Freely translated from Chinese documents © 2015 DWIN Technology.
This document © 2018-2021 Sebastien Andrivet.

0. Introduction

DGUS and MINI DGUS

DGUS (DWIN Graphic Utilized Software) is a cost effective GUI platform developed by DWIN Technology. MINI DGUS LCM (Liquid Crystal Monitor) is a low-cost and smaller module with DGUS firmware pre-installed, with the same development method as the other DGUS LCM.

The differences between MINI DGUS and DGUS are listed below:

• Low cost ARM MCU application with low power consumption
• Memory space from 256MB to 128MB
• Variable space from 56KB to 4KB
• Number of curves buffer from 8 to 4 or 2

In this version some functions have been excluded, among them the CRC Checksum, firmware update using SD card, user-defined baud rate, Firmware Parameter Config setting, Timer Variable and DWIN OS.

There is also a DGUS II which is another generation of the DGUS (not the DGUS MINI). Examples of such MINI DGUS panels are:

• DMT48270M043_05WT
• DMT48270M043_02WT

This document

This document is freely translated from the Chinese document MINI DGUS 屏用户开发指南 (Version 2.3 2015.08) with some information taken from other documents such as the English DWIN DGUS Display Development Guide Version 4.3 and some of my own researches.

As I found the original order of chapters confusing, this document uses a different order. Pictures are my own.

Note: I am not affiliated directly or indirectly to DWIN Technology nor endorsed by them. This is my own work for my own purpose (I am developing a firmware for a 3D printer using a MINI DGUS Display). USE IT AT YOU OWN RISK.

SDKs

There are several versions of the SDK available. Some are for the latest version of the hardware (i.e. DGUS II), some for DGUS and DGUS MINI. Some are translated in English, some only partially. For DGUS MINI, I found that the following SDK works relatively well:

• DGUS SDK 5.10

More recent versions (like 7.x or 8.x) may work but are, in general, only partially translated in English.

1. Flashing MINI DGUS Display with a microSD card

The MINI DGUS Display can be flashed by using its microSD slot (on the right):

1.1. Formatting the microSD card

IMPORTANT: You have to use a microSD card with a maximum capacity of 8GiB. If you use a microSD card with a greater capacity, the results are unreliable (sometimes it flashes, sometimes not). This is a limitation of the MINI DGUS Display.

The microSD card has to be formatted with the following parameters: FAT32 4096 bytes per cluster (i.e. 8 sectors)

To format it under Linux (and macOS with the dosfstools Homebrew package):

mkfs.fat -F 32 -n SD -s 8 -v /dev/diskN

Of course, replace /dev/diskN with the appropriate value.

To format under Windows (Command Prompt):

format G: /FS:FAT32 /V:LCD /A:4096 

Of course, replace G: with the appropriate volume letter.

1.2. DWIN_SET folder

All files are placed in a DWIN_SET folder, itself in the root of the SD card. These files are typically:

1.3. CONFIG.TXT Configuration File

Some system settings can be configured by creating a CONFIG.TXT file inside the DWIN_SET folder. This is a simple text file with the following format:

R?=HH ; a comment

• R? is the identifier of the register (such as R0)
• HH is the value in hexadecimal (in capital)
• ; is optional and everything after it is ignored

For example

R1=07      ; baudrate:115200
R2=0D      ; FBZ|L22_Init_En|TPSAUTO
R3=5A      ; UART_SYNC_H
RA=A5      ; UART_SYNC_L

Important: The default values for UART_SYNC_H and UART_SYNC_Lare 5A and A5.

SD Card Config Register

The configuration file parameters are one-byte HEX values (must be capitalized), such as 0A for decimal 10. The parameters of the configuration file must have 2 digits, for example 00 cannot be written as 0.

R0 (drive mode, i.e. resolution)

IMPORTANT: Users are not supposed to configure this parameter.

