Display Station 2024 Model A

Display Station 2024 Model A

The Display Station 2024 Model A (DS24a) is based on the ESP32-2432S028R, which provides an ultra low cost interface into your own compute.

Variation

There are other display devices on the market called ESP32-2432S028R, the DS24a is the ESP32-2432S028R version with a ILI9341 display.

Limitations

Due to the extreme lack of compute power and memory on this device, hacking the board takes a lot of time. Currently we need to multiplex some heavy apps so they can only run one at a time (e.g. Bluetooth radio and the LCD display). Also we do not have time to get some peripherals work:

  1. Speaker Amplifier
  2. MicroSD Card

Even with those limitations we still believe the DS24a will revolutionise the digital world by delivering, for the first time, compute that people can fully control and benefit from into their homes.

Supplier

There are many ESP32-2432S028R devices available online that are very similar to the DS24a, with names like Cheap Yellow Displays (CYD), Guition / Sunton Smart Displays etc. most have small differences with each other.

The original ESP32-2432S028R design probably come from Shenzhen Jingcai Intelligent 深圳市晶彩智能有限公司.

User Manual

Getting started 2.8 Inch.pdf (6.4 MB)

Schematic Files

Support Files

Hardware

The ESP32-2432S028R version we are referencing as DS24a here has the words "HW-458" printed on the circuit board.

Note:

  1. DS24a shown above is standing up vertically on low-cost plastic spacers for better display visibility and heat dissipation.
  2. DS24a does NOT have a battery interface.
  3. There is a Light Dependent Resistor (to measure surrounding light level) in the front Upper Right Corner of the board.
  4. DS24a's low cost screen means the displayed QR Code CANNOT be seen clearly at an angle (but for our use as an Activity Marker this is actually an advantage!).

1. Processor

Teh DS24a processor is built with the ESP-WROOM-32 module.

  • Dual-core ESP32-D0WDQ6 processor
  • 40MHz Crystal Oscillator
  • 4MByte Flash Storage
  • Meandered Inverted-F Antenna

Note:

  1. DS24a does NOT support the use of lower frequency crystal oscillators (e.g. 26MHz).
  2. DS24a does NOT take advantage of ESP-WROOM-32's ability to have external Flash (up to 4Mbyte) NOR have external RAM (up to 4Mbyte).

Pin-Outs

Despite its ultra low-cost, the ESP-WROOM-32 has builtin in Bluetooth and WiFi (with integrated antenna) with a rich set of input/output pins.

esp32-pinout-chip-ESP-WROOM-32
source: randomnerdtutorials

2. Display

This model has 2.8 inch ILI9341 SPI display with a resolution of 240x320 (portrait mode).

Details: ILI9341.pdf (3.3 MB)

To display images on the ESP32-2432S028R in Landscape (320x240) mode instead of the default Portrait mode (240x320), rotating the output by 270 degree before displaying the output.

Note we rotate output image by 270 degrees instead of 90 degrees, because we want the side of the board with IO connectors to be on top facing up and the plastic spacers (functioning as legs holding up the board) are attached to the side of the board without IO connectors at the bottom facing down.

Above shows DS24a acting as a Activity marker performing the TRIPLE role of

  1. a QR Marker (displaying QR Code)
  2. a Radio Marker (broadcasting Bluetooth signals)
  3. a Radio Scanner (scanning WiFi and Bluetooth signals)

3. Other Components

The DS24a is very expandable supporting a lot of different inputs and outputs.

esp32-2432s028

Below is a comprehensive of labelling of components of a similar model (which has some differences e.g. the audio IC is 8002A instead of 8002, it does NOT have a USB Type-C port, it does NOT have IO22 exposed on two IO connectors etc.).

esp32-2432s028
source: esp32_2432s028_pcb.pdf

Similar Models

Although there are many esp32 based display devices, the DS24a can only be a ESP32-2432S028R.

