pxt-calliope/docs/reference/bluetooth/set-transmit-power.md

# Bluetooth Set Transmit Power

### ~hint
![](/static/bluetooth/Bluetooth_SIG.png)

For another device like a smartphone to use any of the Bluetooth "services" which the @boardname@ has, it must first be [paired with the @boardname@](/reference/bluetooth/bluetooth-pairing). Once paired, the other device may connect to the @boardname@ and exchange data relating to many of the @boardname@'s features.

### ~

Change the output power level of the transmitter to the given value.

```sig
bluetooth.setTransmitPower(7);
```

### Parameters

* `power`: a [number](/types/number) in the range ``0..7``, where ``0`` is the lowest power and ``7`` is the highest.

### See also

[About Bluetooth](/reference/bluetooth/about-bluetooth), [@boardname@ Bluetooth profile overview ](http://lancaster-university.github.io/microbit-docs/ble/profile/), [@boardname@ Bluetooth profile reference](http://lancaster-university.github.io/microbit-docs/resources/bluetooth/microbit-profile-V1.9-Level-2.pdf),  [Bluetooth on @boardname@ resources](http://bluetooth-mdw.blogspot.co.uk/p/bbc-microbit.html), [Bluetooth SIG](https://www.bluetooth.com)

```package
bluetooth
```