SAM9x75 Curiosity With 5" maXTouch® Technology LVDS LCD + 3x SPI Round LCD
Introduction
This multi-display solution leverages a single SAM9X75 microprocessor unit (MPU) to efficiently drive multiple display types.
The integrated Extended LCD Controller (XLCDC) within the SAM9X75 directly controls a 5-inch Low-Voltage Differential Signaling (LVDS) display, providing high-resolution and robust graphical output. In addition, the MPU simultaneously manages three round LCDs via a single Serial Peripheral Interface (SPI) port, enabling flexible and synchronized content delivery across all displays.
This architecture demonstrates the SAM9X75’s capability to support both high-bandwidth LVDS displays and multiple SPI-driven LCDs in a unified, cost-effective embedded system.
Figure 1: Hardware Setup with custom interface boards
Hardware Setup
The hardware can also be assembled using publicly available Microchip parts and off-the-shelf components. The required hardware is listed below.
Required Hardware
| Hardware | Part number/link |
|---|---|
| SAM9x75 Curiosity Development Board | EV31H43A |
| 5" LVDS WVGA 800 x 480 maXTouch® Technology Display module | AC69T88A |
| (3) 240x240 Round SPI LCD | Waveshare® 1.28-inch round LCD |
| Micro USB or 5V power adapter for SAM9x75 Curiosity power supply | |
| FAT32-formatted microSD™ card for firmware binaries | |
| Jumper wires to connect SPI displays with SAM9x75 Curiosity board |
Assembly Instructions
- Connect the 5" LVDS WVGA maXTouch display module to the SAM9x75 Curiosity board using the steps in "Hardware Guide for SAM9x75 Curiosity with 5" LVDS WVGA maXTouch® Technology Display Module".
- Use jumper wires to connect the three round LCD displays to the Raspberry Pi® interface (J27) on the SAM9x75 Curiosity board.
| Signal Name | SPI Display | SAM9x75 Curiosity Pin on Raspberry Pi interface (J27) | Alternative - J25 mikroBUS1 |
|---|---|---|---|
| MOSI** | DIN | Pin 19 (PC22) | Pin 6 |
| SCK** | CLD | Pin 23 (PC26) | Pin 4 |
| D/C** | DC | Pin 3 (PC0) | Pin 11 |
| Reset** | RST | Pins 1, 17 (3.3V) | Pin 7, (3.3V) |
| Backlight** | BL | Pins 1, 17 (3.3V) | Pin 7, (3.3V) |
| CS0 (Display 0 CS) | CS | Pin 24 (PC25) | |
| CS1 (Display 1 CS) | Pin 35 (PB15) | ||
| CS2 (Display 2 CS) | Pin 12 (PB26) | ||
| VCC** | VCC | Pins 1, 17 (3.3V) | Pin 7, (3.3V) |
| GND** | GND | Pins 39, 25, 34 (GND) | Pin 8, 9 (GND) |
Microchip Graphics Suite (MGS) Project Examples
The following project examples can be used for this multi-display solution.
MGS Quickstart (project, binaries)
The MGS Quickstart application example serves as an entry point for developing multi-display Graphical User Interfaces (GUIs) using MGS Harmony. This example leverages MGS Composer to design individual screens tailored for each connected display. In the MGS Composer environment, each design layer is specifically assigned to a target display, enabling seamless management and customization of content across multiple screens, as illustrated in Figure 2.
Figure 2: MGS Composer project for MGS Quickstart
As the library updates each layer, a custom multi-display interface driver translates these updates to update the specific display associated with the layer.
MGS Multi-zone Climate Control (binaries)
The MGS Multi-zone Climate Control application demonstrates an advanced multi-display GUI designed for vehicle or cabin climate management. The 5" LVDS display provides a touch-enabled centralized GUI, while the three SPI-based round displays can be equipped with a knob for rotary user input.
Utilizing MGS Composer, the GUI is structured so that each design layer is dedicated to a specific display within the user interface. This approach enables intuitive, zone-based control, allowing users to independently monitor and adjust climate settings for different areas of the vehicle or cabin.
Figure 3: MGS Composer project for MGS Multi-zone Climate Control