Fun with Bluetooth

A presentation at Universal JS Day in April 2018 in Ferrara, Province of Ferrara, Italy by Niels Leenheer

Slide 1

Slide 1

fun with bluetooth

Slide 2

Slide 2

why?

Slide 3

Slide 3

progressive 
 web apps

Slide 4

Slide 4

pwa’s are great !

Slide 5

Slide 5

but...

Slide 6

Slide 6

Slide 7

Slide 7

ethernet 
 & wifi

Slide 8

Slide 8

wifi

Slide 9

Slide 9

zigbee? 


Slide 10

Slide 10

ethernet

Slide 11

Slide 11

runs a webserver use fetch or 
 xmlhttprequest

Slide 12

Slide 12

[{ "id":"001788fffe100491", "internalipaddress":"192.168.2.23", "macaddress":"00:17:88:10:04:91", "name":"Philips Hue" }, { "id":"001788fffe09a168", "internalipaddress":"192.168.88.252" }, { https://www.meethue.com/api/nupnp 1

Slide 13

Slide 13

<root xmlns="urn:schemas-upnp-org:device-1-0"> <specVersion> <major>1</major> <minor>0</minor> </specVersion> <URLBase>http://192.168.2.23:80/</URLBase> <device> <deviceType>urn:schemas-upnp-org:device:Basic:1</deviceType> <friendlyName>Philips hue (192.168.2.23)</friendlyName> <manufacturer>Royal Philips Electronics</manufacturer> <manufacturerURL>http://www.philips.com</manufacturerURL> http://192.168.2.23/description.xml 2

Slide 14

Slide 14

http://192.168.2.23/api 
 {"devicetype": "hue_pwa#pixel_xl"} 3 [{"success":{"username": "........"}}] User presses physical button on the hub click save to local storage

Slide 15

Slide 15

http://192.168.2.23/api 
 {"devicetype": "hue_pwa#pixel_xl"} 3 [{"success":{"username": "........"}}] User presses physical button on the hub click save to local storage

Slide 16

Slide 16

4 { "1": { "state": { "on": true, "bri": 144, "hue": 13088, "sat": 212, "xy": [0.5128,0.4147], "ct": 467, "alert": "none", "effect": "none", http://192.168.2.23/api/......../lights

Slide 17

Slide 17

http://192.168.2.23/api/......../lights/1/state 
 { "hue": 50000, "on": true, "bri": 200 } 5 [ {"success":{"/lights/1/state/bri":200}}, {"success":{"/lights/1/state/on":true}}, {"success":{"/lights/1/state/hue":50000}} ]

Slide 18

Slide 18

clickclickreloadclick

Slide 19

Slide 19

this does 
 not work !

Slide 20

Slide 20

https only http only no certificate 
 for you

Slide 21

Slide 21

= network use remote api’s

access to local devices

Slide 22

Slide 22

hue remote api also allow control from 
 outside the local network

Slide 23

Slide 23

We are currently preparing for release of this remote API which will initially be available to a limited number of partners. “ — Philips

Slide 24

Slide 24

We are currently preparing for release of this remote API which will initially be available to a limited number of partners. “ — Philips two years ago very just nest, 
 google assistant 
 and ifttt

Slide 25

Slide 25

Slide 26

Slide 26

fun with bluetooth problems local networks

Slide 27

Slide 27

fun with bluetooth

Slide 28

Slide 28

bluetooth

Slide 29

Slide 29

bluetooth sucks

Slide 30

Slide 30

classic bluetooth the reason everybody 
 hates bluetooth bluetooth low energy vs. control drones and other cool shit

Slide 31

Slide 31

bluetooth low energy also known as BLE Bluetooth LE Bluetooth Smart Bluetooth 4

Slide 32

Slide 32

bluetooth low energy also known as BLE Bluetooth LE Bluetooth Smart Bluetooth 4 and 5

Slide 33

Slide 33

10 million


 bluetooth devices 
 shipping every day

Slide 34

Slide 34

mobile phone

Slide 35

Slide 35

computer

Slide 36

Slide 36

glucose monitor somebody's hand

Slide 37

Slide 37

activity tracker

Slide 38

Slide 38

playbulb sphere playbulb

Slide 39

Slide 39

spherio bb-8

Slide 40

Slide 40

parrot mini drone

Slide 41

Slide 41

fi dget spinner

Slide 42

Slide 42

the boring theoretical stuff

Slide 43

Slide 43

central peripheral

Slide 44

Slide 44

central

Slide 45

Slide 45

generic attribute profile

Slide 46

Slide 46

generic attribute profile ?

