Back in the dayswhen PCs came with serial and parallel ports, techs had sets of plugs to test the serial and parallel interfaces with.
There is also a >>>video<<< on this!
TodayI still use a RS232 adapter on my SurfacePro at work to configure Cisco network components. I had quite a few of these for the last few years with different chip sets.
For my microcontroller hacking joy, I have come to like CP2102 based adapters like this one. The chip is 5V tolerant and puts out 3.3V levels which is good enough for 5V applications, too.
Put it to the testSometimes, when stuff doesn't work as expected, I wonder: Does my USB-serial adapter even work? And the test is easy:
Now everything transmitted through the TXD pin is fed back to the receive pin.
If the driver installed ok, you will see a new COM Port. In this case: COM3
For the loopback test, you have to configure that COM-Port into Putty:
If you see what you type, everything is ok:
|No local echo|
If you enable local echo (tick "Force on"),
|Enable or disable local echo|
|With local echo|
Materials used in the video and for the blog entry:
- CP2102 usb serial adapter
- Jumper cables
- 9V rechargeable lithium battery
- Oscilloscope (Kit)
- 9V Clip/Connector
- Putty Terminal Software (free)