CC2541 I2C Communication Problem

krishna narayanan

Other Parts Discussed in Thread: CC2541

Hi,

i am trying to connect Gyroscope (L3GD20) with CC2541 through I2C communication. Im using TI Keyfob Sample program for the same but unfortunately i am not able to establish communication with the device. i have checked the clock pulse in DSO and got the correct clock pulse (33 kHz frequency) and no clock pulses for data were detected on DSO.

My basic problem is that my code was not able to establish I2C communication with the device. I have checked with only I2C start condition but i am not able to receive acknowledgement from the device that means communication link was not established. Checked with all connections and program as well but unfortunately the result is same. can some one please help me to sort out this issue.

Thanks in advance

over 12 years ago

0 Sarang Mandke over 12 years ago

TI__Prodigy 260 points

Please refer to this thread -

http://e2e.ti.com/support/low_power_rf/f/538/t/172539.aspx

0 krishna narayanan over 12 years ago in reply to Sarang Mandke

Expert 1190 points

Hi Sarang,

We tried doing the same methods as mentioned in the link but unfortunately the result remains the same.

we are not able to establish basic I2C communication link. we tried to capture SCL and SDA from the ports on CC2541 with out any slave connected(attaching the same for your reference). But with the slave connected, we are not able to recieve any acknowledgement from the slave after start condition.

will forward you our code if in case needed for further reference

Thanks in advance

Regards

0 krishna narayanan over 12 years ago in reply to krishna narayanan

Expert 1190 points

Hi Sarang,

please refer to the I2C code that we have implemented for our slave Gyro and let me know if any corrections to be done for establishing basic I2C communication link.

#include<ioCC2541.h>

#define BV(n) (1 << (n))

typedef unsigned char u8_t;
typedef unsigned short int u16_t;
typedef short int i16_t;
typedef signed char i8_t;

#define I2C_ENS1 BV(6)
#define I2C_STA BV(5)
#define I2C_STO BV(4)
#define I2C_SI BV(3)
#define I2C_AA BV(2)

#define RESET P0_6
#define led1 P1_0
#define led2 P1_1

#define I2C_SR 0xE0
#define I2C_SP 0xD0
#define I2C_DO 0xC0

#define CLKCON_OSC32K 0x80 // 32 kHz clock source select/status
#define CLKCON_OSC 0x40 // system clock source select/status
#define CLKCON_TICKSPD (0x07 << 3) // bit mask, global timer tick speed divider
#define CLKCON_TICKSPD_32M (0x00 << 3)
#define CLKCON_TICKSPD_16M (0x01 << 3)
#define CLKCON_TICKSPD_8M (0x02 << 3)
#define CLKCON_TICKSPD_4M (0x03 << 3)
#define CLKCON_TICKSPD_2M (0x04 << 3)
#define CLKCON_TICKSPD_1M (0x05 << 3)
#define CLKCON_TICKSPD_500K (0x06 << 3)
#define CLKCON_TICKSPD_250K (0x07 << 3)
#define CLKCON_CLKSPD (0x07) // bit mask for the clock speed division
#define CLKCON_CLKSPD_32M (0x00)
#define CLKCON_CLKSPD_16M (0x01)
#define CLKCON_CLKSPD_8M (0x02)
#define CLKCON_CLKSPD_4M (0x03)
#define CLKCON_CLKSPD_2M (0x04)
#define CLKCON_CLKSPD_1M (0x05)
#define CLKCON_CLKSPD_500K (0x06)
#define CLKCON_CLKSPD_250K (0x07)

#define L3G4200D_OUT_X_L 0x28
#define L3G4200D_OUT_X_H 0x29
#define L3G4200D_OUT_Y_L 0x2A
#define L3G4200D_OUT_Y_H 0x2B
#define L3G4200D_OUT_Z_L 0x2C
#define L3G4200D_OUT_Z_H 0x2D

typedef enum {
X_AXIS =0x01,
Y_AXIS =0x02,
Z_AXIS=0x03
} axis;

void i2c_init();
void gyro_start();
void gyro_stop();
void gyro_send(unsigned char x);
void gyro_write(unsigned char reg,unsigned char dat);
unsigned char gyro_receive(unsigned char reg);
void gyro_init();
void delay(unsigned char n);
void timer_delay(unsigned char m);

