Unfortunately, I ran into some hiccups with the v4 PCB, and since it mostly involves small SMD components, debugging it proved difficult. Instead, I pivoted to testing some basic shift register logic with a more well document shift register, the 74HC595, with the Arduino Nano. Below is a video of 3x2 braille cell-style array of LEDs flashing through the braille alphabet while being controlled by the shift register.

The Arduino code can be found in braille_flash.ino in the GitHub.

Next Steps:

I will try to control an H-bridge IC with the shift register and hopefully be able to control current flow through the coils. Once that works, I will begin designing the v5 PCB implementing these new shift register/h-bridge ICs.

Update 3/11/2025:

Shift Register and H-Bridge ICs arrived, and PCBs arrived. Soldered SMD components on using microscope and fine soldering tip.

Next Steps:

Write Arduino code to control shift register and send input signals to H-Bridge ICs.

Update 12/17/2024:

Researched different ICs for controlling a full 6-dot braille cell.

TLC6C5912-Q1 12-bit shift register, to control all 12 outputs associated with the full cell. Two outputs are required for each dot to drive current in both directions.

DRV8212DRLR H-bridge motor driver IC, to take digital signal from shift register and enable current flow in a specified direction.

Completed PCB v4 design:

3D render:

KiCad design:

Completed PCB v4 Schematic:

(coils not shown)

Update 11/13/2024:

PCB Arrival

PCBs arrived from JLCPCB (pictured below)

Completion of First Prototype

Soldered pin headers, bolted 3D-printed assembly to PCB

Successful Testing

See video

Update 11/04/2024

First prototype PCB design consists of two coil setups, one of which is a single layer, the other being a two layer version, connected in series. Each coil is 6mm in diameter with a 0.15mm trace width/clearance, and approximately 9 turns per layer.

PCB design:

CAD model:

M2 bolts will be used to align and fasten the outer 'chamber' part over the center of the coil.

The two parts were printed on the Creality Halot Lite SLA 3D-printer using clear ABS-like resin.

Printed parts (microSD for scale):