Slide 47

Slide 47

generic attribute profile gatt, because gap was already taken

Slide 48

Slide 48

client server

central

peripheral

Slide 49

Slide 49

§ i device information light multiple services per device

Slide 50

Slide 50

i device information battery flight control

Slide 51

Slide 51

i device information battery steering control

Slide 52

Slide 52

i device information battery heart rate

Slide 53

Slide 53

heart rate

i

device information

battery

Slide 54

Slide 54

i device information battery heart rate

Slide 55

Slide 55

i device information manufacturer
model number serial number hardware revision firmware revision software revision ... multiple characteristics 
 per service

Slide 56

Slide 56

server service characteristic value array of objects object property value

Slide 57

Slide 57

services and characteristics are identified by uuid’s 16 bit or 128 bit

Slide 58

Slide 58

0x180A 0000 180A -0000-1000-8000-00805F9B34FB 16 bit 128 bit i device information

Slide 59

Slide 59

0x180F 0000 180F -0000-1000-8000-00805F9B34FB 16 bit 128 bit battery

Slide 60

Slide 60

not recommended any UUID outside of the range 
 xxxxxxxx -0000-1000-8000-00805F9B34FB 16 bit 128 bit light steering control flight control still, everybody does this

Slide 61

Slide 61

i device information manufacturer
model number serial number hardware revision firmware revision software revision ...

Slide 62

Slide 62

i 0x180A 0x2A29
0x2A24 0x2A25 0x2A27 0x2A26 0x2A28 ... bad for readability, 
 good for saving bandwidth

Slide 63

Slide 63

read write write without response notify each characteristic supports
one or more of these

Slide 64

Slide 64

every value is an array of bytes no fancy datatypes, just bytes

Slide 65

Slide 65

pfew...

Slide 66

Slide 66

Slide 67

Slide 67

fun

with

bluetooth boring facts 
 about

Slide 68

Slide 68

fun with bluetooth

Slide 69

Slide 69

 web


 bluetooth
api still not the fun part :-(

Slide 70

Slide 70

connecting to a device

Slide 71

Slide 71

navigator.bluetooth.requestDevice({ filters: [
{ namePrefix: 'PLAYBULB' }
], optionalServices: [ 0xff0f ] }) .then(device => device.gatt.connect()) .then(server => server.getPrimaryService(0xff0f)) .then(service => service.getCharacteristic(0xfffc)) .then(characteristic => { return characteristic.writeValue( new Uint8Array([ 0x00, r, g, b ]) ); }) 1 we tell the browser what 
 kind of device we want

Slide 72

Slide 72

the user selects
the actual device

Slide 73

Slide 73

navigator.bluetooth.requestDevice({ filters: [
{ namePrefix: 'PLAYBULB' }
], optionalServices: [ 0xff0f ] }) .then(device => device.gatt.connect()) .then(server => server.getPrimaryService(0xff0f)) .then(service => service.getCharacteristic(0xfffc)) .then(characteristic => { return characteristic.writeValue( new Uint8Array([ 0x00, r, g, b ]) ); }) 2 connect to the server

Slide 74

Slide 74

navigator.bluetooth.requestDevice({ filters: [
{ namePrefix: 'PLAYBULB' }
], optionalServices: [ 0xff0f ] }) .then(device => device.gatt.connect()) .then(server => server.getPrimaryService(0xff0f)) .then(service => service.getCharacteristic(0xfffc)) .then(characteristic => { return characteristic.writeValue( new Uint8Array([ 0x00, r, g, b ]) ); }) 3 get the service

Slide 75

Slide 75

navigator.bluetooth.requestDevice({ filters: [
{ namePrefix: 'PLAYBULB' }
], optionalServices: [ 0xff0f ] }) .then(device => device.gatt.connect()) .then(server => server.getPrimaryService(0xff0f)) .then(service => service.getCharacteristic(0xfffc)) .then(characteristic => { return characteristic.writeValue( new Uint8Array([ 0x00, r, g, b ]) ); }) 4 get the characteristic

Slide 76

Slide 76

writing data

Slide 77

Slide 77

navigator.bluetooth.requestDevice({ ... }) .then(device => device.gatt.connect()) .then(server => server.getPrimaryService(0xff0f)) .then(service => service.getCharacteristic(0xfffc)) .then(c => { return c.writeValue( new Uint8Array([ 0x00, r, g, b ]) ); }) write some bytes

Slide 78

Slide 78

reading data

Slide 79

Slide 79

navigator.bluetooth.requestDevice({ ... }) .then(device => device.gatt.connect()) .then(server => server.getPrimaryService(0xff0f)) .then(service => service.getCharacteristic(0xfffc)) .then(c => c.readValue()) .then(value => { let r = value.getUint8(1);
let g = value.getUint8(2); let b = value.getUint8(3); }) read some bytes

Slide 80

Slide 80

get notified of changes

Slide 81

Slide 81

navigator.bluetooth.requestDevice({ ... }) .then(device => device.gatt.connect()) .then(server => server.getPrimaryService(0xff0f)) .then(service => service.getCharacteristic(0xfffc)) .then(c => { c.addEventListener('characteristicvaluechanged', e => { let r = e.target.value.getUint8(1);
let g = e.target.value.getUint8(2); let b = e.target.value.getUint8(3); }); c.startNotifications(); }) add event listener don't forget to start listening

Slide 82

Slide 82

things you need to know: • the webbluetooth api • promises • typed arrays duh!

