[Solved] External usb port to charge and program teensy

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inimidi

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Hello world,

I am currently making a pcb for a lipo-charger with load sharing for a research prototype[1].
The micro-usb of the charging schematic will be made flush with the outer wall of the casing for easy-peasy usb charging for our target group.

However, I only have space for a single micro usb socket. Next to it will be a breakout for a push-push sd card reader for the audio shield. So I was thinking on connecting the lipo-usb port to the teensy in such a way that it doubles as a way to program the teensy. This would allow us to upload software updates without needing to take the device apart.

I was looking at the schematic and the pins of the teensy’s micro usb port don’t seem to connect to any of its board’s pins[2]. The schematic however shows that some traces that are connected to the micro-usb port have dead ends (tiny black squares). Do these indicate pads on the board I could access?

Little curious side question: why are DAT1 and DAT2 of the micro SD card not used on the audio board[3]?

1 : Lipo charger + load sharing:
http://blog.zakkemble.co.uk/a-lithium-battery-charger-with-load-sharing/

2 : Complete Teensy 3.2 schematic:
https://www.pjrc.com/teensy/schematic.html

3 : Audio board schematic:
https://www.pjrc.com/store/teensy3_audio.html
 
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I imagine there are a couple of ways to have a combined micro SD card and micro USB opening.

  • The first way is to put a micro USB port above the micro SD card slot on the audio shield. If you look on the bottom of the 3.2, there are the D+/D- pads that you would connect to the USB port, along with VUSB and ground. If you want to make a switch to turn the Teensy on/off, you could cut the trace between VUSB and VIN, and then connect VIN.
  • If you don't want to solder to the D+/D- pads, you could always make a custom USB cable that plugs into the Teensy's USB cable, and then goes to the charger interface.
  • Run a micro SD extender cable from the audio shield to a SD slot above/below the Teensy USB slot for example: (https://www.tindie.com/products/TEMProducts/micro-sd-extension-cord/?pt=ac_prod_search)
  • Add a new micro SD card reader to the Teensy and don't use the one on the audio shield.
  • Add 2 openings to your case, one for USB, and one for SD card.
 
MichaelMeissner said:
I imagine there are a couple of ways to have a combined micro SD card and micro USB opening.

  • The first way is to put a micro USB port above the micro SD card slot on the audio shield. If you look on the bottom of the 3.2, there are the D+/D- pads that you would connect to the USB port, along with VUSB and ground. If you want to make a switch to turn the Teensy on/off, you could cut the trace between VUSB and VIN, and then connect VIN.
  • If you don't want to solder to the D+/D- pads, you could always make a custom USB cable that plugs into the Teensy's USB cable, and then goes to the charger interface.
  • Run a micro SD extender cable from the audio shield to a SD slot above/below the Teensy USB slot for example: (https://www.tindie.com/products/TEMProducts/micro-sd-extension-cord/?pt=ac_prod_search)
  • Add a new micro SD card reader to the Teensy and don't use the one on the audio shield.
  • Add 2 openings to your case, one for USB, and one for SD card.
Click to expand...

Soldered the micro usb port extension using the smd pads at the bottom of the PCB, turned out great :D

How do I change the tittle of this thread so it includes: [SOLVED] ?
 
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