On Wed, Jul 07, 2021 at 05:48:48PM -0400, Jeffrey Walton wrote: > > I'm trying to track down the cause of some garbage in a response when > > using an ELM327 (https://www.elmelectronics.com/ic/elm327/) with a > > CH341 serial controller. > > To follow up on this... > > Here's the device I am working with: OBD2 Scanner Adapter OBD2 ELM327 > USB Cable Car Code Reader Diagnostic Scan Tool v1.5, > https://www.amazon.com/gp/product/B0897G6BMZ. It has a controller for > interfacing with a vehicle's OBD II, and a CH340 for USB > communications. > > I contacted ELM Electronics Support [1] about the garbage I was > seeing. I thought I may have the serial port misconfigured in a subtle > way. Support wrote back that they did not make the OBD controller in a > v1.5. They make, among others, v1.4b and v2.0 [2]. It appears the OBD > chip is a knockoff. > > I also think I tracked down the vendor for the CH340. It is a company > called WCH. It looks like they provide a GPL'd driver for Linux [3] > and name the driver ch34x. The driver is a lot different than the one > provided by the Linux kernel [4]. > > What I don't know is, if the WCH serial controller is another > knock-off. If it is an ill-performing knock-off, then that may explain > the problems using the existing Linux driver. Using the WCH driver > probably explains why things work under Windows. The WCH driver may > fix the problems I am seeing under Linux. If you could try the latest 5.13 kernel release to let us know if that solves the issues for you or not, that would be great as a lot of work has recently gone in for these "odd" ch340-like devices. thanks, greg k-h
