CC2650EM-4XS-RD: M41T62 I2C controller read issue

Kiran Thupakula

Part Number: CC2650EM-4XS-RD
Other Parts Discussed in Thread: CC2650, TIMAC

Hi,

We're using TI CC2650 Wireless MCU integrated with M41T62 RTC on DIO 0 and 1 (connected to I2C SDA and SCL with driver interface initialized appropriately using HwAttr table).

We could implement the I2C transaction structure with I2C_transfer returning TRUE for both write and read transactions. But, the read buffer is 0 irrespective of what is written. Please help.

TIMAC ver: 1.5.2 & IAR Workbench IDE

Code snippet:

i2cTrans.writeCount = 2;
i2cTrans.writeBuf = txBuf;
i2cTrans.readCount = 0;
i2cTrans.readBuf = rxBuf;
i2cTrans.slaveAddress = 0x68;

i2c_ret1 = I2C_transfer(i2c, &i2cTrans);

i2cTrans.writeCount = 1;
i2cTrans.writeBuf = txBuf;
i2cTrans.readCount = 2;

i2cTrans.readBuf = rxBuf;

i2c_ret2 = I2C_transfer(i2c, &i2cTrans);

I2C_close(i2c);

Thanks

Kiran

over 5 years ago

0 Alexis Crandall20 over 5 years ago

TI__Genius 15590 points

Hi Kiran,

What is the size of your rx buffer? Where are you calling I2C_init() and I2C_open()? Have you tried treating these as two different transactions with two different transaction structures? Are you using blocking mode or callback mode?

Thanks,

Alexis

0 Alexis Crandall20 over 5 years ago in reply to Alexis Crandall20

TI__Genius 15590 points

Hi Kiran,

I haven’t heard back from you, hence this issue is being closed. If you wish to continue the discussion, please post a reply with an update below (or create a new thread).

Thanks,

Alexis

0 Kiran Thupakula over 5 years ago in reply to Alexis Crandall20

Prodigy 30 points

Hi Alexis,

The issue was fixed after using the Blocking mode. I haven't explored further on why it was not working on Callback mode.

Thanks

Kiran

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CC2650EM-4XS-RD: M41T62 I2C controller read issue