MINI DGUS Display drive mode selection. Configuration error will lead to abnormal display (distorted images).

For information, the modes are defined as:

R1 (baud rate)

Serial port 1 baud rate setting. Default baud rate is 115200.

R2 (SYS_CFG)

R3 (UART_SYNC_H)

Frame header. R3 is the first byte of the frame header (high order byte). RA is the second byte of the frame header (low order byte).

R4 (bit clock phase)

IMPORTANT: Users are not supposed to configure this parameter.

Due to TCON difference on display, there are two kinds of initial displaying data and R4 is used to setting the timing relation of the input data and clock:

• R4=00 The input data is locked at the rising edge of clock
• R4=FF The input data is locked at the falling edge of clock

R5 (custom baud rate)

• When R1 is between 0x00 and 0x10, R5 and R9 are unused.
• When R1 is equal to 0x11, R5 and R9 define the baud rate:

baudrate = 6250000 / R5:R9

For example, if R5=0x02 and R9=0x71, the corresponding baud rate is 10000bps:

R5:R9 = 0x0271 = 625
baudrate = 6250000 / 625 = 10000bps

R6, R7 and R8

These three registers control the back light if TP_LED (register R2 bit 5) is set to 1.

Example:

R2.5=1, R6=40, R7=10, R8=1E: If there is no touch within 30 seconds (0x1E = 30), brightness will go down to 25% (0x10). It will go back to 100% (0x40) if the user press the screen.

R9 (custom baud rate)

See R5.

RA (UART_SYNC_L)

See R3.

RB (reformat)

IMPORTANT: This is not documented in the original Chinese document. If you create a CONFIG.TXT file in the DWIN_SET directory with content:

RB=5A

it reformats the LCD display: all the images are erased and the default settings of the LCD are loaded. During the process, the screen becomes blue. When the process is finished, it becomes white-gray.

1.4. Flashing

Insert the microSD card inside the slot of the MINI DGUS Display (on the right side in this picture):

The display turns blue and the flashing process begins. After a few seconds, every image is displayed one by one. When the sequence of images stops, you can remove the microSD card and power-off / power-on the display.

1.5. MINI DGUS Display Calibration

Method 1 - Press quickly the display

Tap very quickly on an area of the display that is not a button. You have to tap 20 times in less than 4 seconds. When entering calibration mode, the display emits a long beep and turns blue.

Follow the instructions on the screen (such as Press The Cross Dot In Left_Top.) and when it is finished, the display returns to the starting page.

Method 2 - TP_CORRECT

Add a line with TP_CORRECT in the CONFIG.TXT file inside the DWIN_SET folder. Then place the microSD card in the slot (like for flashing). When entering calibration mode, the display emits a long beep and turns blue.

Follow the instructions on the screen (such as Press The Cross Dot In Left_Top.)

When the calibration is done, remove the microSD card and then remove the TP_CORRECT line in the CONFIG.TXT file.

Note: Some documents (from DWIN) indicate to create a CONFIG.TXT in the root of the microSD card. From my own tests, this is wrong. The file has to be in the DWIN_SET folder.

1.6. SD Interface Lock & Unlock

Lock

To disable the SD card, write SD_LOCK_1000_12345678 in CONFIG.TXT and plug the microSD card into the DGUS module. In this example, 1000 is the address of the password in SRAM (0x0000-0x3FFF), 12345678 is the password to reenable the SD slot (8 bytes).

Unlock

• Method 1: Send the password via the serial port: A5 5A 0B 82 10 00 31 32 33 34 35 36 37 38 (command 0x82 - Write SRAM - at address 0x1000).
• Method 2: Typing the password via a ASCII Text area
• Method 3: Write SD_UNLOCK_12345678 in CONFIG.TXT

WARNING: Failure to input correctly the password will definitively lock the SD slot.