******************************************************************************************

#include<ioCC2541.h>
#include<gyro.h>
void gyro_start()
{
I2CCFG &=~I2C_SI;
I2CCFG |=I2C_STA;
while((I2CCFG&I2C_SI)==0);
I2CCFG &=~I2C_STA;
}
void gyro_stop()
{
I2CCFG &=I2C_STO;
I2CCFG |=~I2C_SI;
while((I2CCFG&I2C_STO)!=0);
}
void gyro_send(unsigned char x)
{
I2CDATA = x;
I2CCFG &= ~I2C_SI;
while ((I2CCFG & I2C_SI) == 0);
}

unsigned char gyro_read()
{
I2CCFG &= ~I2C_SI;
while ((I2CCFG & I2C_SI) == 0);
return I2CDATA;
}

void gyro_write(unsigned char reg,unsigned char dat)
{
I2CCFG=I2C_SR;

I2CDATA=0xD4;
I2CCFG=I2C_DO;

I2CDATA=reg;
I2CCFG=I2C_DO;

I2CDATA=dat;
I2CCFG=I2C_DO;

I2CCFG=I2C_SP;

}
unsigned char gyro_receive(unsigned char reg)
{
I2CCFG=I2C_SR;

I2CDATA=0xD4;
I2CCFG=I2C_DO;

I2CDATA=reg;
I2CCFG=I2C_DO;

I2CCFG=I2C_SR;

I2CDATA=0xD5;
I2CCFG=I2C_DO;

I2CCFG=I2C_DO;

I2CCFG=I2C_SP;

return I2CDATA;
}
void i2c_init()
{

//I2CCFG=0x45;
I2CWC = 0x00;
}
void gyro_init()
{
gyro_write(0x20,0x0F);
gyro_write(0x21,0x29);
gyro_write(0x22,0x80);
gyro_write(0x23,0x20);
gyro_write(0x32,0x2C);
gyro_write(0x33,0xA4);
gyro_write(0x34,0x2C);
gyro_write(0x35,0xA4);
gyro_write(0x36,0x2C);
gyro_write(0x37,0xA4);
gyro_write(0x38,0x00);
gyro_write(0x30,0x2A);
}

i16_t L3G4200D_GetAngRateRaw(axis a)
{
u8_t valueL;
u8_t valueH;
u16_t value;
switch (a)
{
case X_AXIS:
valueL=gyro_receive(L3G4200D_OUT_X_L);

valueH=gyro_receive(L3G4200D_OUT_X_H);

value = (i16_t)( (valueH << 8) | valueL );
break;
case Y_AXIS:
valueL=gyro_receive(L3G4200D_OUT_Y_L);

valueH=gyro_receive(L3G4200D_OUT_Y_H);

value = (i16_t)( (valueH << 8) | valueL );
break;
case Z_AXIS:
valueL=gyro_receive(L3G4200D_OUT_Z_L);

valueH=gyro_receive(L3G4200D_OUT_Z_H);

value = (i16_t)( (valueH << 8) | valueL );
break;
}
return value;
}

i am also attaching the schematic for your reference

6607.CC2541 Keyfob with GYRO.pdf

A quick reply for this problem will be really helpful for us as we are running out of time

Thanks in advance

Regards,

Krishna

0 Sarang Mandke over 12 years ago in reply to krishna narayanan

TI__Prodigy 260 points

I am assuming that CC2541 is the Master here.

1) Please check if SDA and SCL pullup enable needs to be set in I2CWC, depending on your schematic

2)I guess you already said you get 33 KHz., but please check I2CCFG

3)Ensure that during init you have the following line of code -I2CCFG |= (I2C_ENS1 | I2C_AA)

4) After you send start condition, manually clear the STA bit, after the wait for SI ends.

5) Check I2CSTAT to ensure you read a "Start transmitted" before you write the slave's address

6) Write slave address to I2CDATA

7)Start writing data to the slave, for every byte you should see I2CSTAT.STAC = 0x28 which means ACK received.

