ATREUS


Build Log: Atreus Deck Mark I

2018-06-15

Decided to abandon plans for portrait-oriented all-in-one design since the portrait-orientation for the LCD on a Pi actually just leaves most of the screen unusable.

initial case

initial case

Designed and fabricated screen housing; installed screen into it. Still not connected to the keyboard or Pi at all.

2018-06-17

Created mounting bracket for Pi and LCD adapter board; one central rectangle with arms reaching out to the main corner screws.

first bracket

first bracket

This design did not leave clearance for the Pi's USB ports, and the arms were thin and flimsy. The M2.5 screws I have are long enough to secure the LCD adapter board, but they don't reach to the Pi itself, so only the header pins are holding the Pi in place.

2018-06-18

Constructed second revision of the mounting bracket with more clearance for the Pi and less flimsy arms.

second bracket

second bracket

Still had a few mm of a clearance problem with the Pi's ethernet port, but was able to make it work. Noticed that the inner M2.5 screw holes are slightly too close together, but the Pi and adapter can still be mounted.

2018-06-20

Used two pieces of bent wire to attach the screen to the keyboard.

wire attachment

wire attachment

This turned out to be stronger than I expected; I was worried it wouldn't really hold up when moved around and jostled. Apart from requiring an AC adapter to operate, I'm pretty satisfied with this design. I'm able to take it with me around the house. My first pass of the wire attachment is difficult to remove once installed tho, and I'd prefer it if it were easy to snap on and off.

2018-06-21

Disassembled the screen casing to remove the screen protector film. Upon reassembly, the screen went dead, and the FPC connector piece on the adapter board snapped off. The display can be brought back to life by applying pressure to a specific point on the ribbon, but it raises questions about the suitability of LVDS for this project; if it can't last more than a day, it may be better to switch to HDMI despite the higher power consumption and complexity.

Cut a replacement screen case in Oak ply with the M2.5 screw holes at the correct distance. Using wood revealed that the bracket design was backwards, which isn't noticeable in acrylic.

Discovered that braiding a USB cable is a terrible idea and will make it stop working.

2018-06-27

Elecrow 5-inch HDMI Pi screen arrived. Designed a new back plate to accommodate the new screen which holds the Pi much more tightly. New setup works fine, but without a battery it's not mobile. This back plate doesn't have any mounts for the battery or charger. The new screen design necessitated a wire mount of a slightly different shape.

2018-06-30

Lithium ion polymer battery and charging circuit arrived. Went to a local store and picked up a nylon strap. Replacing the thicker spacer with a thin spacer on one of my keyboards, I was able to slip the nylon strap between the spacer and the bottom plate after punching a few holes in it.

wooden pi deck with elecrow screen

wooden pi deck with elecrow screen

Having the strap and being mobile made the lack of a battery even more noticeable, so I cut a new back plate to allow the battery to be attached. Put a couple 2.5M screw holes (thanks Adafruit) near the screen's switch, added a cut out to expose the 5V in and GND pins on the display PCB, and added a couple slots to loop a rubber band thru a bit lower down.

The rubber band seems to work holding the battery in place. But having the battery adapter board near the screen switch was a mistake; it's an awkward position especially when using the device while it's charging. I'm not sure what to do about the 2.5M screws for the battery board as adding the nuts I have might cause a short. I need to find a shorter USB cable for the keyboard. Having to disconnect the JST cord of the battery and reconnect to power on is kind of lame too,

But ... it works!

back shot of Pi with Electrow screen

back shot of Pi with Electrow screen

To be continued...