pxt-calliope/docs/reference/pins/i2c-write-number.md

# i2c Write Number

Write a number to a device at an I2C address using a specified number format.

```sig
pins.i2cWriteNumber(0, 0, NumberFormat.Int8LE, true);
```

### ~hint

**Simulator**

This function needs real hardware to work with. It's not supported in the simulator.

### ~

## Parameters

* **address**: the 7-bit I2C address of the device to send to send **value** to.
* **value**: the number to send to **address**.
* **format**: the [NumberFormat](/types/buffer/number-format) for **value**.
* **repeated**: if `true`, don't send a stop condition after the write. Otherwise, a stop condition is sent when `false` (the default).

### ~ hint

A [repeated start condition](http://www.i2c-bus.org/repeated-start-condition/) is set to help make sure that when you want to write multiple numbers from the device at one time, it can happen without interruption. A start conditon is sent (if **repeated** is `true`) each time a number is written without a matching stop condition. When the last number is written, the stop conditon can be sent by setting **repeated** to `false`. For single writes, don't use **repeated** or set it to `false`.

### ~

## Examples

### Write a big endian number to a device

Send the value `2055` to the 7-bit I2C address as a 32-bit number. The `32`, big-endian, and integer chosen for the format.

```blocks
pins.i2cWriteNumber(32, 2055, NumberFormat.Int32BE, false);
```

### Reapeted writes

Send three byte values to a device at address `33`.

```blocks
pins.i2cWriteNumber(33, 19, NumberFormat.Int32BE, true);
pins.i2cWriteNumber(33, 61, NumberFormat.Int32BE, true);
pins.i2cWriteNumber(33, 87, NumberFormat.Int32BE, false);
```

## See also

[i2c read number](/reference/pins/i2c-read-number)

[What's I2C?](http://www.i2c-bus.org/), [number format](/types/buffer/number-format)