Brandon Roots
  • FILM
  • INTERACTIVE
  • ABOUT
  • CONTACT
April 11, 2022

Fractal Plant – Alpha Build

broots Homemade Hardware, ITP

Designing this board took considerably more time than I anticipated. I thought I was in a good starting place by having two reference designs from previous projects that repurposed Amazon Kindle displays and controlled them with an ESP32, Inkplate 6 and EPDiy.

My first hurdle was after realizing that both reference designs make use of various discontinued or “obsolete” components. My initial instinct was to locate these chips, such as the TPS65186, from one of the less familiar suppliers on Octopart. After some fruitless back and forth with Win Source Electronics I was able to locate another chip, the TPS65185, that IS actively being produced with what appears to be similar enough functionality.

The last week has been a series of these kind of struggles, looking for similar enough components as I rebuild the board functionality in my own Eagle project.

After much labor here is the schematic.

The board makes use of an ESP32 WROVER module as well as an I/O Expander to accommodate the many data lines needed to control the EINK display.

I had initially hoped to use an ESP32 S2 mini because of the integrated USB functionality but the reference designs both make use of a WROVER module and remapping the pinout proved exceedingly difficult.

To handle USB to UART for programming I have included a CP2102 chip and an upward facing USB-C connector.

This has been the most complex board I have designed in Eagle and I will hopefully find some help to review the schematics before placing an order through OSHPark or JLCPCB.

Fractal Plant – Final Project Proposal Fractal Plant – Boards Ordered

Related Posts

Fractal Plant – Foiled by  Registers

Homemade Hardware, ITP

Fractal Plant – Foiled by Registers

Since receiving the PCBs and successfully soldering the board together I have been trying to rewrite code for the I2C port expander. This has been immensely difficult! The Inkplate Arduino Library makes considerable use of an “Mcp” class, which is written to work with the MCP23017 GPIO expander IC. These chips are quite difficult to […]

Fractal Plant – Beta Build

Homemade Hardware, ITP

Fractal Plant – Beta Build

The boards arrived! Amazingly within an hour of one another. Based on the experience I think that JLCPCB is a better value. With shipping OSHPark was $55.50 for 3 boards. JLCPCB was $26.36 for 10 boards. Aside from a higher cost OSHPark also left sharp bits of tabs around the edges of the boards which […]

Fractal Plant – Boards Ordered

Homemade Hardware, ITP

Fractal Plant – Boards Ordered

Over the last week I rerouted the traces in my PCB design. Following feedback during class that the auto-router feature in Eagle isn’t very smart I did manage to make some cleaner routing manually. As part of the process I went through each component and made sure they were placed a closely as possible to […]

Recent Posts

  • Fractal Plant – Foiled by  RegistersFractal Plant – Foiled by Registers
    May 9, 2022
  • Fractal Plant – Beta BuildFractal Plant – Beta Build
    April 24, 2022
  • Fractal Plant – Boards OrderedFractal Plant – Boards Ordered
    April 18, 2022
Brandon Roots
Accessibility by WAH