Debug and sketch upload over serial# UART?

[b2020]

I am facing a situation where I need the on-board micro-USB of the Teensy for other purposes, but don't want to lose the ability to connect to PC, including for dev/debug over COM.

Is there an example of anybody using any of the non-USB serial
https://www.pjrc.com/teensy/td_uart.html

for debug including sketch upload?
Say, with an off-the-shelf USB-to-serial adapter: USB attached to the PC, serial attached to Teensy?

Is it just a matter of making the Teensy Serial# show up as COM on the PC, or are there other constraints e.g. on sketch upload?

[PaulStoffregen]

Teensy uploading is done using USB HID protocol. USB serial isn't used at all for uploading.

Teensy only acts as a USB serial device while running your program, and only if Tools > USB Type is set to one of the options with Serial.

[b2020]

E.g. the Teensy version of this

https://arduino.stackexchange.com/qu...ort-rx-instead

[b2020]

Teensy uploading is done using USB HID protocol. USB serial isn't used at all for uploading.

So that means whenever I want to change the sketch, I have to physically unplug the target host and plug the dev PC into the on-board micro-USB?
I could run the uploader on the target, as part of a test app.

Start here?
https://github.com/PaulStoffregen/teensy_loader_cli

Teensy only acts as a USB serial device while running your program, and only if Tools > USB Type is set to one of the options with Serial.

I found this
https://forum.pjrc.com/threads/26024...a-new-USB-type
so I could try to tailor a custom type to whatever the target hosts support/permit. As you mentioned in the original threat - thanks!

[b2020]

From

"Teensy can only be programmed through the USB Micro connector - or {for T_3.2} the equivalent USB pins connected on the underside. There is no mapping through UART Serial or other way to program a Teensy through the bootloader chip."
https://forum.pjrc.com/threads/57963...Serial-adapter

[b2020]

For debug printf to PC over a non-USB Serial, I'll try something like this

https://www.amazon.com/CP2102-Module...dp/B009T2ZR6W/

from https://openwrt.org/docs/techref/har....serial.cables
If somebody has used something like this with a Teensy 3.x or 4.x and has a recommendation, links appreciated.

[XFer]

I use the CP2104, more compatible with Windows 10:
https://www.amazon.com/WINGONEER-CP2...9657667&sr=8-9

and yes, I often use Hardware Serial1 as a debug port to the PC.

I have my own Serial Terminal, but any will do, for example the notorious PUTTY.

[defragster]

Yes if set to 3.3V and connected to Teensy UART that should work. Or it can be done with another Teensy with a simple ECHO program.

@XFer linked item seems better as noted.

TyCommander in use here works with Multiple Teensy's and should connect to the CP2104 as terminal too.

[b2020]

Thanks guys!