pxt-calliope/docs/reference/bluetooth/uart-write-string.md
Sam El-Husseini e3975e65e5 pxt-microbit Accessibility PR ()
* Accessibility changes
2017-09-07 13:42:08 -07:00

2.0 KiB

UART Write String

~hint

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@. Once paired, the other device may connect to the @boardname@ and exchange data relating to many of the @boardname@'s features.

~

The Bluetooth UART service allows another device such as a smartphone to exchange any data it wants to with the @boardname@, in small chunks.

With the Bluetooth UART service running, this block allows a @boardname@ to send data to a Bluetooth connected device.

bluetooth.uartWriteString("");

Example: Starting the Bluetooth UART service and then sending "HELLO" whenever button A is pressed and another device has connected over Bluetooth

let connected = 0;
bluetooth.onBluetoothConnected(() => {
    basic.showString("C");
    connected = 1;
});
bluetooth.onBluetoothDisconnected(() => {
    basic.showString("D");
    connected = 0;
});
input.onButtonPressed(Button.A, () => {
    if (connected == 1) {
        bluetooth.uartWriteString("HELLO");
    }
});

Video - UART service guessing game

https://www.youtube.com/watch?v=PgGeWddMAZ0

Advanced

For more advanced information on the @boardname@ Bluetooth UART service including information on using a smartphone, see the Lancaster University @boardname@ runtime technical documentation

See also

About Bluetooth, @boardname@ Bluetooth profile overview , @boardname@ Bluetooth profile reference, Bluetooth on @boardname@ resources, Bluetooth SIG

bluetooth