4 Replies Latest reply on Apr 27, 2017 10:45 PM by user_411084576

    psoc4 powered by UART?




      I am using a CY8CKIT-049-42xx, powered by a MINIPROG-3 at 3.3V.


      I have an UART with TX and RX that is connected to a Raspberry Pi (3.3V). TX is on P1.5, RX is on P1.4.


      As soon as I connect the RX and TX lines (and 0V) to the Raspberry, the PSoC gets powered over these lines, even if the MINIPROG is not connected. I have not yet checked if the firmware is really up and running, at least both LEDs on the CY8CKIT are on.


      When I connect the MINIPROG-3 and start debugging, the program runs fine until a character is received from the PSOC. In this case the debugger steps into UART_1_GetRxBufferSize() and never returns. It is not possible to halt the software, only stop debugging works.


      The UART is configured with 16 bytes receive buffer and 16 bytes send buffer, interrupts are enabled.


      Two questions:


      How can I avoid the PSoC to be powered over the UART connection?


      Why does the firmware get stuck in UART_1_GetRxBufferSize()?


      Any ideas are welcome.