BDN9 Build Log


The BDN9 is a macro pad produced by Keebio. It supports four layouts: 3x3 grid, single rotary encoder in the top left or top right, or dual rotary encoders.

I followed the guide at

hope i dont duck this up
bottom of pcb
top of pcb
ZugGear T1 linear switches and rotary encoder knob
switch plate and base

Doing the building part

Started by soldering all the resistors.  

first resistor to be soldered
resistors completed

next for the MOSFET  and the reset button

reset switch

After those, I soldered the pro micro headers into place. The holes are slightly... staggered...? I thought the board was defective but that's just the design. I think it's supposed to allow for the pro micro to be pressure fitted. After the headers were in, I soldered the rotary encoder in place.

rotary encoder and headers

Pressure fitting the switches into the top plate

top of switch plate
bottom of switch plate

Everything fit well and looked nice. Let's bake this cake.

all melted together

I was following the keebio instructions and part of them was to place some type of nonconductive barrier between the PCB and the pro micro. While building this I almost didn't do this because it looked liked it would be fine. But I followed the instructions anyways.

yellow electrical tape covering the bits under where the pro micro sits

I plopped the pro micro in and melted it. It was a super tight fit. I had to clip the headers with flush cutters to get the base to sit properly. I'm glad I followed the instructions instead of improvising.

v tight. 


The main of attractions of this board were the rotary encoders and that there was VIA compatible firmware available. I downloaded the v1 firmware from the VIA website and used QMK Toolbox to flash the pro micro. Did the obligatory clicks and clacks of success and made sure all the switches were passing input.

The stock firmware had a surprisng setting for the right rotary encoder. Twisting left or right triggered the page up/down key codes. Pressing down toggled the mute state. I cloned the QMK firmware repo and found the folder for the VIA firmware for the board. I copied and renamed it. I modified the keymap.c to make twisting the knob raise or lower the volume. Then I complied the firmware with the changes and reflashed the board.


capless switches
ready to go

Side Note

Since the rotary encoder doesn't lock into the switch plate, it dipped a little when I depressed it. I used a hot glue gun and placed a line against the switch plate and the PCB. It's working OK and fixed the issue, but hot glue isn't insulated so... shrug?

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