0 krishna narayanan over 12 years ago in reply to Sarang Mandke

Expert 1190 points

Hi Sarang,

Thanks for the quick reply

yes you are right, CC2541 is our master device

we had followed all points mentioned by you but once again we will try doing all the points mentioned by you for confirmation.

will post you the result once i have done with all the above mentioned solutions

Regards,

Krishna

0 krishna narayanan over 12 years ago in reply to krishna narayanan

Expert 1190 points

Hi Sarang,

we made the I2C communication link working on the device with your valuable suggestions

Once again thanks for your help

Regards,

Krishna

0 krishna narayanan over 12 years ago in reply to krishna narayanan

Expert 1190 points

Hi Sarang,

I need more help from you regarding the same I2C communication with another slave(OLED) ssd1306.

we have been testing our OLED(Slave)to Display via I2C with CC2541 by checking acknowledgements for each commands, we are able to receive acknowledgement from slave till Display offset command. we got stuck at Display Offset command and not going further. We tried and got acknowledgement after Display_Offset (0xD3) but after writing no offset command (0x00),no acknowledgement was received and not going further and same case with Normal Display(0xA6) and Inverse Display Commands(0XA7).

For the same controller, we are able to communicate with other I2C slave(Gyro) perfectly but in this case communication was not happening with OLED.

I am also posting the updated code, please kindly check and help us in getting the issue sorted out at the earliest.
Eagerly waiting for your reply

#include<ioCC2541.h>
#include<oled.h>

unsigned char logo1[4][132] =
{
{0x00,0x00,0x00,0x00,0x00,0x80,0xC0,0xE0,0xF0,0xF8,0x0C,0x06,0x03,0x01,0x03,0x06,0xCC,0xE0,0xF0,0xF8,0xFC,0x06,0x03,0x01,0x03,0x06,0x0C,0xF8,0xF0,0xE0,0xC0,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xC0,0xC0,0xC0,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
{0x00,0x00,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0x00,0xB6,0xB6,0xB6,0xB6,0xB6,0xB6,0xB6,0xB6,0xB6,0xB6,0xB6,0xB6,0xB6,0x00,0x00,0xE0,0xF8,0x38,0x1C,0x1C,0x1C,0x3C,0x78,0xF0,0xC0,0x00,0x00,0x7C,0xFC,0xC0,0x00,0x00,0x00,0x00,0x00,0xF1,0xFF,0x1F,0x7C,0xE0,0x00,0x00,0x00,0x30,0x38,0x1C,0x8C,0xCC,0xF8,0xF0,0x00,0x00,0x78,0xFC,0x0C,0x0C,0x00,0x78,0xFC,0xCC,0x8C,0x98,0xFC,0xFC,0x00,0x00,0x3C,0xFC,0xC0,0x00,0x7C,0xFC,0xC0,0x00,0x00,0xF0,0xF8,0x1C,0x0C,0x0C,0x1C,0x38,0xF0,0xC0,0x00,0x7C,0xFC,0xC0,0x00,0x00,0x00,0x3C,0xFC,0xC0,0x00,0x78,0xFC,0x0C,0x0C,0x00,0x1C,0x3C,0x7C,0xCC,0x8C,0x0C,0x0C,0x00,0x00,0x00},
{0x00,0x00,0x7F,0x7F,0x7F,0x7F,0x7F,0x7F,0x7F,0x7F,0x7F,0x7F,0x7F,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0x00,0x6D,0x6D,0x6D,0x6D,0x6D,0x6D,0x6D,0x6D,0x6D,0x6D,0x6D,0x6D,0x6D,0x00,0x00,0x1F,0x7F,0xF0,0xC0,0x80,0x80,0x80,0x80,0xC0,0xF0,0x30,0x00,0x00,0x3F,0x3F,0x0C,0x18,0x38,0x20,0x00,0x3F,0x3F,0x00,0x00,0x03,0x1F,0x3C,0x20,0x00,0x0F,0x1F,0x33,0x31,0x31,0x38,0x18,0x00,0x30,0x3F,0xFC,0xB0,0x30,0x00,0x0C,0x1C,0x31,0x31,0x31,0x3F,0x1F,0x00,0x00,0x7F,0xFF,0x80,0x30,0x7F,0xFF,0xB0,0x30,0x07,0x0F,0x1C,0x38,0x30,0x30,0x38,0x1F,0x07,0x00,0x00,0x3F,0x3F,0x0C,0x10,0x30,0x30,0x3F,0x1F,0x00,0x30,0x3F,0xFC,0xB0,0x30,0x00,0x30,0x30,0x31,0x33,0x3E,0x3C,0x38,0x00,0x00},
{0x00,0x00,0x00,0x00,0x00,0x01,0x03,0x07,0x0F,0x1F,0x30,0x60,0xC0,0x80,0xC0,0x60,0x33,0x07,0x0F,0x1F,0x3F,0x60,0xC0,0x80,0xC0,0x60,0x30,0x1F,0x0F,0x07,0x03,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x03,0x03,0x03,0x03,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x03,0x03,0x00,0x00,0x01,0x03,0x03,0x03,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
};

