MQX4.1.1 I2C example program ran into problem，need help.

[tongjianwu]

Hello everyone,

When I use the example program for I2C located in <install_dir>\Freescale\Freescale_MQX_4_1\mqx\examples\i2c,I found the program stop at "result = fwrite (mem, 1, 1, fd);"

The E2PROM type is 24C02.

   mem[0] = (uint8_t)addr;
   printf ("  Write to address 0x%02x ... ", mem[0]);
   do 
   {
      result = fwrite (mem, 1, 1, fd);
      printf("\r\n Hello World \r\n");
   } while (result < 1)

Need help,thks!

[tongjianwu · Accepted solution]

Hello every one ,

          I have made a mistake,the I2C device address in MQX should be below format:

          for example, AT24C02, addr = 1 0 1 0 A2 A1 A0 R/W，this should be shift right one bit (addr>>1),then this parameter pass to MQX I2C driver .

          Thks !

Best Regards!

[poul-erikhansen]

I see problems that the driver hangs.
I think it's easiest to modify the polled version.
The drivers in MQX are no specific stable or well written.

Best regards Poul-Erik.

.

[tongjianwu]

Thks for your reply,

     so what should I do for this problem?

     before that, I test the I2C driver for ACCELEROMETER, the program run normally.

     after that I test the program for my specific E2PROM,I ran into problems.

Best regard

[poul-erikhansen]

What we have seen is long time stability problems. We use a 24C128 + some IO port expanders, and it works most of the time. I You can't get it working for the first time, You shod use a logic analyzer or a osciloscop.

Best regards.

[tongjianwu]

Hello,Poul-Erik.

          Can you offer me the E2PROM Demo code?

          Thks!

Best Regards!

[tongjianwu]

Just now,I test the program for at24c02 and find that " I2C start, send address and get ack ... OK ... ack ==1".

The ACK ought to be '0',now I get ACK=1, I think this is the problem here.

[soledad]

Hello Tong,

Yes you are right, please check the below thread.

[MQX 4.1]I2C demo for MMA8451Q

Have a great day,
Sol

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[tongjianwu]

Hello,soledad.

          I have seen the code for ACCELEROMETER and used for TWR_K70F120M,the program run normally,when I use it for E2PROM,there is NACK for sending slave device address byte.

          I use external E2PROM connected to  TWR_K70F120M's I2C0 channel for testing,I don't know why this happen.

          Thks!

Best Regard!