TRM-425 Four-line by 20-character Serial LCD with Keypad Input, 95-screen Memory
TRM-425s are text LCDs with an advanced serial interface factory-installed. The LCD displays text received serially, and the interface understands common terminal-style formatting instructions (e.g., carriage return, tab, etc.) The TRM-425 can interface a keypad of up to 16 buttons and transmit configurable keycodes serially. In addition, it has a large EEPROM memory that can store up to 95 predefined screens of data for instant recall.
TRM-425 Features
- Compact, high-contrast 4x20 LCD
- 1200-9600bps serial input with 64-byte buffer
- Interface matrix keypads up to 16 keys
- EEPROM holds 95 text screens plus custom characters and configuration
- Temperature compensation for consistent contrast
- Compatible with all BPP-series features
- Faceplate and mounting hardware included
- Deep inventory for no-lead-time delivery
Basic Specifications
| Power Requirements |
4.8 to 5.5Vdc at 10mA (60mA backlight on) |
| User Connector |
8-pin header, 0.025in. posts on 0.10in. centers |
| Serial Input |
RS-232, inverted or noninverted TTL, 1200-9600bps |
| Operating Temperature |
0° to 50° C, contrast compensated |
| LCD Type |
Supertwist (STN) yellow-green |
| Optimum View Direction |
6 o'clock |
Dimensions (in mm)
Total depth (front of screen to highest point on pcb) is 28mm.
| A |
y offset edge to hole center (top & bottom) |
3.50 |
| B |
y pcb height |
47.00 |
| C |
y hole spacing |
40.00 |
| D |
y screen opening |
22.20 |
| E |
y character height (small font) |
4.00 |
| F |
x character width (small font) |
2.30 |
| G |
x offset pcb edge to hole center (bottom) |
3.50 |
| H |
x screen frame |
76.20 |
| I |
x screen opening |
60.00 |
| J |
x hole spacing (bottom) |
70.00 |
| K |
x pcb width |
77.00 |
| L |
y frame height |
32.60 |
| - |
mounting hole diameter |
3.50 |
| - |
screen frame depth |
9.50 |
LCD Instructions
The TRM-425 works like a mini-terminal, displaying text and responding to traditional control characters like linefeeds, carriage returns, tabs, etc. In addition to the standard text features of the BPP- series, the TRM also offers a keypad input (up to 16 keys in a 4-row by 4-column matrix connection) and EEPROM memory storage for up to 95 text screens plus configuration data.
| LCD Instruction (ctrl code) |
ASCII |
Hex |
| Null; ignored but may be used for timing (ctrl-@) |
0 |
0x00 |
| Home cursor (ctrl-A) |
1 |
0x01 |
| Begin inverse (light-on-dark) text (ctrl-B) |
2 |
0x02 |
| End inverse text (ctrl-C) |
3 |
0x03 |
| Ignored (ctrl-D thru G) |
4-7 |
0x04-0x07 |
| Backspace (ctrl-H) |
8 |
0x08 |
| Tab: jump to next multiple-of-4 column (ctrl-I) |
9 |
0x09 |
| Smart linefeed: move down one row (ctrl-J) |
10 |
0x0A |
| Vertical tab: move up one row (ctrl-K) |
11 |
0x0B |
| Formfeed: clear the screen (ctrl-L) |
12 |
0x0C |
| Carriage return: move to beginning of next line (ctrl-M) |
13 |
0x0D |
| Turn backlight on (ctrl-N) |
14 |
0x0E |
| Turn backlight off (ctrl-O) |
15 |
0x0F |
| Accept cursor-position data (next byte) (ctrl-P) |
16 |
0x10 |
| Ignored (ctrl-Q) |
17 |
0x11 |
| Accept right-alignment data (ctrl-R) |
18 |
0x12 |
| Ignored |
19-26 |
0x13-0x1A |
| Escape character: begin multipart instruction* |
27 |
0x1B |
| *See below. |
Escape Sequences
| Escape Sequence |
Function |
| ESC D n B0-B7 |
Define custom character n according to byte B0-B7 |
| ESC E n |
Recall (display) EEPROM stored screen n (0 to 94) |
| ESC e n {data} |
Recall EEPROM stored custom character set n (0-7) |
| ESC X n |
Store current screen to EEPROM page n (0-94) |
| ESC x n |
Store current custom character set to EEPROM page n (0-7) |
| ESC W B0-B31 |
Store configuration data bytes B0-B31 |
Accessories
- TRM-CBL DB9 serial cable for configuration
TRM-425L includes a mounting kit at no extra charge.