unsigned char logo2[4][132] =
{
{0x00,0xF8,0x00,0x00,0x00,0xF8,0x00,0x00,0xF8,0x08,0xF8,0x08,0xFF,0x10,0x08,0x18,0xF0,0x00,0x00,0x08,0x00,0x38,0xC0,0x00,0x38,0xC0,0x00,0xE0,0x18,0xE0,0x00,0xE0,0x18,0xE0,0x00,0xE0,0x18,0xE0,0x00,0xE0,0x18,0xE0,0x00,0xE0,0x18,0xE0,0x00,0xE0,0x18,0xE0,0x00,0x00,0x08,0x00,0xF0,0x08,0x08,0x30,0x00,0xF8,0x00,0x00,0x00,0x01,0xE1,0x1E,0xE0,0x00,0x00,0x30,0x88,0x88,0x70,0x00,0xF8,0x08,0x30,0x48,0x48,0x90,0xF8,0x00,0xF8,0x00,0xF8,0x00,0xF0,0x18,0x08,0x18,0xF0,0x00,0xF8,0x00,0x00,0x00,0xF8,0x00,0xF8,0x08,0x18,0x68,0x88,0x08,0x00,0x00,0x08,0x00,0xF0,0x08,0x08,0x30,0x00,0xF0,0x18,0x08,0x18,0xF0,0x00,0x00,0xF8,0x00,0x00,0xF8,0x00,0x00,0xF8,0x00},
{0x00,0x3F,0x02,0x04,0x04,0x03,0x00,0x04,0x3F,0x04,0x3F,0x04,0x07,0x02,0x04,0x06,0x03,0x00,0x00,0x04,0x00,0x00,0x03,0x3C,0x00,0x03,0x3C,0x07,0x00,0x01,0x06,0x01,0x00,0x07,0x00,0x07,0x00,0x01,0x06,0x01,0x00,0x07,0x00,0x07,0x00,0x01,0x06,0x01,0x00,0x07,0x00,0x00,0x00,0x00,0x03,0x04,0x04,0x03,0x00,0x07,0x02,0x04,0x00,0x06,0x01,0x00,0x01,0x06,0x00,0x03,0x04,0x04,0x02,0x04,0x3F,0x04,0x03,0x04,0x04,0x04,0x03,0x00,0x3F,0x04,0x3F,0x24,0x03,0x06,0x04,0x06,0x03,0x00,0x07,0x02,0x04,0x04,0x03,0x04,0x3F,0x04,0x04,0x04,0x05,0x06,0x00,0x00,0x00,0x00,0x03,0x04,0x04,0x03,0x00,0x03,0x06,0x04,0x06,0x03,0x00,0x00,0x07,0x04,0x04,0x07,0x04,0x04,0x03,0x00},
{0x00,0xF0,0x0C,0x02,0x02,0x02,0x0C,0x30,0x00,0x00,0x00,0xFE,0x00,0x00,0x00,0x00,0x00,0x00,0x0E,0xF0,0x40,0x40,0x40,0xF0,0x0E,0x00,0x00,0xFE,0x02,0x02,0x02,0x02,0x00,0x00,0x00,0x00,0x00,0xFE,0x00,0x00,0x00,0x00,0x06,0x1A,0x22,0xC2,0x82,0x02,0x00,0x00,0xF8,0x86,0x02,0x02,0x86,0xF8,0x00,0x00,0x18,0x04,0x02,0x02,0x84,0xF8,0x00,0x00,0x06,0x1A,0x22,0xC2,0x82,0x02,0x00,0x00,0x00,0xFE,0x02,0x02,0x02,0x02,0x0C,0xF0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x18,0x06,0x02,0x82,0x46,0x3C,0x00,0x00,0x00,0xF8,0x46,0x42,0x46,0xCC,0x00,0x00,0x00,0xFE,0x00,0x00,0x00,0x00,0xFE,0x00,0x00,0x00,0xF8,0x46,0x42,0x46,0xCC,0x00,0x00,0x8C,0x42,0x42,0x22,0x3C,0x00},
{0x00,0x0F,0x30,0x40,0x40,0x40,0x20,0x18,0x00,0x00,0x00,0x7F,0x41,0x41,0x41,0x41,0x40,0x00,0x00,0x01,0x3F,0x40,0x3E,0x01,0x00,0x00,0x00,0x7F,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x18,0x30,0xFF,0x00,0x00,0x00,0x00,0x30,0xC0,0x80,0x80,0xC3,0x3E,0x00,0x00,0x3E,0xC3,0x81,0x81,0x43,0x3E,0x00,0x00,0x60,0x80,0x81,0x81,0xC3,0x3C,0x00,0x00,0x30,0xC0,0x80,0x80,0xC3,0x3E,0x00,0x00,0x00,0x7F,0x40,0x40,0x40,0x40,0x30,0x0F,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x3E,0x61,0x41,0x40,0x60,0x18,0x00,0x00,0x00,0x01,0x06,0x04,0x06,0x01,0x00,0x00,0x00,0x07,0x03,0x06,0x00,0x00,0x47,0x00,0x00,0x00,0x01,0x06,0x04,0x06,0x01,0x00,0x00,0x03,0x04,0x04,0x04,0x03,0x00},
};

