---
title: chardisplay
slug: develop/chardisplay
docTags: 
createdAt: 2025-03-11T07:07:19.526Z
---

The *chardisplay* object lets you set the properties of characters on a display. It is available in BOS 9.0.203 and later, and BOS 9.1.29 and later.

**chardisplay IDL**

```text
interface CharDisplay {
    Promise<void> show(in unsigned long row, in unsigned long col, in DOMString text)
    Promise<void> clear()
    Promise<void> setPos(in unsigned long row, in unsigned long col)
    Promise<void> setCursor(in unsigned long cursor) // 0=off, 1=blink, 2=underline, 3=both
    Promise<void> setContrast(in unsigned long contrast) // 0-100
    Promise<int> getContrast()
    Promise<void> setBrightness(in unsigned long brightness) // 0-100
    Promise<int> getBrightness()
    Promise<int> getColumns()
    Promise<int> getRows()
}
```

## Object Creation

To create a *chardisplay* object, load the *@brightsign/chardisplay* module using the Node.js® require() method:

```javascript
var chardisplayClass = require("@brightsign/chardisplay");
var chardisplay = new chardisplayClass();
```

## CharDisplay

### show()

```javascript
Promise<void> show(in unsigned long row, in unsigned long col, in DOMString text)
```

Displays text at a prescribed position

### clear()

```javascript
Promise<void> clear()
```

Clears the display

### setPos()

```javascript
Promise<void> setPos(in unsigned long row, in unsigned long col)
```

Positions the cursor

### setCursor()

```javascript
Promise<void> setCursor(in unsigned long cursor)
```

Sets the cursor style:&#x20;

- 0 is off
- 1 is blink
- 2 is underline
- 3 is both

### setContrast()

```javascript
Promise<void> setContrast(in unsigned long contrast)
```

Set the display contrast in values from 0 to 100

### getContrast()

```javascript
Promise<void> getContrast()
```

Gets the display contrast

### setBrightness()

```javascript
Promise<void> setBrightness(in unsigned long brightness)
```

Set the display brightness in values from 0 to 100

### getBrightness()

```javascript
Promise<int> getBrightness()
```

Gets the display brightness

### getColumns()

```javascript
Promise<int> getColumns()
```

Returns the number of columns. This is useful for writing code that loops over the available rows and columns. 

### getRows()

```javascript
Promise<int> getRows()
```

Returns the number of rows. This is useful for writing code that loops over the available rows and columns.