Reach offers two display module product lines.
Compare by Device Type
“Generation One” products have been in production 10+ years. They use a UART-style interface to the host processor and RS232 or CMOS levels, and run a bare-metal code loop with a fixed set of commands and support macros (user-defined sequences of standard commands). These SLCD series display modules act as a smart slave device to the host processor. The host processor sends a command to the screen, and the display returns a reply. Press a button, or move a slider and the display sends a message to the host processor. ReachTech.com
The advanced “Generation Two” products use a more powerful processor and run embedded Linux and powered by either a G2C1 or G2H2 controller. The GUI application is user defined using Qt Creator and the QML language. The GUI application runs on the display module and interacts with the host processor on a data sharing model. ASCII strings pass from the host processor to the display module to update items on the screen. ASCII strings move from the display to the host processor when the user touches the screen (button, slider, etc.). The display module supports UART-style interfaces with RS232, RS485, or CMOS, plus they have other interfaces such as Ethernet, USB, and CAN. They also support I2C and 8-bit GPIO pins. Advanced Display Modules at LinuxTouch.com
Compare Development Paths
Screen images are typically bitmaps, with some additional graphical elements (lines, circles, etc.) drawn using standard commands. Applications may consist of a general background bitmap with other bitmaps layered for buttons, menu-specific decorations, meters, sliders, etc. The bitmaps are all stored in Flash on the display module and referenced by a number. Drawing a bitmap is done with a simple ASCII command such as “xi 1 0 0”, which draws bitmap 1 at X/Y coordinates 0/0. A command such as ‘bdc 10 100 100 1 “Start” 10 11’ defines a button. This coding creates a button numbered 10, located at X/Y 100/100, with an action type of ‘1’ (momentary contact), using the text “Start” for the label, and using bitmaps 10 and 11 for the unpressed and pressed states. Placement of bitmaps on the screen can be a manual process, or GIMP scripts are available to assist with the layout. How It Works
Develop a GUI with Qt Creator. Reach provides several design elements for items (buttons, sliders, meters, level bars, etc.) which the user can drag-and-drop onto the screen-sized canvas, where they may be resized and aligned as appropriate. After doing the GUI layout, go to ‘code view’ and add simple code to the items created to interact with your host processor. Advanced Interface Development Tools
|Interface (I/O options)||
|Device Type||Smart Slave to Host Processor: Host processor sends commands to display. Display returns reply.||Smart Slave to Host Processor: uses a data sharing model with ASCII Strings passed from display to host. A translate layer insulates core functions from GUI changes.|
|GUI Development||Standard Commands, BMPs stored in Flash, manual placement or use of GIMP scripts for layout.||
|Display Sizes||4.3”, 5.7″, 7”, 8.4”, 12.1”||4.3”, 5.7”, 7”, 10.1”|
|Touch Type||Resistive, some Projected Capacitive options.||Both Resistive and Projected Capacitive options in most modules.|
|Processor||16/32 bit CISC or 266MHz ARM||i.MX28 or i.MX 6Solo|
|Price||$1692 (4.3” Model: SLCD43R)||$1762 (4.3” Model: G2C1L-R)|
|Family||Generation One||Generation Two|
|In Production Since||10+ years||3+ years|
1 Some modules.
2 Annual production volume of 100 units.