Project Logs

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• Battery Life

  Josh Baumgardner • 01/30/2019 at 15:45 • 0 comments

  Battery Life - about 6 hours run time, takes about that long to charge back up.

• Design modifications

  Josh Baumgardner • 01/26/2019 at 01:17 • 0 comments

  Second prototype made several design changes -  Switched from Pi Zero W to Pi 3B+, Required some serious slimming down of the PI.  Used better battery and charge circuit,  Routed the keyboard PCB in one piece, modified button design to include routed letters and orientation tabs and 3D printed cage to keep buttons aligned.  Slightly changed button positions and added indentations in the back of the case to improve ergonomics.   

  Discovered an issue with the power circuit.  The USB power bank board shuts itself down when no power is being drawn, it has a button that will wake it up, so I wired a second switch beside the ATXraspi power switch that is activated by the button at the top of the case, this requires two presses to turn the unit on,  first press turns on the power, second press turns on the ATXraspi which powers the Raspberry Pi.

  The problem is that while the USB power bank board will consistently come on, sometimes the ATXRaspi will not..  I discovered that by shorting the power input to the ATXRaspi while the USB power bank was off that I was able to make everything start working normally again.   Since this problem is intermittent, I added a reset switch to the bottom of the case via a small pin sized hole with a switch that shorts the ATXraspi input when the issue occurs.

• Lessons learned from first prototype

  Josh Baumgardner • 09/19/2018 at 18:13 • 0 comments

  Realized too late that the design for the "keyboard" required the Pi Zero to be upside down, also putting the power breakout board on top of the stack was a bad move - made accessing the SD card difficult. 

  Redesigning the board to be in one piece and have the Pi oriented properly, also breaking out the power pins on the keyboard to eliminate having to use a separate board for power connections.   

  Also need to tweak the screen size on the case model to better fit the viewable area. may also modify the back case to accommodate a regular sized USB port so that peripherals can be connected more easily. This would reduce confusion  on which of the two ports is the charge port and prevent accidentally powering up the Pi through the data port.
  

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