RS232 dongle

Has anyone made an RS232 dongle?

What I mean is a device in a case, with a RS232 9-pin d connector one side, an imp the other and ideally a USB psu.

I experimented with sending data from my imp to my old TRS-80 Model 200 computer using the RS232 port. It worked good. I was able to communicate both directions just fine.

You should (or I would say ‘must’) use this chip to interface between the imp and the RS-232:

You can actually buy the assembly (with pump capacitors installed) here:

Here’s another assembly I did not try:

It handles the conversions of the 3.3V to whatever your RS232 is … otherwise, you’ll burn out pin 1 of your imp.

Type this into Google, and view Google Images: max3232 example circuit

That will give you some example circuits. Not the imp, but you’ll get the idea.

looks cool,

looking at those ready made boards, with just the addition of an april and a 3d printed case I could have what I was looking for.


We have a reference design for this coming out, fits an off the shelf case quite nicely. Not sure when it’ll be posted, but it’s complete and works nicely…

great, I think theres a real opportunity there to make everything that has a rs232 port “connected”

I also see uses for RS485, Modbus, and various industrial applications. Some people use digital pyrometers (ramp/soak temp controllers) for kilns. Many of those come with RS485/Modbus communications. It would be great to create some apps with temperature ramp profiles and store recipes for different things used.

There’s already an RS485 reference design, see