void oled_start()
{
I2CCFG &=~I2C_SI;
I2CCFG |=I2C_STA;
while((I2CCFG&I2C_SI)==0);
I2CCFG &=~I2C_STA;
}
void oled_stop()
{
I2CCFG &=I2C_STO;
I2CCFG |=~I2C_SI;
while((I2CCFG&I2C_STO)!=0);
}
void oled_send(unsigned char x)
{
I2CDATA = x;
I2CCFG &= ~I2C_SI;
while ((I2CCFG & I2C_SI) == 0);
}

unsigned char oled_read()
{
I2CCFG &= ~I2C_SI;
while ((I2CCFG & I2C_SI) == 0);
return I2CDATA;
}

void oled_command(unsigned char cmd)
{
I2CCFG=I2C_SR;
wait_ack(SR_SENT); //start_ack

I2CDATA=0x78;
I2CCFG=I2C_DO;
wait_ack(SLAW_ACK_SENT); //slave address+W ack

I2CDATA=0x00;
I2CCFG=I2C_DO;
wait_ack(DATA_ACK_SENT); //data sent ack

I2CDATA=cmd;
I2CCFG=I2C_DO;
wait_ack(DATA_ACK_SENT); //data sent ack
led1=1;
led2=0;

I2CCFG=I2C_SP;

}
void oled_data(unsigned char dat)
{
I2CCFG=I2C_SR;
wait_ack(SR_SENT); //start_ack

I2CDATA=0x78;
I2CCFG=I2C_DO;
wait_ack(SLAW_ACK_SENT); //slave address+W ack

I2CDATA=0x40;
I2CCFG=I2C_DO;
wait_ack(DATA_ACK_SENT); //data sent ack

I2CDATA=dat;
I2CCFG=I2C_DO;
wait_ack(DATA_ACK_SENT); //data sent ack

I2CCFG=I2C_SP;

