320×240 Graphic LCD 4.72" Industrial Blue - MCU
DM-LCD320240-479 is a 320×240 monochrome graphic LCD module with an STN negative blue transmissive display, white LED backlight, RA8835 controller, and parallel MPU interface.
The module uses a 1/240 duty drive, a 6:00 viewing direction, a 95.98×71.98 mm active area, and a 139.0×100.0×13.1 mm maximum outline. The published interface supports 8080- and 6800-family host buses through the documented signal configuration.
Document use: Use the DM-LCD320240-479 datasheet for module dimensions, pin assignment, optical data, electrical limits, and environmental conditions. Use the RA8835 specification for controller commands, timing, memory access, and display-control functions.
Verified Technical Specifications
The table lists the published module specifications used for mechanical, optical, electrical, and environmental review.
| Parameter | Specification |
|---|---|
| Model | DM-LCD320240-479 |
| Display Type | Monochrome graphic LCD module |
| Resolution | 320×240 dots |
| LCD Mode | STN negative, blue, transmissive |
| Viewing Direction | 6:00 |
| Duty | 1/240 |
| Active Area | 95.98×71.98 mm |
| Viewing Area | 104.0×79.3 mm, as shown in the mechanical drawing |
| Pixel Pitch | 0.30×0.30 mm |
| Module Outline | 139.0×100.0×13.1 mm maximum; the drawing specifies ±0.5 mm on the 139.0 mm and 100.0 mm outline dimensions |
| Backlight | White LED |
| Controller IC | RA8835 |
| Host Interface | Parallel MPU interface with 8-bit data bus |
| Supported MPU Families | 8080 and 6800 families, according to the module pin table and RA8835 interface specification |
| Operating Temperature | -20°C to +70°C |
| Storage Temperature | -30°C to +80°C |
Optical, Electrical and Mechanical Details
These values separate the logic supply, LCD drive requirement, backlight input, and optical test conditions so they can be reviewed independently during PCB and enclosure design.
Separate Power Domains
The 5.0 V value is the typical logic supply and the typical backlight supply. LCD contrast also depends on the VDD-VO drive voltage and the VOP adjustment circuit shown in the module datasheet.
The recommended circuit shows a 10 kΩ to 20 kΩ variable resistor connected between VDD, VO, and VEE for contrast adjustment on the host board.
Logic Supply
VDD-VSS: 4.5 to 5.5 V, 5.0 V typical. Supply current at VDD = 5.0 V is 52.2 mA minimum, 52.4 mA typical, and 52.8 mA maximum.
LCD Drive Voltage
VDD-VO at 25°C: 21.0 to 22.2 V, 21.6 V typical. The host board must provide the documented VOP adjustment circuit.
White LED Backlight
Backlight supply: 4.9 to 5.1 V, 5.0 V typical. Backlight current: 40 to 160 mA, 128 mA typical at 5.0 V.
Optical Values
Contrast ratio: 3:1 typical. Rise time: 200 ms typical, 300 ms maximum. Fall time: 250 ms typical, 350 ms maximum.
Backlight Luminance Test
450 cd/m² minimum and 560 cd/m² typical at ILED = 128 mA. The datasheet identifies this value as luminance measured without the LCD layer.
Specified Viewing Angles
At contrast ratio ≥2: top 20° maximum, bottom 40° maximum, left 30° maximum, and right 30° maximum.
Connector and Parallel Interface Details
The module documentation lists CON1 and CON2 pin arrangements. Review the exact connector option, mating hardware, and host-bus selection before PCB release.
8-Bit Parallel MPU Bus
DB0 through DB7 carry data between the host and the RA8835. WR, RD, CS, A0, and RES provide write/read timing, chip select, command/data selection, and controller reset.
The RA8835 supports 8080- and 6800-family interfaces. On CON2, SEL1 is documented as high for 6800 mode and low for 8080 mode.
The mechanical drawing shows 2.54 mm connector pitch. CON1 is a 20-pin connection and CON2 is an 18-pin connection.
RA8835 Controller Functions
The RA8835 specification defines the controller functions available to firmware. The final initialization sequence, display-memory mapping, timing, and screen layout must be validated for the 320×240 module.
Text and Graphics
Supports text, graphics, and combined text/graphics display modes.
Layered Screens
Supports up to three overlapping screens in graphics mode, controlled by firmware and display-memory configuration.
Cursor Control
Provides programmable cursor form, direction, position, and display-layer controls.
Scrolling
Provides horizontal, vertical, on-page, inter-page, and bidirectional scrolling functions.
Published Reliability Test Conditions
The following conditions are listed in the module datasheet for product-level reliability review. They are test conditions, not a replacement for final equipment qualification, regulatory testing, or enclosure-level validation.
Engineering Review Before Sample Approval
Confirm the mechanical, electrical, optical, and firmware details below with the final host PCB, enclosure window, cable or connector, and operating environment.
Production Document Order
Use the latest module datasheet and drawing for the exact ordered model. Use the RA8835 specification for controller commands and timing. Confirm any project-specific modification on the approved drawing before production release.
Mechanical fit: Verify the 139.0×100.0 mm outline, 13.1 mm maximum depth, 104.0×79.3 mm viewing area, mounting holes, connector clearances, and enclosure window.
Logic compatibility: Check the host I/O levels against VIL ≤0.2VDD and VIH ≥0.5VDD, without exceeding the module input limits.
Contrast circuit: Include the documented VOP adjustment path for VO and VEE instead of treating the module as a single 5 V load.
Backlight drive: Design for the specified voltage and current range and approve the final brightness through the LCD, enclosure window, and intended ambient lighting.
Bus selection: Confirm 8080 or 6800 mode, the selected connector, SEL1 state where applicable, signal timing, reset timing, and PCB pin order.
Firmware validation: Confirm SYSTEM SET parameters, display-memory addresses, cursor behavior, overlay mode, scrolling behavior, and read/write timing on the final hardware.
Common Questions Before Ordering
Is 5.0 V the only voltage required?
No. The logic supply and backlight supply are each specified at 5.0 V typical, while LCD contrast requires the documented VDD-VO drive voltage and VOP adjustment circuit.
Does the module support both 8080 and 6800 buses?
Yes. The module pin descriptions and RA8835 specification document both bus families. CON2 uses SEL1 high for 6800 mode and low for 8080 mode.
Is 560 cd/m² the finished LCD surface luminance?
No. The module datasheet labels 560 cd/m² typical as a backlight luminance measurement without the LCD layer at ILED = 128 mA.
What connector arrangements are documented?
The module datasheet lists a 20-pin CON1 connection and an 18-pin CON2 connection. The mechanical drawing specifies a 2.54 mm pitch. Confirm the selected connector arrangement and mating hardware before PCB release.
Can generic RA8835 example settings be used directly?
Controller examples are reference material. The final settings must match this module's 320×240 resolution, 1/240 duty, memory configuration, scan timing, connector wiring, and approved contrast settings.
Which document controls production release?
Use the latest DM-LCD320240-479 datasheet and approved mechanical drawing for the module. Use the RA8835 specification for controller behavior, commands, timing, and display-memory operation.
Download Official Technical Documents
Use the module datasheet to confirm dimensions, pin assignment, electrical characteristics, optical test conditions, and reliability data. Use the RA8835 specification for controller commands, MCU timing, scrolling, cursor control, and memory access.