How to connect baby orangutan to RS232 port

I working to send a command to the microcontroller (baby orangutan 328p) using Wifi to control a motor. The wifi module I used has an RS232 cable which as I expect to be connected to the microcontroller ( data are already level shifted). I connected DB9 connector pins: TXD to Rx of the microcontroller and the GND but still there are 7 pins left and I do not know what to connected and to which pins of the microcontroller, any one have an idea about the connection.

Note I did not connect RXD to Tx of the microcontroller because I don’t send any data, but do I have to connect it ??

I will really appreciate any help.


Hello, Alia.

The Pololu AVR C/C++ Library only supports RX and TX, so you shouldn’t connect any of those other signals to your Baby Orangutan yet. You should read the documentation of your Wifi module to see if you actually need to use any of those other signals.

You do not need to connect the Baby Orangutan’s TX if you don’t plan on sending anything from the Baby Orangutan.

Are you sure the voltage levels in your DB9 cable have been shifted to 0-5 V? Normal RS-232 voltage levels can permanently damage microcontrollers, so it’s good to double check.