A neat and elegant solution, and a cool little tool. Note that there is supposedly also: make flash ESPPORT=... ESPBAUD=... to override the menuconfig setting. Regards, Mark. P.S. I avoid this by ensuring I only plug in one at a time ;-)
On 19 Feb 2018, at 9:18 AM, Stephen Casner <casner@acm.org> wrote:
Perhaps none of you (other than Mark) have multiple OVMS v3 devices to connect to your computer. I have an OVMS v3.0 plus a smaller DEVKIT-C module that Mark sent to me to begin the infrastructure work before the developer boards were available. I want to run some other code on the DEVKIT-C module, so I plugged it into my Mac laptop via the same powered hub that I bought to support the OVMS v3.0 board.
I discovered that the driver for the Silicon Labs CP2102 USB-to-UART bridge controller assigns a device name like /dev/tty.SLAB_USBtoUART19 to the second device that is connected. The number 19 represents how many times one of these devices has been connected, so if I unplug the second device and plug it back in again its device name will change to /dev/tty.SLAB_USBtoUART20. Since that device name is configured into sdkconfig that means a reconfig and full rebuild each time I need to unplug! Bah.
So I went searching on the Silicon Labs forum and found that a support request to do something more sane was filed three years ago and has yet to be addressed. But one post included a workaround which is to use a python script to scan the system information about the USB hierarchy to find the location ID corresponding to each of these device names. The location ID of the port where the device is plugged in remains constant. Depending upon how the devices are being used, that can allow using a script to learn the device name currently assigned to each of the physical devices (assuming that a given physical device is always plugged into the same port).
I took this idea and modified components/esptool_py/Makefile.projbuild to invoke an added program tools/findcp2102.py to look up the serial port as a location ID and translate it to the current device name. For example, in the sdkconfig file in my work tree for the DEVKIT-C I have changed CONFIG_ESPTOOLPY_PORT="20-2.1" which (currently) gets translated to /dev/tty.SLAB_USBtoUART20 when I run make (or make flash or make monitor).
If the tools/findcp2102.py program is run with no argument it will list the location ID and device name for all the connected CP2102 devices. I can know which device name belongs to each physical device according to the order in which I plugged them in, so that gives me the associated location ID. It is also possible to see these location IDs in the Mac's System Report, but the numbering scheme is different.
I've committed this change to the openvehicles/esp-idf repository. The change is implemented such that is has no effect if the serial port spec is not found as a USB location ID, so it should cause no harm.
-- Steve _______________________________________________ OvmsDev mailing list OvmsDev@lists.teslaclub.hk http://lists.teslaclub.hk/mailman/listinfo/ovmsdev