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Chesstimation

This project uses ESP32 hardware to connect an old Hegener+Glaser Mephisto Modular chess computer (Modular, Exclusive or München Board) to a computer or a smart phone.

Main Features:

• No modification to original Mephisto Modular/Exclusive/München board required. Just replace the old modules with the new one!
• 3.5" Color-TFT (480x320 Pixels), available space is perfectly used.
• Modern, intuitive touch control
• Current position is shown on the display.
• Both White and Black can be played from the front.
• All opponent's moves are displayed via the board's LEDs.
• Power supply via built-in battery that can be charged via USB-C (with 2200 mAh lipo >7h running time, ~4h charging time).
• Communication with PC via USB-C, Bluetooth Classic or BLE (Bluetooth Low Energy).
• Playing completely without cables is possible!
• All settings and the board position are not lost when the device is switched off!
• Switching on and off takes less than 2 seconds.
• Certabo or Millennium Chesslink can be selected as emulation, making it compatible with many chess programs:
  • "White Pawn" on iPhone and Android (https://khadimfall.com/p/white-pawn)
  • "Chess for Android"
  • "Chess Dojo App" for Android
  • BearChess (http://www.solanosoft.com/index.php?page=bearchess)
  • original Certabo Software (https://www.certabo.com/)
  • Lucas Chess (https://lucaschess.pythonanywhere.com/index?lang=en)
  • and via Graham's DLLs (https://goneill.co.nz/chess.php) actually all software that can handle DGT boards.

Limitations:

• Pawn promotion currently to queen only.
• Captured piece needs to be removed from board before capturing piece is put to the square.
• Must not be combined with other modules or power supplies.

Contact & Donation:

If you like this project you may contact me via chesstimation@kabelmail.de

I would also be happy to receive a donation.

Following hardware components are required:

1. Wemos LolinD32 (https://de.aliexpress.com/item/32808551116.html)
2. 40-pin edge card connector, e.g. https://de.aliexpress.com/item/33035971298.html (you need to select 2x20 Pin)
3. Rainbow Ribbon Cable (~30cm) with 1.27mm spacing, e.g. from Aliexpress: https://www.aliexpress.com/item/1005002509747445.html (you need to select 1.27mm spacing and 40 pin!)
4. Waveshare 3.5 inch TFT Pico Res Touch display: https://www.waveshare.com/pico-restouch-lcd-3.5.htm, e.g available here: https://eckstein-shop.de/WaveShare35inchTouchDisplayModuleforRaspberryPiPico2C65KColors2C480C3973202CSPI
5. Micro USB soldering plug (https://www.aliexpress.com/item/33060931097.html) and USB-C female soldering connector (e.g. https://www.aliexpress.com/item/1005002292881776.html)
6. optionally lipo battery with plug for Lolin D32, e.g.: https://www.aliexpress.com/item/1005001310592871.html (you need an extra JST PH 2.0mm plug for this battery, e.g. https://www.aliexpress.com/item/1005001315857869.html Double-check polarity of plug with + and - signs on PCB of Lolin!)
7. Micro-Switch (built into bottom of module) to switch off module completely (https://www.aliexpress.com/item/4001202080623.html Choose MSS-22D18 type!)

How to connect the 40-pin plug to the Mephisto board?

If you look at the chessboard or module from the front, the upper row of contacts is numbered from left to right from 1 to 39, the lower row from 2 to 40. With the ribbon cable connector as linked above the wires are numbered a bit different, from left to right: 2,1, 4,3, 6,5, 8,7, ... 40,39. This has already been considered in below table and you will be able to connect the 8 data wires just in parallel to the Lolin D32.

40-pin Connector Pin	LolinD32 Pin
1+2	BAT
39+40	GND
15 / D0	GPIO 12
16 / D1	GPIO 13
17 / D2	GPIO 27
18 / D3	GPIO 14
19 / D4	GPIO 25
20 / D5	GPIO 26
21 / D6	GPIO 32
22 / D7	GPIO 33
29 / LDC_LE	GPIO 2
30 / ROW_LE	GPIO 15
31 / CB_EN	GPIO 4
32 / LDC_EN	GPIO 0

How to connect the 3.5" display to Lolin D32

TFT Display Pin	LolinD32 Pin
VSYS	BAT
GND	GND
LCD_DC	GPIO 17
LCD_CS	SS/GPIO 5
CLK	SCK/GPIO 18
MOSI	MOSI/GPIO 23
MISO	MISO/GPIO 19
LCD_BL	GPIO 16
LCD_RST	RST(RESET)
TP_CS	GPIO 21
TP_IRQ	GPIO 34

Software development environment

Software development is done in C++ using:

• Visual Studio Code
• Platform IO

In Platform IO you need to install 2 additional libraries for this project:

• LVGL 8.3.4 (you need to use Chesstimation's lv_conf.h)
• TFT eSPI 2.5.2 (you need to use Chesstimation's as User_Setup.h and User_Setup_Select.h)

For flashing the firmware to the Lolin D32 without Platform IO I use ESP Flasher: https://github.com/Jason2866/ESP_Flasher/releases