Wooden Pi Handheld

Details

Handheld with case design inspired by the old Tiger games.

Display -Generic 3.5in HDMI TFT LCD

Sound - HDMI out to 2.5W amplifier to bone conductor transducer

Power - 3.7v 8000mah battery connected to USB power bank board to ATXRaspi for safe shutdown. Micro USB on back for charging.

Case and buttons - bamboo, oak, acrylic and aluminum designed in OnShape and cut on homemade CNC router.

Input - 6mm tact switches and 8x8x5MM silent switches, CNC cut and drilled PCB.

CPU - Pi 3B+ -removed USB and LAN connectors in order to make board as thin as possible. Re-routed one USB port to micro USB connector on back of case.

Software - RetroPie and Rretrogame for input

Files

IMG_20180910_114515.jpg

JPEG Image - 192.56 kB - 01/26/2019 at 01:28

Preview

IMG_20181013_173705.jpg

JPEG Image - 278.25 kB - 01/26/2019 at 01:28

Preview

IMG_20180924_203020.jpg

JPEG Image - 299.76 kB - 01/26/2019 at 01:28

Preview

IMG_20181013_150245.jpg

JPEG Image - 261.04 kB - 01/26/2019 at 01:28

Preview

IMG_20181104_115427.jpg

JPEG Image - 356.22 kB - 01/26/2019 at 01:28

Preview

Components

1 × Raspberry Pi 3B+

1 × 3.5 in HDMI TFT LCD

1 × 3/4 Red Oak board

1 × Bone Conduction transducer

1 × ATXRaspi

Project Logs

Collapse

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.

View all 3 project logs

Discussions

mambstardust wrote 02/24/2019 at 05:24

Hi mate! I am on the same kind of project, but using an orange pi pc 1gb ram. Well, it's my first time in this world, so I had some issues with my lack of knowledge of the electronics stuff, as long as it's a way I found to learn while doing a nice stuff, but most of it is already solved. Now, the only problem I'm facing is with the commands PCB. I didn't want to make any adaptation with others joystick PCBs, I wanted to make it my own, but I need a layout, and as long as I don't have the knowledge to project it, if you could tell me where I could find a layout for the commands and d pads, or share yours, as long as I also have 6 buttons command. If I'm not asking too much, I'd be very thankful. Your project is awesome, congratulations, mate! Thanks a lot for sharing, it was a huge inspiration and light for me hahahaha

Are you sure? yes | no

Josh Baumgardner wrote 01/30/2019 at 19:58

Thank You! Roughing pass was with a .125" 2 flute ball nose mill .67 mm per pass 2 mm layer height. Finishing pass was .0625" 2 flute ball .09 mm per pass. The buttons were roughed the same and finished with a .5 mm cone at .1 mm per pass. It took a while to finish routing, but very little sanding was needed on the case, just a little cleanup on the button holes.

The controls are a little close the the bottom, but it is not uncomfortable to hold for long periods of time, the 30 mm thickness and indentations in the back of the case help with that.

Are you sure? yes | no

Mike Szczys wrote 01/30/2019 at 19:36

Also, some tips: You can embed your images in project logs or project description and they will automatically get added to the gallery (instead of uploading them in the files section which is a place great for posting design files, etc.). I love the picture of your workshop!

Are you sure? yes | no

Mike Szczys wrote 01/30/2019 at 19:08

The bamboo parts on that case look beautiful. I'd love to hear more about the milling process for these. Did they require a lot of sanding and finishing?

Also, the controls are very close to the two bottom corners. I wonder if it is comfortable to hold for a long time while playing? (For instance, Game Boy had more area below the d-pad and buttons for you palms and fingers to grip).

Are you sure? yes | no

Wooden Pi Handheld

Description

Details