2. Data Formats

The MINI DGUS Display uses these formats to represent data:

• All values are in Big Endian
• Decimal numbers are represented by fixed-point decimals. For example 0x4D2 (1234) represents 12.34 if there are 2 decimal deigits.
• The MINI DGUS display software uses a 65K color system, with 16 bits:
  • Bits 0-4: Blue
  • Bits 5-10: Green
  • Bits 11-15: Red

3. Memory Spaces

The MINI DGUS Display uses different spaces for permanent or temporary storage of data:

Note: 02 series have only 4 KW of RAM for Variables (0x0000 to 0x07FF).

3.1. Libraries

The 32 MB of flash memory for Libraries are divided into 128 blocks of 128 KW (256 KB):

3.2. Pictures

The MINI DGUS Display uses 96 MB of Flash memory to store 350 pictures. The images have the following format:

• BMP (Windows 3.x Bitmap)
• 480 x 272 pixels
• 24 bits per pixel (3 x 8 bits, no alpha)
• Bottom-up bitmap

The last point is very important. The LCD (i.e. DGUS) is not able to handle other formats like top-down bitmaps. To convert images to the right format, you can use the Image Converter provided with the DGUS SDK or image editors such as Photoshop. You can also use ImageMagick:

convert 180.bmp -resize 480x272 BMP3:180.bmp

To convert all images:

for f in *.bmp; do convert "$f" -resize 480x272 BMP3:"$f"; done

3.3. Registers

The MINI DGUS Display provides 256 registers used to control the behavior of the system:

Notes:: Sizes are in words (2 bytes). * All values are in Big Endian

3.4. Variables

The MINI DGUS Display provides 8 KW/16kB (05 series) or 4 KW/8kB (02 series) of RAM for storing GUI variable data. The address range is 0x0000-0x3FFF. Each address represents a word (2 bytes, in big endian order).

Variable memory space is accessed using 0x82/0x83 commands.

3.5. Curve data buffers

In order to simplify the display of the real-time curves, the MINI DGUS Displays have a curve data buffer for buffering the user's curve data. This buffer does not occupy the data memory space and can buffer up to 4 curves at the same time (2 for 02 series).

Curve data buffer is accessed using 0x84 commands (write only).

Curve data buffer can only be written in words, and the data for each curve point is represented by a 2-byte signed integer. It is possible to clear the first and second curves by writing 0x5A or 0x5B to the 0xEB register.

4. Serial ports

The MINI DGUS Displays are equipped with two (05 series) or one (02 series) asynchronous, full-duplex serial ports (UART). Each byte occupies 10 bits: 1 start bit, 8 data bits, 1 stop bit and no parity (8N1).

The serial port 1 baud rate is configured by the SD card, and the serial port 2 (if present) is fixed to 115200 bps.

The serial port 1 and serial port 2 use the same frame structure. All data are transferred in MSB order, i.e. to transfer 0x1234, 0x12 is transferred first then 0x34.

4.1. Differences between ports 1 and 2

4.2. Data Frames

Data frames consist of up to 4 blocks as described in this table:

Notes: The default values for R3 (UART_SYNC_H) and RA (UART_SYNC_L) are 5A and A5. So the frames begin with the bytes 5A A5. * All values are in Big Endian. The maximum data length that can be transmitted is 248 bytes. It is not clear if MINI DGUS Displays are able to support CRC like DGUS displays. Some parts of the documentation suggest it is the case, but the data sheets suggest the contrary. I have assumed that MINI DGUS displays do not support CRC.

4.3 Commands

REG is between 0x00 and 0xFF and designates the first register to read of write. LEN is between 0x00 and 0xFF and designates the length (in bytes) of the data to read or write. DATA is the sequence of bytes to write or returned by the MINI DGUS Display.

ADDR is between 0x0000 and 0x3FFF and designates the address of the first word to read of write. LEN is between 0x00 and 0x7F and designates the length (in words) of the data to read or write. DATA is the sequence of words to write or returned by the MINI DGUS Display.

