Wednesday, June 21, 2017

Alps 48 RGB

48 Key Per Key RGB - Rainbow Cat Vomit 1.2 PCB

  • 4x12 matrix
  • Per key RGB reactive lighting
  • Powered by two Pro Micros
  • TMK on first Pro Micro, same firmware as the Gnap!
  • Arduino sketch running on second Pro Micro
  • 48 WS2812B LEDs
  • Matias click switches with clear body
  • 1.2mm PCB
  • 1.2mm top plate
  • 1.6mm bottom plate
  • 19.05mm switch spacing. Not compatible with the Planck
  • M2 11mm spacers
  • 0805 0.1 uf capacitors
Full RGB 48 key Alps ortholinear keyboard. This uses the same firmware as the Gnap! which uses the serial port to communicate with the second Pro Micro which is controlling the LEDs. Instead of a single color LED matrix on the Gnap!, the second controller is connected to a string of WS2812B LEDs.

The WS2812B LEDs fit snugly in the cutouts. Tiny solder bridges connect the LEDs to the PCB. 1.2mm PCB was used to make the bridging easier. With 1.6mm PCB the LED sits low in the cutout and the solder bridge was difficult to form. It works just like the 30% MX RGB board, but with Alps there is no center switch stem and the LED could be placed closer to the center of the switch.

The only problem in assembly is the sockets for the Pro Micros. The Alps switch is wider than an MX switch. The pins from the socket touch the edges of the switch. The pins need to be trimmed as short as possible and soldered as flush to the surface as possible. I also ground the edges of the switch down a little so that they would sit flat against the PCB over the pins.

Running the LEDs at 1/4 power it draws about 400mA in a full rainbow display. The Adafruit Neopixel library lets you set the maximum brightness. Potentially I could plug in both Pro Micro's at the same time to provide more double the current, though it is already quite bright at 1/4 power.

Currently deciding on revising the PCB with the Pro Micros rotated like on the Gnap!. This would remove the problem with the socket pins. Would have to either plug in from the side, or run a pigtail to a USB connector on the back like on the Gnap!.
One of the color patterns programmed in the the Pro Micro running an Arduino sketch. You can see more of them in the video at the bottom of the post.

The top PCB plate was originally green but I sanded it down to the bare FR4 material.

The schematic showing the switch matrix with the WS2812B LEDs integrated.

Front and back of the PCB. On the top you can see how the pins of the socket overlap the white outline of the switches.

Side view showing the two Pro Micros. The one on the left os running TMK, the one on the right is running the Arduino sketch.

11mm brass spacers.

The Pro Micro running TMK. You can see how the pins from the socket would interfere with the switch if they were not trimmed.

The Pro Micro running the RGB Arduino sketch.

Random LED output. There is also an interactive mode that lights up the switches as they are pressed and then fade. There are many WS2812B effects libraries for the Arduino.

Monday, June 19, 2017

Tomato 1.3 30% RGB

Tomato 1.3 PCB

Latest version of the Tomato PCB, this time with red solder mask. Minor fixes. Otherwise identical to the previous version. This one has a steel top and bottom plate from Lasergist. The switches are Cherry MX Speed Silver RGB. They have translucent bottoms and clear tops.

Friday, June 16, 2017

Cherry ML

Cherry ML "Planck"

Custom keyboard with Cherry ML switches. The switches and keycaps were harvested from two different keyboards. The orthogonal PLUM keyboard and a Cherry G84-5500LPMEU-2.

The PLUM keyboard is a long discontinued model. You can still find them in unused condition on eBay. The Cherry is an obsolete PS2 model that can be found for under $20 on Amazon.

The is powered by a Pro Micro. The matrix is identical to a GNAP! without the LED matrix.

The switch spacing is 19.05mm. This is what most keyboards use and is what the PLUM keyboard was designed as.

The PLUM has all 1u keys and has most of the keys you would want, even some blanks.

The Cherry keyboard has smaller keys. The switch spacing was 18mm. A few keys were even narrower (ESC, Del).

The PLUM keycaps are also taller. In the picture the PLUM keycap is resting on the prongs that stick out below the keycap.

The PLUM keycaps are ABS and Laser marked. The prongs are smooth and are held in the switch by friction alone.

The Cherry keycaps are also ABS and laser marked with a different technology. The legends look like laser foaming. The prongs have small nubs that click the keycap into place in the switch. These feel much more secure than the PLUM ones.

The PLUM keycaps are centered on the stem of the switch. The board was designed for these so the spacing is even around the edges of the keyboard.

The Cherry keycaps are centered on the switch itself. So the keycaps sit closer to the bottom edge of the keyboard. The keycaps are also closer to the board and were touching the diodes, so they were installed on the bottom of the board for this one.

A Planck is 28mm thick with DSA keycaps. The ML is 19mm thick with PLUM keycaps, 18.75mm with Cherry keycaps.

Currently using 6mm spacers, the next version will use 5 or 4mm spacers.

Tuesday, June 13, 2017

Double Gherkin

60% Gherkin

Two Gherkin PCB's mounted to a double base plate. The two 5x6 matrices combined into a single 10x6 matrix.

Both PCB's are connected to a single Pro Micro. One switch from each column is bridged to the corresponding switch on the other PCB. The header is used to bridged the connections for the unused pins, VCC and ground to the other PCB. Where the other Pro Micro would have been the unused pins are jumpered to the correct rows.

The backlight also works. A single MOSFET is used to control all the LEDs on both PCBs.

Details of the pinout and modified firmware can be found on Github.

Two Gherkin PCB's spaced correctly.

The baseplate.

The connections between the two PCB's.

The power and row pins.

The column pins. Also the connection from the other PCB to the single MOSFET.

Wires are visible from above.

6mm spacers.

The single Pro Micro.

LEDs on.

XDA blank key caps.