}
void i2c_init()
{

I2CCFG=I2C_DO;
I2CWC |= ~0x80;
}
void oled_init()
{
RESET=0;
delay(128);
RESET=1;
delay(128);
/**oled_command(0xAE);
oled_command(0xD5);
oled_command(0x80);
oled_command(0xA8);
oled_command(0x1F);
oled_command(0xD3);
oled_command(0x00);
oled_command(0x40);
oled_command(0x8D);
oled_command(0x14);
oled_command(0xA1);
oled_command(0xC8);
oled_command(0xDA);
oled_command(0x02);
oled_command(0x81);
oled_command(0xCF);
oled_command(0xD9);
oled_command(0xF1);
oled_command(0xDB);
oled_command(0x40);
oled_command(0xA4);
oled_command(0xA6);
oled_command(0xAF);***/
oled_command(0xAE);//--Set Display off

led1=0;
led2=1;

oled_command(0x00);//--set low column address

oled_command(0x10);//--set high column address

oled_command(0x81);//--set contrast control register
oled_command(0x7f);

oled_command(0xa1);//--set segment re-map 95 to 0

oled_command(0xA6);//--set normal display

oled_command(0xa8);//--set multiplex ratio(1 to 16)
oled_command(0x1f);//--duty 1/32

oled_command(0xd3);//--set display offset
oled_command(0x00);//--not offset

oled_command(0xd5);//--set display clock divide ratio/oscillator frequency
oled_command(0xf0);//--set divide ratio

oled_command(0xd9);//--set pre-charge period
oled_command(0x22);

oled_command(0xda);//--set com pins hardware configuration
oled_command(0x02);//disable left/right remap and set for sequential

oled_command(0xdb);//--set vcomh
oled_command(0x49);//--0.83*vref

oled_command(0x8d);//--set DC-DC enable
oled_command(0x14);//

oled_command(0xAF);//--turn on oled panel

oled_command(0xA4);//--Entire Display ON

timer_delay(100);
}

void delay(unsigned char n)
{
while(n--)
asm("nop");
}
void timer_delay(unsigned char m)
{
unsigned char i;
T3CTL|=0x10;
for(i=0;i<m;i++)
{
while((TIMIF&0x01)==0);
T3OVFIF=0;
}
}

void show_bitmap(unsigned char bitmap)
{
unsigned char j=0;
unsigned char i=0;

for(i=0;i<8;i++)
{
oled_command(0x00); //lower column address
oled_command(0x10); //upper column address
oled_command(0xB0+i); //set page address
for(j=0;j<128;j++)
{
if(bitmap==0)
{
led1=0;
led2=1;
oled_data(logo1[i][j]);
}
else
{

oled_data(logo2[i][j]);
}
}
}
}

void wait_ack(unsigned char ack)
{
while(I2CSTAT!=ack);
}

Regards,
Krishna.

0 krishna narayanan over 12 years ago in reply to krishna narayanan

Expert 1190 points

Hi Sarang,

An important addition to the above query, as we are getting stuck at no offset command which is 0x00, whether it might be causing problem in communicating with the device.

If in that case any solution regarding that command that helps in getting communication work will be very helpful for us.

Thanks& Regards,

Krishna.

0 ming li51 over 10 years ago in reply to krishna narayanan

Prodigy 130 points

hi,Krishna
i am doing the ssd1306 oled, i meer the problem the same as you,hou do you solve the problem? can you give some code. liming1837534@gmail.com

Regards,
Liming

0 user4755463 over 9 years ago in reply to krishna narayanan

Prodigy 30 points

I encountered a problem now. I followed your code , and exectued, bu it was blocked at the code
wait_ack(SR_SENT);
I'm also using CC2541 as a master, and the slave is MPU9250, I write it as a barehardware.
I had checked the hardware, it's ok. I was confused by this questions a few days. Can you give me some questions?

Thanks！

0 user4755463 over 9 years ago in reply to krishna narayanan

Prodigy 30 points

Hi Krishna,
Now I use CC2541 as a master, and the slave is MPU9250. It was blocked at wait_ack(SR_SENT); //start_ack;
The hardware was connected correctly, I was confused by this question some time. Can you give me some questions? I 'm just writing a baremachine.

Thans & Best Regards
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CC2541 I2C Communication Problem