i2c call back is not getting called

[sushmasan]

Hello Team,

I am working with a DAC module (MCP47FEB21A0) that is interfaced with an LPC55S69 over I²C.

I observed that I2C_MasterTransferBlocking() works correctly, but when I use I2C_MasterTransferNonBlocking(), the I²C callback is never invoked.

I2C_MasterTransferNonBlocking() is returning kStatus_Success.

For reference, I2C_MasterTransferCreateHandle() is called once during I²C initialization.

Could someone please explain why the I²C callback is not getting called when using I2C_MasterTransferNonBlocking()?

Regards,
Santhosh

[sushmasan]

Hi @Harry_Zhang ,

I even tried it,

uint8_t txData[3] = {0};

txData[0] = (uint8_t) (reg_addr << 3);

txData[1] = (uint8_t)(data >> 8); /* Data high byte */

txData[2] = (uint8_t)(data & 0xFFU); /* Data low byte */

masterXfer.data = txData;

masterXfer.dataSize = 3; /* 3 bytes total */

I have some data which is of 2 bytes, so after the adding reg addr it becomes 3 bytes.

Still I²C callback is not getting called when I use I2C_MasterTransferNonBlocking().

Regards,

San

[Harry_Zhang]

Hi @sushmasan 

I think you can refer to the  lpcxpresso55s69_lpc_i2c_interrupt_b2b_transfer_master_cm33_core0 SDK demo.

BR

Harry

[sushmasan]

Hi @Harry_Zhang ,

Thanks for your response.

I have other sensor modules that are working with non-blocking calls.

I am using a BMP390 sensor, and the I²C communication works fine with non-blocking calls. For example, if one of the register addresses is 0x01, I assign the subaddress as shown below:

masterXfer.subaddress = (uint32_t)0x01;

However, for the DAC (MCP47FEB21A0) module, the subaddress is assigned differently:

uint8_t subAddress;
subAddress = (uint8_t)(reg_addr << 3); // Based on the MCP47FEB21A0 datasheet, the register address must be shifted left by 3
masterXfer.subaddress = (uint32_t)subAddress;

Is it going to make any difference?

Regards,
San

[Harry_Zhang]

Hi @sushmasan 

I think you can try to set subaddressSize = 0 and put the DAC’s command byte(s) and data bytes directly in masterXfer.data, then start a write transfer.

BR

Harry

[sushmasan]

Yesterday I replied to your message, but mistakenly I did a reply to the topic. I am not sure whether you have noticed it or not, that's why responding to your message again here.

Hi @Harry_Zhang ,

I even tried it,

uint8_t txData[3] = {0};

txData[0] = (uint8_t) (reg_addr << 3);

txData[1] = (uint8_t)(data >> 8); /* Data high byte */

txData[2] = (uint8_t)(data & 0xFFU); /* Data low byte */

masterXfer.data = txData;

masterXfer.dataSize = 3; /* 3 bytes total */

I have some data which is of 2 bytes, so after the adding reg addr it becomes 3 bytes.

Still I²C callback is not getting called when I use I2C_MasterTransferNonBlocking().

Regards,

San