Is there a way to specify which teensy is programmed via its serial number?

[hmaarrfk]

For use cases where we have multiple teensies connected, is it possible to specify which one we program via their serial number? usb port?

[takurx]

Hi @hmaarrfk, I also want to write to multiple teensy (same version, 3 teensy 4.1s). When it open Teensy, it specify vid and pid. https://github.com/PaulStoffregen/teensy_loader_cli/blob/master/teensy_loader_cli.c#L669 Teensy have same vid and pid. I think that new function option need to specify usb port.

[hmaarrfk]

You can try

https://github.com/PaulStoffregen/teensy_loader_cli/pull/57

Only works on linux.

I did the bad thing on releasing the feature on conda forge as well

[takurx]

Thank you. That's helpful for me!! I will try it.

[FiratSusan]

Greetings, I was playing around with your changes so I can use this serial-number functionality with PlatformIO to flash my two teensy via USB only and I noticed a strange thing.

This is the output from usb-devices for my teensy:

T:  Bus=03 Lev=02 Prnt=05 Port=00 Cnt=01 Dev#=  7 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=16c0 ProdID=0486 Rev=02.79
S:  Manufacturer=Teensyduino
S:  Product=Teensyduino RawHID
S:  SerialNumber=7365140
C:  #Ifs= 2 Cfg#= 1 Atr=c0 MxPwr=100mA
I:  If#= 0 Alt= 0 #EPs= 2 Cls=03(HID  ) Sub=00 Prot=00 Driver=(none)
I:  If#= 1 Alt= 0 #EPs= 2 Cls=03(HID  ) Sub=00 Prot=00 Driver=usbhid

As you see, my serial-number is 7365140.

I had issues flashing my teensy and noticed that the serial-number which gets parsed out of your code is not matching to my serial-number.

I added some prints to your code:

...
if (dev->descriptor.iSerialNumber) {
    // langid 0x0409 is English US
    r = usb_get_string(h, dev->descriptor.iSerialNumber, 0x0409, buf, 128);
    if (r < 0) {
        usb_close(h);
        continue;
    }

    // Seemsl like 16 bit wide chars are being sent
    for (i=0; i < r/2; i++){
        buf[i] = buf[i * 2];
    }
    printf("%s\n", buf);
    // The first char seems to be of value 16
    // meaning DATA LINK ESCAPE. Who knows what that means???
    read_serial_number = &buf[1];
    printf("%s\n", read_serial_number);
} else {
...

Here is the output of PlatformIO using your changes + outputs from me:

...
Configuring upload protocol...
AVAILABLE: custom, jlink, teensy-gui
CURRENT: upload_protocol = custom
Uploading .pio/build/teensy_rear/firmware.hex
Teensy Loader, Command Line, Version 2.2
Read ".pio/build/teensy_rear/firmware.hex": 16180 bytes, 0.8% usage
73651405
73651405
Sending reboot command to 7365140
...

Any idea why this happens? Either usb-devices is not displaying the serial numbers correctly or the conversion from 16bit values to 8bit is not working right.

[hmaarrfk]

do you have two teensies connected?

[FiratSusan]

In the run shown above, no.

[hmaarrfk]

are you using a standard intel based computer? I've been using this for quite some time and it seems to be "working" but maybe there is a bug....