The more I try to connect to old serial devices with an Arduino, the more I realise the inadequacies of the devices I have been trying to use.
The MAX3232 adaptor has only got RX, TX GND and VCC, no CTS, RTS, DTR or DSR - I cannot find another level changing adaptor with DB9 socket or plug on it.
Most device I have been trying with seem to need CTS or some form of hardware handshaking.
Does anyone know of a decent, not too expensive adaptor board that will allow me to get TTL out of an old Serial device?
Or what is the accepted method of reading data from a +12/-12v RS232 device with CTS and RTS?
The MAX232 and MAX3232 both support 2 inputs and outputs. Some of the modules go for cheap and only bring out 1 each for TX and RX, others bring out the other 2 which can be used for handshake lines.
Does anyone know a proper answer to this, if there exists an adaptor or breakout board, that supports all RS232 devices, that is uses all pins on the DB9 side, allowing RX, TX GND, VCC, CTS, RTS, DTR, DSR and RI - and converts them to TTL, and back correctly?
I'd just roll one using a few MC1488 and/or mC1489, or MAX232, or whatever's on the shelf. Moving into this century, it looks like, for simplicity, what you want is a device based on a MAX3237 or MAX3241, depending upon whether you want DTE or DCE.
Didn't find one in a cursory search of Amazon and AliExpress.
Looks like the best solution might be to buy a few ICs and roll your own, if you have the skillset.
You should not need all of the handshaking connections. DTR/DSR/DCD are to establish if a remote device is actually present. If you can see they are you dont need those.
Vcc is not present
