4.1 with battery, single USB to program and charge. Device not recognized.

Robot

Member
I have my Teensy 4.1 powered by an adafruit powerboost 500 with a lipo. I want to be able to charge the battery and reprogram the teensy over the same USB port.

What I've done:

Code:
USB data ---------------> Teensy USB
USB power -> Powerboost ----^

Charging and powering the Teensy works fine, but plugging everything into a PC gives me "Device not recognized". Using the Teensy directly with the PC works, I've checked continuity on every line, and everything I've looked at suggests this should work... but it doesn't.

Anyone know what I'm doing wrong? or how to fix it?
Thanks.
 
Looking at the schematic on the Powerboost, the micro-USB connector on the Powerboost does not connect the D+/D- pins, so there is no way to use that port directly.

What you can do is use the Teensy's micro-USB to provide the power. You would need to cut the jumper underneath the Teensy that connect VUSB (power from USB) and VIN (power the Teensy). Here are some old posts about it:

Then you connect the following pins:
  • Teensy VUSB to Powerboost USB;
  • Teensy Ground to Powerboost GND; (and)
  • Teensy VIN to Powerboost 5v.
 
I am not using the micro USB connector on the powerboost. I have a 3rd USB connector that is not attached to any boards. From that I connect the data lines to the Teensy, and the power lines to the boost.

Also, as far as I understand, no connection to the data lines wouldn't result in a 'Device not recognized' error, it would just send power and the PC would do nothing.
 
PowerDataWireing.png
Hope this helps. Obviously there are other things connected to the Teensy as well. Also I tested the ground, it is continuous between both boards and the USB connector.
 
I have my Teensy 4.1 powered by an adafruit powerboost 500 with a lipo. I want to be able to charge the battery and reprogram the teensy over the same USB port.

What I've done:

Code:
USB data ---------------> Teensy USB
USB power -> Powerboost ----^

Charging and powering the Teensy works fine, but plugging everything into a PC gives me "Device not recognized". Using the Teensy directly with the PC works, I've checked continuity on every line, and everything I've looked at suggests this should work... but it doesn't.

Anyone know what I'm doing wrong? or how to fix it?
Thanks.

@Robot:

If I understand your request correctly, I did that exact same thing for my TeensyMIDIPolySynth project using the Adafruit PowerBoost 1000 (2465) & the Adafruit Panel Mount Extension USB Cable Micro-B Male to Micro-B Female (3258). I opened up the middle of the cable & split the 5VDC & GND wires, leaving the D+ & D- signals intact. The power wires from the panel-mount socket were connected to the input of the PowerBoost, & the power wires to the Micro-B Male connector were connected to the output of the PowerBoost. The Micro-B Male was plugged into the T4.1 (no cutting of the power trace). Cabling from the PC to the panel-mount socket allowed programming/serial monitoring of the T4.1 (& low-current battery recharging, although that was just a by-product of the connectivity). Cabling from an external USB supply to the panel-mount socket allowed full-current battery recharging and/or powered operation. With nothing connected to the USB, portable operation on battery power was accomplished.

I believe that, with your intent & hardware (if I understand everything correctly), you should definitely be able to do the same thing.

Mark J Culross
KD5RXT
 
Cool, yeah, that's very much like what I'm doing... but it doesn't work. I'm not sure what to do next to troubleshoot the "Device not recognized" error windows is giving me.
 
I'm doing something like this with a Teensy 3.2.

In your drawing you have the PowerBoost 5v output going to the T4.1, so it (may) only gets recognised as USB device when it is powered on. Maybe the T41 is barely getting enough phantom power thru the D+/D- inputs so it does not respond properly. The PowerBoost has an output that is either V-battery or 5v so one could hibernate the teensy to conserve power, I don't do that.

In my use, I have the Vin trace jumper cut on the T32 and feed V-USB to the PowerBoost. I feed the 5v PowerBoost output voltage to the T32 Vin (corner pad). This allows me to charge the battery with the system off. I control the PowerBoost with a nand gate wired to react to short touch on & long touch off. I also allow the T32 to force shutdown when the battery voltage gets too low. I do not use the USB connector on the PowerBoost either.
 
The T_4.1 uses 480 Mbps USB. As presented (if I read right) by @KD5RXT-mark there is less disturbance and rerouting of the USB 'D' signal lines where it seems they are uninterrupted from the original cable. Not soldered twice and routed with the makeup wires or shielded cable? Also better GND integrity with the Teensy on the cable to the PC. Feeding the GND as indicated only across the AdaF board might induce noise and a lesser connection?
 
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