Chainlink Driver v1.1 Electronics User Guide


If you’re just getting started and want to learn more about the Chainlink Driver, jump to the bottom of this document which includes some more background and general info.

Please let me know if you have any questions or suggestions on how to improve these instructions - either leave a comment inline below (need to be logged into Dropbox to do so, I believe) or else email me directly at scottbez1 at

Building a split-flap display? I would love to hear from you and see photos/videos of your project in progress or completed! This project has been a hobby of mine for a few years and the coolest part by far is hearing from other people making their own and seeing them in action. Feel free to shoot me an email at scottbez1 at 🙂 or, join the Discord server, to share and discuss with the wider split-flap community!

1. Gather the parts

  • Chainlink Driver PCB assembly (see appendix for ordering info)
  • Connectors (all included with the Chainlink Driver boards I sell on Etsy)
  • 6x JST XH 5-pin
  • 6x 3-pin male headers
  • 2x 8-pin 2-row shrouded IDC connectors
  • Wires
  • 8-pin 1.27mm ribbon cable, and IDC connectors for each end (included with the Chainlink Driver boards I sell on Etsy)
  • 3.3v power wire
  • e.g. 22AWG solid hookup wire
  • 12v power/ground wires
  • 20AWG up to 14AWG depending on number of modules
  • 12V Power supply (see appendix for more info)
  • ESP32
  • The TTGO T-Display [affiliate links help support this project at no cost to you, or use a non-affiliate link if you’d prefer] is the recommended ESP32 board, which includes a 240x135 LCD that the splitflap firmware supports out of the box. (Also available on aliexpress, which may be cheaper)
  • An optional Chainlink Buddy [T-Display] is also highly recommended for most users, which makes it easy and clean to connect a T-Display to the Chainlink Driver.
  • If you want to use an ESP32 module other than a T-Display, a Chainlink Buddy [Breadboard] may be helpful in lieu of the T-Display Buddy. See the appendix for more info on using other ESP32 modules.

2. Finish assembling the PCB

  • Insert and solder the connectors as shown. Note that both of the IDC connectors on the ends face the same way - notches facing left.
  • Insert the ribbon cable into a connector as shown, and gently clamp shut with a vise or pliers. Repeat with the other connector on the opposite end, making sure that both connectors face the same way - notches facing left.
  • Not recommended, but you can optionally install the strain relief on the connectors (included with Bezek Labs Chainlink Driver boards): fold the ribbon cable back over the connector and install the plastic piece to clamp it down until it clicks. You’ll sacrifice some cable length and end up with a bulkier/taller connector, so I don’t think it’s worthwhile, especially since your cables shouldn’t be moving around much anyway.

3. Assemble the Chainlink Buddy

  • Solder the connectors into place (make sure the IDC connector notch faces the left, as indicated on the PCB)

T-Display Buddy

On the T-Display itself, you will solder the 2 rows of male headers (included in the box) to the T-Display, and then the whole module will plug into the matching female headers you soldered on the Buddy board.

You may notice a few empty spaces in the lower left of the T-Display Buddy PCB labeled C1 and C2 along with 3 through-holes; don’t worry, those are optional components and not needed for a basic setup. See Standalone T-Display operation for more info.

Note: the T-Display often comes with a small Red/Black wiring harness with connector as well; it is unused with the Chainlink Buddy and can be discarded.