Our focus is on the ESP32-2432S028R model which has the best open software support, but there are a number of different models with a ESP-WROOM-32 chip and a touch display (which your local citizen ecosystem might support), most of these devices have the same display resolution of 240x320 but with different screen sizes, touch ability and connectors.

BECAREFUL some of the CYDs use Parallel interface (instead of the SPI interface) which is NOT support in ESPHome yet:

1. Screen Types

  • Non Touch - normally the cheapest
  • Resistive Touch - normally comes with a stylus
  • Capacitive Touch - normally the most expensive

DS24a has a Resistive Touch screen due to much lower cost than the Capacitive Touch screen.

2. Screen Sizes

There are similar boards with different features and screen sizes. Note all 3 boards listed below have battery interfaces that DS24a does NOT have:

2.2 inch - ESP32-2432S022

esp32-2432s022

2.4 inch - ESP32-2432S024

esp32-2432s024

2.8 inch - JC2432W328

jc2432W328

Software

Platform IO tends to dominate the low-end embedded device development space, for DS24a it is no exception.

The recommended LOW level development environment for DS24a is Platform IO:

The recommended HIGH level development environment for DS24a is ESPHome:

Note ESPHome is developed using Platform IO, so it uses Platform IO's list of board definitions.

ESPHome

  1. home-automation/ESPHome at master · eouthwaite/home-automation · GitHub
  2. ESP32-Cheap-Yellow-Display/Examples/ESPHome at main · witnessmenow/ESP32-Cheap-Yellow-Display · GitHub
  3. GitHub - GuySie/cyd-thermostat: ESPHome based thermostat controller for Cheap Yellow Display (CYD)
  4. GitHub - BOlaerts/ESP32-2432s028: Home Assistant integration using ESPHome on an esp32-2432s028 board, featuring I²C expansion and touchscreen functionalities

References

  1. ESP32 Cheap Yellow Display (CYD) Pinout (ESP32-2432S028R) | Random Nerd Tutorials
  2. ESP32-2432S028 | macsbug
  3. GitHub - rzeldent/esp32-smartdisplay: PlatformIO library LVGL Drivers for Sunton Smart display boards (CYD Cheap Yellow Display). This library supports these boards without any effort. ESP32-2432S024N/R/C, ESP32-2432S028R/C, ESP32-3248S035R/C, ESP32_8048S070N/C
  4. GitHub - witnessmenow/Spotify-Diy-Thing: Something similar to the Spotify Car Thing, built with a cheap ESP32 Screen
  5. ESP32-2432S028 - openHASP

IO Connectors

There are 3 white-coloured 4-pin IO connectors on the edges of the DS24a for attachment of external peripherals to varies input/output pins.

The DS24a comes bundled with only one 4-pin breakout cable for one of those 3 connectors, we suggest using the cable on the connector with the IO22 and IO27 pins for your input/output needs.

The other 2 connectors have pins that are also connected to other parts of the board, making usage more complex:

  • one connector has the serial TX/RX pins connected to the onboard USB serial chip.
  • one connector has the IO21 pin connected to the LCD backlight control.

Speaker

There is an onboard 8002 audio amplifier and speaker connection.

The quality can be substantially improved with hardware modifications.

LED

There are 3 LEDs clustered together on the back of DS24a, by default all 3 colours are turned ON, so it will emit a WHITE light as a whole. We need to turn one or more of the LEDs OFF get different colours.

RGB LED GPIO
Red 4
Green 16
Blue 17

The following colours are used to indicate the mode of DS24a:

  • White - Update Mode (firmware being updated)
  • Blue - Display Mode
  • OFF - Bluetooth Mode

MicroSD

MicroSD cards (also called TF cards) can be plugged into DS24a's onboard MicroSD slot (TF slot).

Note due to the sharing of the SPI bus getting it to work with OTHER peripherials can be difficult:

More background about this limitation with DS24a:

General usage of microSD with ESP32: