVE
LS_Byte=I2C0->RXDATA; //step 9
while(((I2C0->IF)&(1<<5))==1){}//wait till recieving is complete RXDATAV will turn to 0
I2C0->CMD=I2C0->CMD|(1<<2); //send ACK to SLAVE
checksum=I2C0->RXDATA;//recieve Checksum byte
I2C0->CMD=I2C0->CMD|(1<<3); //send NACK to SLAVE
I2C0->CMD=I2C0->CMD|(1<<1); //send STOP to SLAVE
}//end step 3 end
}//end while
}//end main
