It shows in device manager as com4, but when I try to loopback test it by shorting tx to rx, no go. When I used a simple test at picaxe for a cable test, when it was supposed to show 5 volts, it showed 0 volts. When it was supposed to show 0 it showed 3.3 volts.
The output seems inverted. What can be happening?
Can you send some photos of the board/setup? I wonder if there are any short/defects
Are you comparing with RS232? This is TTL logic and it is inverted from RS232.
It is inverted. I checked by using a laptop rs232 port and cable to a picaxe and the chip id test showed 0 at the start, an excursion to 5 volts during the test and 0 when complete.
You can’t connect an adapter like this directly to a RS232 serial port. To do that you need a TTL to RS232 converter board like a MAX3232. A better solution would be a USB to serial cable that has the converter built-in. I’ve had luck with the adapter below.
I am using this from a usb port on a pc to try to connect to a picaxe to program it which can be done with an rs232 port and a couple of resistors. It only uses 3 wires.
I was also trying to use it to connect with a PC to a Velleman VM 111 programmer board which uses various rs232 line to do what they call bit banging. Apparently it doesn’t work with anything higher tan Windows 7
Unfortunately although this does output serial, it doesn’t output RS232 serial and thats what your devices are looking for. The adapter I mentioned above should work.
