Many customers have faced the issue of not being able to program TCA6424A.
Their requirement varies from "setting a pin to output mode or High state" to "setting a pin to input mode or LOW state".
The schematic below shows TCA6424A and there is a requirement to modify the state or the direction of one or more than one pins out of 24 available.
The first method would be to use the TCA6424 drivers provided by TI. This is documented in MCU PLUS SDK and can be found in the Relevant Links section above.
We will make use of SoC_I2C1 to play with the TCA6424 drivers provided by TI.
The entire procedure can be wrapped up in 6 simple steps. These steps are very easy to understand.
The second approach will make use of the I2C transaction parameters and the API I2C_tansfer() to get the job done.
This has been explained in a 3 step process which is easy to understand.
Here is the explanation for choosing index value as 14 in TCA6242_config() and TCA6424_output API().
In the earlier explanation we are configuring Port-16 in the output mode, for this we call the TCA6242_config() API with index parameter as 14.
TCA6424_config(&tcaConfig, 14, 1), where tcaConfig is the configuration object, 14 is the index, 1 is the output mode.
From the datasheet we can see that the ports are numbered from Port[0:7], Port[10:17] & Port[20:27] which means the index for Port10 will be 8 instead of 10.
Similarly for Port20 the index value is 16 and so on.
| Port Number | Index Number |
| 0-7 | 0-7 |
| 10-17 | 8-15 |
| 20-27 | 16-23 |
Please refer below image from TCA6424 datasheet.
Regards,
Tushar
