Electrical – Convert TTL levels to RS232 of FTDI USB<->Serial

communicationftdilevelserialttl

Have this small interface FTDI FT232RL to connect a Serial device to the computer via USB.

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It has been working well for most of my Serial applications, except today when I tried to use it for a Roboteq controller. While all settings are correct, characters are garbage.

The support tells me the FTDI device use TTL levels (0~3.3/5V) instead of RS232 (-9~+9V). Which seems to be unfortunately correct according to the FTDI doc.

Question

Is there a simple way to have this FTDI device consider RS232 levels, not TTL? (eg like shorting a couple of pins) The Roboteq device doesn't seem to be configurable in this regard.

Best Answer

If you want to talk over USB it would be far faster and easier to just buy one of the many USB->RS232 converter cables than to mess around making that into one. I've seen them for as low as $7 USD online.

There are even cables with the FTDI chips in them so if you've been using the D2XX library you can continue doing so.

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