The DFRobot FIT0127 is a family of HD44780-compatible character LCD modules commonly used in embedded systems and hobbyist projects. These displays provide alphanumeric output using a dot-matrix character generator and support both 8-bit and 4-bit parallel interfaces.
FIT0127 modules are frequently paired with microcontrollers and 8-bit CPUs such as the 6502, AVR, PIC, and Arduino platforms.
| Feature | Description |
|---|
| Display type | Character LCD (STN, Yellow-Green backlight typical) |
| Controller | HD44780 or compatible |
| Interface | Parallel (4-bit or 8-bit) |
| Character size | 5 x 8 dot matrix |
| Operating voltage | 5 V logic (some variants support 3.3 V) |
| Backlight | LED (separate power pins) |
| Viewing mode | Transflective |
The FIT0127 designation is commonly associated with 16x2 character LCD modules.
| Variant | Characters |
|---|
| FIT0127 | 16 columns x 2 rows |
| Pin | Name | Description |
|---|
| 1 | VSS | Ground |
| 2 | VDD | +5 V supply |
| 3 | VO | Contrast adjust |
| 4 | RS | Register Select |
| 5 | R/W | Read/Write select |
| 6 | E | Enable |
| 7 | D0 | Data bit 0 |
| 8 | D1 | Data bit 1 |
| 9 | D2 | Data bit 2 |
| 10 | D3 | Data bit 3 |
| 11 | D4 | Data bit 4 |
| 12 | D5 | Data bit 5 |
| 13 | D6 | Data bit 6 |
| 14 | D7 | Data bit 7 |
| 15 | A | Backlight Anode (+) |
| 16 | K | Backlight Cathode (-) |
| Parameter | Value |
|---|
| Logic voltage (VDD) | 4.5 - 5.5 V |
| Logic current | ~1-2 mA |
| Backlight voltage | ~4.2 V |
| Backlight current | 15-30 mA |
| RS | Function |
|---|
| 0 | Instruction register |
| 1 | Data register |
| R/W | Operation |
|---|
| 0 | Write to LCD |
| 1 | Read from LCD |
- Data is latched on the falling edge of E
- E must be pulsed HIGH LOW for each transfer
- Uses D0-D7
- Faster operation
- Uses D4-D7 only
- Data transferred in two nibbles (high first)
- Saves I/O pins
| Address | Display Position |
|---|
| 0x00-0x0F | Line 1, Col 1-16 |
| 0x40-0x4F | Line 2, Col 1-16 |
- Supports up to 8 custom characters
- Each character uses 8 bytes
| Instruction | Description |
|---|
| 0x01 | Clear display |
| 0x02 | Return home |
| 0x04-0x07 | Entry mode set |
| 0x08-0x0F | Display on/off control |
| 0x10-0x1F | Cursor/display shift |
| 0x20-0x3F | Function set |
| 0x40-0x7F | Set CGRAM address |
| 0x80-0xFF | Set DDRAM address |
Wait >15 ms after VDD rises
Function set: 0x33
Function set: 0x32
Function set: 0x28 (4-bit, 2-line)
Display ON/OFF: 0x0C
Entry mode: 0x06
Clear display: 0x01
| Operation | Time |
|---|
| Enable pulse width | ≥ 450 ns |
| Command execution | ~37 µs |
| Clear / Home | ~1.52 ms |
RS VIA output
E VIA output
D4-D7 VIA Port B
R/W Grounded (write-only)
- Contrast adjusted via potentiometer on VO pin
- Backlight may require series resistor
- PWM dimming supported via external control
| Parameter | Rating |
|---|
| VDD | -0.3 V to +6.0 V |
| Input voltage | -0.3 V to VDD + 0.3 V |
| Operating temp | -20 °C to +70 °C |
- Status displays
- Debug output for SBCs
- User interfaces for embedded systems
- Retrocomputer front panels