I have an atmega32 and a FUM DCF-U atomic clock (signal receiver and decoder) of HKW-elektronik. The µ-controller works with 5V and the module on 3.3V.
I have to build a converter, because the µ-controller only has serial-bus communication and the module has RS232 communication.
I did some research and I found these IC's: MAX232, MAX3323E or MAX3232. In the datasheets and on ArduinoSoftwareRS232 reads that it needs extra voltages (one + and one -) for some pins. Is this necessary or are the capacitors enough? And which IC should I use? (First time I need to use these IC's)
And can these IC's being used without a logic voltage converter?
Thanks in advance