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New Contributor II


I need to externally (set high and low) control the CYSPP pin on the CYBT-323026-01 module. I am running the latest 1.2.29 EZ-Serial firmware. I understand from the EZ-Serial datasheet (, table 8-2 that the host should be able to pull this pin low in order to put the module into CYSPP mode, and then high to exit.

I am unable to override the default boot-state of the CYSPP pin using my mcu GPIO. I have the GPIO pin connected through a voltage divider to bring the voltage down from 5v->3.3v, and have set the pin output to low. This does not override the default boot state of high, and the module is not switching to CYSPP mode.

The only way I can enter CYSPP mode is to manually ground the pin, but this is not feasible for my application.

Is there an easy way to control this pin high/low?


1 Solution
New Contributor II

Thanks for your response Owen

I ended up solving this by using a transistor to ground the pin when my GPIO was set high. This has seemed to solve the problem for my purposes.

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