CH_MODE defines the channels order. Each bit of CH_MODE corresponds to a channel: Bit 0 corresponds to channel 0, and bit 1 corresponds to channel 1, ... Each bit set (1) in CH_MODE indicates that DATA contains data for the corresponding channel. For example if CH_MODE is equal to 0x0B, DATA has the following format: (channel0|channel1|channel3) | ... | (channel0|channel1|channel3). Each channel data is a 16-bit unsigned integer.

5. Touch Configuration / Inputs (13*.BIN)

The Touch Configuration File (13*.BIN) contains touch (input) commands and can be generated with the DGUS SDK. Each command occupies 16, 32 or 48 bytes and include 6 parts:

Overview of Commands

5.1 Variable Data Input (0x00)

Valid key codes

5.2. Popup Menu (0x01)

5.3. Incremental Adjustment (0x02)

5.4. Slider Adjustment (0x03)

Note: To prevent maloperation, you must press the effective drag area for more than 0.5 seconds before sliding starts

5.5. RTC Settings (0x04)

5.6. Return Key Code (0x05)

5.7. Text Input (0x06)

5.7.1. Key code table for text input

The Key Code consists of 2 bytes. The low byte indicates lower-case letter, the high byte indicates capital letters.

Note: Key code should be less than 0x80 (ASCII). Key code 0x0D is automatically translated to 0x0D 0x0A. 0x00 and 0xFF are disabled.

5.7.1. Function keys

Note: When using the keyboard (key code saved in the 0x4F register) for text entry, if you use the Caps Lock key, define the animation area of the button as needed.

6. Variables Configuration / Display (14*.BIN)

The Variables Configuration File (14*.BIN) contains variables commands (i.e. display command) and can be generated with the DGUS SDK. Each command occupies 32 bytes and each page contains space for 64 variables commands. Variable commands contains 6 parts:

Overview of Commands

6.1. Variable Icon (0x00)

6.2. Animated Icon (0x01)

Note: If the value in VP address is equal to neither V_Stop nor V_Start, the icon is not displayed.

6.3. Slider (0x02)

6.4. WordArt (0x03)

6.5. Image animation (0x04)

Notes:

• The starting picture position must be less than the ending picture position
• If you also set a picture animation variable on the Pic_End page, you will be able to replay continuously
• Send a command through the serial port or use a touch command to end the animation

6.6. Icon Rotation (0x05)

Note: Rotation is clockwise

6.7. Bit Variable Icon (0x06)

Display_Mode

Move_Mode

6.8. Data Variable (0x10)

6.9. Text (0x11)

Note: Font_Y_Dots must be 2 * Font_X_Dots. The 0# font library is pre-loaded by the DGUS Display (file 0_DWIN_ASCII.hzk) and contains all ASCII characters in 4 * 8 - 64 * 128 dots matrices.

6.10. RTC (0x12)

Digital RTC

RTC Code Table

Examples:

• Y-M-D H:Q:S 0x00 -> 2012-05-02 12:00:00
• M-D W H:Q 0x00 -> 05-02 WED 12:00

Analog Clock

6.11. HEX (Timer) Variable (0x13)

Every time a Timer data (BCD code) is read, one ASCII character will be added as a seperator.

Special characters:

• 0x00: None, Timer data will be concatenated
• 0x0D: new line

6.12. Real-time curve (0x20)

• VD_Central is typically the average between Vmax and Vmin.

• For a full scale curve:

        Ye - Ys
MUL_Y = ----------- * 256
        Vmax - Vmin

• Example for a 12-bit AD data acquisition, displayed full scale between Ys=50 and Ye=430:

Vmin = 0
Vmax = 4095
MUL_Y = (430-50) * 256 / 4095 = 23.7 rounded down to 23

6.13. Basic Graphic (0x21)

Variable data format

Data

• Icon: High byte of command (XX) specifies the address of the icon file. Display mode is transparent.