Read and write over I2C: Meaning of the parameter "ticks_to_wait"

[MajinFoo]

Hello,

i use esp-idf to write and read data over the I2C bus. To send or read data I have to call the function below:

esp_err_t i2c_master_cmd_begin(i2c_port_t i2c_num, i2c_cmd_handle_t cmd_handle, TickType_t ticks_to_wait)

Can someone explain the meaning of the parameter "ticks_to_wait"? As far as I know this function sends or writes all data in the command queue. Maybe this is a timeout parameter?

In the documentation I could only find the following information:

Parameters

• i2c_num: I2C port number
• cmd_handle: I2C command handler
• ticks_to_wait: maximum wait ticks.

[ESP_Sprite]

Yes, it is a timeout value. If the queue is full for that amount of ticks, the call aborts instead of waiting longer.

[MajinFoo]

That's already solved my question. Thanks for your reply!

[rudi ;-)]

Yes, it is a timeout value. If the queue is full for that amount of ticks, the call aborts instead of waiting longer.

hi jeroen, is it compare with clock stretching?

[ESP_Sprite]

No, it has nothing to do with clock stretching (well, maybe very indirectly); it is just the timeout for pushing things into the FreeRTOS queue in the I2C driver.

[rudi ;-)]

ah, lifetime cycle for the task?
what happens if the timeout trigger? (the call aborts)
can we repeat ? repeat count?

... ( i am not deep in this theme ) ...

best wishes
rudi