Issue with JSSC and the CH340E

[wholder]

I've run into a problem when using JSSC (2.10.2) and Java 8 on a Mac Pro running Mojave and a CH340E serial adapter. The issue is that RXCHAR events get back a value of 32 when SerialPortEvent.getEventValue() is called. However, only a single byte of data was sent. I first noticed this on JSSC version 2.8.0, but it continued to happen after I switched to 2.10.2. Other USB serial adapters work fine. It just seems to be related to the CH340E. Any thoughts on what might be happening?

Wayne

[tresf]

Wayne,

Sorry about the trouble you're having. Some research on this controller and macOS suggests that the drivers on newer macOS versions should be plug-and-play, quoting: https://sparks.gogo.co.nz/ch340.html

Macintosh
(Manufacturer’s Chinese Info Link) -- broken link

First – try without drivers at all, I have heard that some macOS versions may include a driver by default.

If a driver is necessary then I belieVe the manufacturer’s v1.8 driver will cover all situations.

You must read the PDF in the zip file, how you install it differs depending on macOS Version.

Macintosh CH340 Driver V1.8 Download ZIP File

(In short, versions up to macOS 10.15 use the .pkg file, and versions macOS 11 and above use the dmg, but there are other things, READ THE PDF.

... and special uninstall directions:

Uninstalling From Macinstosh

A couple of Mac users have said “the driver crashes my mac Sierra how do I uninstall”.

Firstly regards the crash make sure you installed the 1.3 version of the driver, not the old one. You could download it directly from the Manufacturers Website in case they have issued an update since I wrote this page.

Secondly a quick google search reveals that this is how you uninstall:

1. Open a terminal and type: cd /Library/Extensions/
2. Verify that the .kext file is present: ls | grep usbserial.kext
3. Output should be: usbserial.kext
4. Then type: sudo rm -R usbserial.kext
5. Verify that the .kext file has been removed: ls | grep usbserial.kext
6. Output should be empty.
7. After you should remove the files stored in receipts folder: cd /private/var/db/receipts/
8. Find the enties: ls | grep usbserial*
9. Output should be: codebender.cc.ch34xinstaller.usbserial.pkg.bom codebender.cc.ch34xinstaller.usbserial.pkg.plist
10. Remove each one of the files of the above list: sudo rm -r filename

Sadly, all the manufacturers links seem to be broken, but they're still available on Waybackmachine. I couldn't find anything specific to the wrong byte length being returned, but I've seen so many issues with bad serial adapters that it's hard to know if this is hardware issue or driver issue.

Hopefully this information is helpful?

[tresf]

I've seen so many issues with bad serial adapters that it's hard to know if this is hardware issue or driver issue.

... perhaps baseline test on Windows (bare metal) and see what happens?