New release ready

Need some time to review Release 1.1. Some new things are coming along, just have a quick preview here.

• PCF8563 RTC with 10 minutes tantalium capacitor backup power
• 4 layer PCB with better routing and right placement of FPC
• RESE switch. It will enable use also another models of epaper in case you want to use it just as a controller
• Sorry but probably not white, since making it that color with 4 layer, means that it will cost like 40 USD more. Who cares about the color, anyways? Well me but is not the most critical thing. Stay tuned, make preorders, while I reorganize the chicken-farm.

Bistable smart switich repository

Introducing the ESP32-C3 2.7-inch Touch Wall Switch Demo Kit, the latest product from Fasani Corp that will revolutionize your home automation experience! With its cutting-edge ESP32C3 chip and GOOD DISPLAY's hot-selling 2.7-inch electronic paper display with touch screen GDEY027T91-T01, this kit allows you to easily control various devices in your home. Equipped with a stable and reliable 220AC2DC module and Grove I2C connectors, you can connect I2C sensors for more intelligent functions. The 4-layer PCB design ensures stable signal transmission, making it more durable and reliable. This demo kit supports RESE switches, which allows you to freely choose different types of electronic ink screens and achieve more customized features. It also includes the PCF8563 RTC real-time clock module, with a 10-minute capacitor backup power supply to ensure that the clock never fails due to power outages. Get this kit today and make your home smarter, more convenient, and efficient!

Why did I made this

There is actually not any existing PCB on the market this days where you get Epaper controller plus touch for cheap SPI epapers. There are of course epaper controllers with touch but for ready-made products with parallel epapers such as Kindle and any other e-book reader. But what if you want to make a simple UX using a small SPI epaper?

This board gives an answer to this question and opens a new way to explore that possibility. This ESP32-C3 controller board includes in a single PCB the existing SPI adapter for 24 pin epapers and an additional I2C connector for touch. Based on my already working PCB to have a small footprint SPI driver and Tinypico HAT this new project has the size to be used in a home swich. But of course it's not limited to be used in a home switch but in any other project where you would like to try making easy and straight-forward UX. It has connectors ready to drive a 2.7 inch E-Ink Screen Display 264x176 epaper display. There is a new model that has touch and I can include it in this package optionally (Check product options)

As a resume what you get with this PCB:

• Low consumption controller for 24 FPC epaper displays (No LEDs, no additional consuming devices)
• 6 FPC touch connector already routed to I2C in the C3 (SDA: IO5 SCL: IO4) with pull-ups already in place
• Size ready to comb the epaper display and place it safely in the other side with some double sided tape
• USB to UART chip CP2102N (QFN28) with USB-C interface
• 3 Output IOs to control external devices: IO1, IO2 and IO3
• FREE 3D-printed in PETG or PLA material Prusament an EU wall switch where PCB Fits (Look at last image)

OPTIONALLY: You can get the 3D-printed switch case in PETG that you can see in last product pictures for free (White) just send me a message after buying the product.

What it does not have and is not planned to be included is Battery charging circuit since the idea it was to be used as a switch or industrial device where is always connected to a power source.

What it does not deliver in Revision 1.0 but is coming in release 1.1

• RESE switch is resistance is fixed to 3 Ω in next revision comes a switch to allow also epapers that use 4.7 Ω
• 5V VBUS input (Rel 1.1 you can power also using 5V, 1.0 only via USB)
• RTC PCF8563 which is tied to same I2C as touch but uses INT alarm pin with IO2
• Please check routing and schematics in the links provided below

It can be programmed connecting it directly to USB. And it can be powered either by USB or by 3.3V directly. It was designed to be used in home appliances more specifically in a switch to have a smart-home actuator where you can place switches or do whatever you desire UX wise having an epaper which has a touch interface. But you don't want to charge a switch and a battery to it when there is power running all over the house. We will provide soon an extra PCB, that converts 220 AC to 3.3 DC, which has an additional Latch Relay on board.

Note that this what I'm offering here is an early release that has 3 hardware small fixes done in the top of the PCB:

1. Re-routed SPI MOSI pin out of IO9 which is BOOT-MODE in this MCU and I was not aware of it (Now MOSI is IO0)
2. Re-routed DTR output from IO0 to IO9
3. Updated Resistance of IO8 since needs to be pulled-up in order to enter Download mode (so you can flash the MCU)

Hence price is reduced about 50% in this PCB. All this will be hopefully gone in REV 1.1 that you can check here: https://github.com/martinberlin/H-spi-adapters/releases/tag/1.1

You can also find in that repository on the folder C3-27-epaper-touch all design files, schematics, and components.

Full IO configuration for the switch example

# EPAPER SPI pins
    CONFIG_EINK_SPI_MOSI=0
    CONFIG_EINK_SPI_CLK=6
    CONFIG_EINK_SPI_CS=19
    CONFIG_EINK_DC=18
    CONFIG_EINK_RST=10
    CONFIG_EINK_BUSY=7

    # TOUCH I2C configuration
CONFIG_TOUCH_SDA=5
CONFIG_TOUCH_SDL=4
CONFIG_TOUCH_INT=8

INT pin is pulled-up and HIGH by default the touch controller triggers it LOW when there is a touch event to read.

Closed