I am developing a board where the RS232's RTS signal is used to force a reset to the MPU in order to upload the code.
I am using a MAX232 chip for the { RX, TX, RTS} signals
RX_232 ---MAX232--- RX_TTL
TX_232 ---MAX232--- TX_TTL
RTS_232 ---MAX232--- RTS_TTL -----------> N-MOS ---> /Reset
Measuring the volt at the RTS_TTL pin, I see it's
0V during a Minicom session
5V on the Linux bash, before launching Minicom
So this causes the target to have unwanted resets.
I can hack Minicom and invert the logic, but I'd prefer to modify the Linux behavior in order to have the same behavior of Minicom for the RTS signal.
How to do it? Should I have to hack the RS232 kernel module? Or is there something I can do in user-space.
Thanks
edit: mistake fixed
RTS and DTR are output pins,
DCD and CTS are input pins and can only be read.