LCD
Shows text on a 16x2 (or 20x4) HD44780 character LCD — through an I2C backpack (the common "I2C LCD" module, 4 pins), or wired straight to the board in 4-bit parallel mode (6 pins) when there's no I2C.
Shows text on a 16x2 (or 20x4) HD44780 character LCD — through an I2C backpack (the common "I2C LCD" module, 4 pins), or wired straight to the board in 4-bit parallel mode (6 pins) when there's no I2C. Print writes text or a bound value on a line, Clear blanks it, Backlight turns the light on or off. Every action on the same wiring drives the same display.
| Node | Kind | What it does |
|---|---|---|
| Action | Writes text — or a bound value, like a sensor's reading — on a line of the display. | |
| Clear | Action | Blanks the whole display, or one line of it. |
| Backlight | Action | Turns the backlight on or off — what's on the display stays. |
Actions
Writes text — or a bound value, like a sensor's reading — on a line of the display.
Settings
| Setting | Type | Default | What it's for |
|---|---|---|---|
| Connection | One of: I2C backpack, Parallel (4-bit) | I2C backpack | How the display is wired — an I2C backpack (4 pins), or straight to the board (6 pins, no I2C needed). |
| SDA Pin | Pin (digital out) | GPIO21 | Shown when Connection is I2C backpack. Board pin wired to the backpack's SDA. |
| SCL Pin | Pin (digital out) | GPIO22 | Shown when Connection is I2C backpack. Board pin wired to the backpack's SCL. |
| RS Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's RS (pin 4). |
| E Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's E (pin 6). RW (pin 5) goes to GND. |
| D4 Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's D4 (pin 11). |
| D5 Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's D5 (pin 12). |
| D6 Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's D6 (pin 13). |
| D7 Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's D7 (pin 14). |
| Text | Text | Hello, world! | What to show — type it, or bind an output or a variable (numbers are formatted, see Decimals). A typed \n goes on to the next line. Accents show as their plain letter (no glyphs for them on the LCD). |
| Line | One of: Line 1, Line 2, Line 3, Line 4 | Line 1 | Which line to write on (3 and 4 only on a 20x4). |
| Align | One of: Left, Center, Right | Left | Where on the line the text goes. |
| Format | Text | — | Advanced. Text around Text — {} stands for it: "Temp: {} °C". Without {}, it goes before it. |
| Column | Number | 1 | Advanced. Shown when Align is Left. Which column the text starts at, from 1. |
| Clear Line | On / off | On | Advanced. Blank the rest of the line, so a shorter text doesn't leave the end of the last one behind. |
| Decimals | Number | 2 | Advanced. Decimal places of a bound number that isn't whole (0–6). |
| Address | Text | 0x27 | Advanced. Shown when Connection is I2C backpack. The backpack's I2C address — 0x27 on most, 0x3F on some (PCF8574A). |
| Size | One of: 16x2, 20x4 | 16x2 | Advanced. The display's size, in characters. |
Clear
Blanks the whole display, or one line of it.
Settings
| Setting | Type | Default | What it's for |
|---|---|---|---|
| Connection | One of: I2C backpack, Parallel (4-bit) | I2C backpack | How the display is wired — an I2C backpack (4 pins), or straight to the board (6 pins, no I2C needed). |
| SDA Pin | Pin (digital out) | GPIO21 | Shown when Connection is I2C backpack. Board pin wired to the backpack's SDA. |
| SCL Pin | Pin (digital out) | GPIO22 | Shown when Connection is I2C backpack. Board pin wired to the backpack's SCL. |
| RS Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's RS (pin 4). |
| E Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's E (pin 6). RW (pin 5) goes to GND. |
| D4 Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's D4 (pin 11). |
| D5 Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's D5 (pin 12). |
| D6 Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's D6 (pin 13). |
| D7 Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin wired to the display's D7 (pin 14). |
| Line | One of: Whole display, Line 1, Line 2, Line 3, Line 4 | Whole display | What to blank. |
| Address | Text | 0x27 | Advanced. Shown when Connection is I2C backpack. The backpack's I2C address — 0x27 on most, 0x3F on some (PCF8574A). |
| Size | One of: 16x2, 20x4 | 16x2 | Advanced. The display's size, in characters. |
Backlight
Turns the backlight on or off — what's on the display stays. On I2C the backpack switches it; in parallel, the board drives Backlight Pin.
Settings
| Setting | Type | Default | What it's for |
|---|---|---|---|
| Connection | One of: I2C backpack, Parallel (4-bit) | I2C backpack | How the display is wired — an I2C backpack (4 pins), or straight to the board (6 pins, no I2C needed). |
| SDA Pin | Pin (digital out) | GPIO21 | Shown when Connection is I2C backpack. Board pin wired to the backpack's SDA. |
| SCL Pin | Pin (digital out) | GPIO22 | Shown when Connection is I2C backpack. Board pin wired to the backpack's SCL. |
| Backlight Pin | Pin (digital out) | — | Shown when Connection is Parallel (4-bit). Board pin driving the display's backlight (A, pin 15 — through a resistor, or a transistor for brighter modules). Parallel only. |
| On | On / off | On | Light on (or off). |
| Address | Text | 0x27 | Advanced. Shown when Connection is I2C backpack. The backpack's I2C address — 0x27 on most, 0x3F on some (PCF8574A). |
| Size | One of: 16x2, 20x4 | 16x2 | Advanced. The display's size, in characters. |