Tuesday, October 17, 2017

Green Arduino Micro

Green Arduino Micro Clone

The Arduino Micro has 24 usable i/o pins, as many as on a Teensy 2.0. Same ATmega32u4.

Not a Pro Micro, a Micro. There is an official Arduino Micro. This is a redesigned clone I found on Aliexpress. It shares the same pinout, but has all of it's components on the top of the PCB. The bottom is completely flat. It also comes without the ISCP header installed and uses a smaller reset switch. Very low profile compared to the official Arduino Micro.

You can find these on Aliexpress by searching for CNT-013. They are also very cheap for what they are. Currently $3.50 each plus shipping, that's the same price as the smaller Pro Micro clones. Most other Arduino Micro clones are selling for twice that price.

Like the green Pro Micro it has a simplified power supply. Otherwise it should work just like a genuine Arduino Micro.


Low profile with a smaller reset switch than what is used on a genuine Arduino Micro.

The bottom has no components. The genuine Arduino Micro has the power supply components on the bottom.

Monday, October 16, 2017

GOTW #4

Gherkin Of The Week #4

Black top 30% Edward

Another variation on the 30% Edward. The top plate was sanded down and dyed black. The bottom is an experimental perforated PCB.

 Translucent black keycaps from Flashquark.

 M2 spacers and screws.

Perforated bottom plate.

Friday, October 13, 2017

PI Zero TMK ISP

Using a Raspberry Pi to compile TMK and as an ISP programmer

I have been using Raspberry Pi's for various things since they have been generally available. They make great general purpose embedded computers. Since they are running Linux they can be made to do just about anything.

The default Raspbian distribution has everything necessary to compile TMK. There are many guides to setting up Raspbian. Once you have it up and running you need only run the following command to install all the additional software for compiling.

sudo apt install gcc-avr avr-libc dfu-programmer git

That installs the gcc avr compiler and the avr libraries for the ATmega series of chips. dfu-programmer is for programming chips over USB with the DFU protocol. git is for cloning the TMK code from github.

git clone https://github.com/di0ib/tmk_keyboard.git

This will clone my fork of TMK.

This video shows the whole process. I did it on a Raspberry Pi Zero, it will work the same on a Raspberry Pi 3 or 2, or the original Pi.


I also tested this on a Raspberry Pi 3. It compiles in half the time as the Zero. 28 seconds vs 59 seconds to compile the default Gherkin firmware.

Pi GPIO ISP

I did not install avrdude from the Raspbian repository. Instead I installed it manually using the instructions on Adafruit. They have detailed instructions on how to install a custom version of avrdude that supports the GPIO outputs of the Raspberry Pi.

I used the same pogo pin contraption I use with my other programmer.

 Pogo pins to connect to a Pro Micro.

 Connected to the Raspberry Pi GPIO header with jumper wires.

Closeup of the connections on the GPIO header.

I tested this on a Raspberry Pi Zero with USB WiFi. I controlled it remotely over the network through a SSH session.

The Raspberry Pi Zero (W) does not come with a header installed. The normal sized Raspberry Pi 2 and 3 do have the header installed.

What can you do with an ISP programmer?

You can program the Atmel chip directly without using the bootloader code. You can also replace the existing bootloader with a different one. Or, if you want all the space available, you can overwrite the bootloader and use all the flash space for your code, and not have a bootloader.

Wednesday, October 11, 2017

Red 6lit

6lit with RED PCBs

Ordered some colored (color other than green) PCB's from JLCPCB.These are identical to the green 6lit, only the color is different.

Bought a white right angle TRRS cable from Sparkfun.

Left over G20 Semiotic keycaps.

Red looks good and the branding on the PCB does not show through. With green soldermask the red branding on the bare PCB material sometimes shows through.

6mm M2 spacers and screws.

Monday, October 9, 2017

GOTW #3

Gherkin Of The Week #3

Aluminum bottom Gherkin

Took a piece of 1/16th thick aluminum and punched holes in it that match the switch positions. I used one of those cheap metal punches from Amazon. I used a spare PCB as a template to position the holes. The holes for the M2 screws I drilled with my Vanda-Lay drill press.

The black PCB is one of the ones I made at JLCPCB. It has no silkscreen layer and is all black on both sides. I also installed the diodes and resistors on the bottom of the PCB.

 Gateron clear switches with green 2x3x4 LEDs installed inside them.

 M2 spacers and screws.

 Aluminum plate with punched holes. The plate was a little short.

Closeup of the PCB with no silkscreen markings.

Wednesday, October 4, 2017

DeathStar II

DeathStar with Black PCB

Got these made at JLCPCB.com with black soldermask. The previous version was with plain green soldermask. The PCB's are the same, just different color.

I used self flashing LEDs on this one. The outer ring of LEDs are the slow flashing type and the center are the fast flashing type. See the video below.

Links to PCB and firmware in original post.

 Gateron Clear switches. The 2x3x4mm LEDs are inside the switches.

 The LED color pattern starts off in sync, but then starts to drift and look random.

Smoke grey translucent keys from Flashquark.

Tuesday, October 3, 2017

GOTW #2

Gherkin Of The Week #2

Alternate 30% Edward

One of the many iterations of the 30% Edward. This one has the same handles but they are attached to the bottom instead of the top plate. The bottom is 1/16" aluminum plate.

 SA keycaps from grab bags.

 The bottom plate I got off of eBay. Drilled the holes with a Dremel in my Vanda-lay drill press.

Regular PCB top plate and M2 spacers and screws.

Row 2, 3, 4 SA sculpted keycaps. The switches are Kailh Bronze clicky.

Wednesday, September 27, 2017

Green Pro Micro's on eBay

Green vs Blue Pro Micro

They are not completely compatible with the old blue colored ones. Some sellers even list both, giving you a "color" choice, but they are two different designs. Details in this post.

You do not want these green ones if you are building a Let's Split style keyboard that uses two Pro Micro's. This includes the Foobar, and the other split keyboards I have made.

The original Sparkfun Pro Micro is Red. Color may not be a reliable way of identifying these. You should compare the physical differences in the components near the USB connector.


Monday, September 25, 2017

GOTW #1

Gherkin Of The Week #1

I usually only post when I have something new or different to share, so I have many Gherkins that I have not posted.

I am going to start posting some of these Gherkins weekly. Some are nothing new, just a different combination of parts/switches.

Alps Gherkin with Matias Linear switches, RGB underglow and red plates.


 Very festive green PCB top and Red PCB bottom.

 M2 brass spacers.

 10 WS2812b RGB LEDs. The Alps Gherkin PCB has spots to solder the strip directly to the board.

Red PCB bottom.

Thursday, September 21, 2017

Kon Tiki

Second generation Plover Gherkin mod

Similar to the Outrigger, this time a Gherkin PCB combined with two 2 switch macropad PCBs. Using the two macropad PCBs allow the bottom row to be split.

Construction and wiring are the same as the Outrigger. It runs the same firmware. The gerber files for the plate are on github.

G20 keycaps. They seem to be the easiest to get keycaps that work reasonably well with a steno keyboard.

The wiring is the same as the Outrigger. The grounds on the two macropads are connected together, then connected to F6. The switches are connected to existing columns.

 Gateron 35g clear linear switches.

Bottom plate. The top plate has the knockouts removed to fit the switches in.

Side view of the Pro Micro. M2 spacers and screws hold the two plates together.