Slide 83

Slide 83

browser support Chrome Opera Samsung Servo 
 (soon)

Slide 84

Slide 84

browser support Chrome Opera Samsung Servo 
 (soon) Safari

Slide 85

Slide 85

browser support Chrome Opera Samsung Servo 
 (soon) Safari

Slide 86

Slide 86

browser support Chrome Opera Samsung kinda works Servo 
 (soon) WebBLE 
 for iOS

Slide 87

Slide 87

and...

Slide 88

Slide 88

and... npm install node-web-bluetooth

Slide 89

Slide 89

and... npm install cordova-plugin-webbluetooth

Slide 90

Slide 90

and... the puck.js

Slide 91

Slide 91

custom
characteristics . wtf!

Slide 92

Slide 92

writing a value: function(r, g, b) { return new Uint8Array([ 0x00, r, g, b ]); } reading a value: function(buffer) { return { 
 r: buffer.getUint8(1), 
 g: buffer.getUint8(2), 
 b: buffer.getUint8(3) 
 } } writing to and reading 
 from the same characteristic

Slide 93

Slide 93

writing a value: function(r, g, b) { return new Uint8Array([
0x01, g, 0x01, 0x00, 0x01, 
 b, 0x01, r, 0x01, 0x00

 ]); } reading the current 
 color is not possible

Slide 94

Slide 94

writing a value: 
 function(r, g, b) { var buffer = new Uint8Array([ 
 0xaa, 0x0a, 0xfc, 0x3a, 0x86, 0x01, 0x0d, 
 0x06, 0x01, r, g, b, 0x00, 0x00, 
 (Math.random() * 1000) & 0xff, 0x55, 0x0d 
 ]); for (var i = 1; i < buffer.length - 2; i++) { buffer[15] += buffer[i]; } return buffer; } reading the current 
 color is not possible

Slide 95

Slide 95

writing a value: 
 function(r, g, b, position) { let buffer = new Uint8Array([
0x07, 0x02, position + 1, r, g, b
]); return buffer; }

Slide 96

Slide 96

writing a value: 
 function(r, g, b, position) { let buffer = new Uint8Array([
0x58, r, g, b, 0x01, position ]); ...

Slide 97

Slide 97

writing a value: 
 function(r, g, b, position) { let buffer = new Uint8Array([
0x58, r, g, b, 0x01, position ]); let payload = new Uint8Array(buffer.length + 4); payload[0] = payload.length - 2; payload[1] = payload.length - 2 >>> 8; payload.set(buffer, 2); let checksum = payload.reduce((a, b) => a + b, 0); payload[payload.length - 2] = checksum; payload[payload.length - 1] = checksum >>> 8; let extra = payload.filter(value => { 
 value === 0x01 || value === 0x02 || value == 0x03 


Slide 98

Slide 98

        message[m] = 0x03; 
        message[m + 1] = 0x05; 
        m += 2; 
    } 
    else if (payload[i] === 0x03) { 
        message[m] = 0x03; 
        message[m + 1] = 0x06; 
        m += 2; 
    } 
    else { 
        message[m] = payload[i]; 
        m++; 
    } 
} 
message[0] = 0x01; 
message[message.length - 1] = 0x02; 
return message; 

}

Slide 99

Slide 99

adafruit 
 bluetooth 
 sniffer

Slide 100

Slide 100

decompiling


 the apk don't tell anyone!

Slide 101

Slide 101

demofinally the fun part

Slide 102

Slide 102

warning experimental technology 
 setting low expectations

Slide 103

Slide 103

warning wifi interference 
 lowering them even further

Slide 104

Slide 104

#universaljsday

Slide 105

Slide 105

Slide 106

Slide 106

https://bluetooth.rocks/lightbulb 
 https://github.com/BluetoothRocks/Lightbulb change the colour 
 of a lightbulb

Slide 107

Slide 107

https://bluetooth.rocks/pixel 
 https://github.com/BluetoothRocks/Matrix draw pixel art on 
 a led matrix display

Slide 108

Slide 108

https://bluetooth.rocks/racer https://github.com/BluetoothRocks/Racer control a lego racer 
 using a gamepad use css animations to 
 define a path

Slide 109

Slide 109

https://bluetooth.rocks/drone 
 https://github.com/BluetoothRocks/Drone control a drone 
 from your browser

Slide 110

Slide 110

https://bluetooth.rocks/printer 
 https://github.com/BluetoothRocks/TweetPrinter print on a receipt printer

Slide 111

Slide 111

https://bluetooth.rocks/pulse 
 https://github.com/BluetoothRocks/Pulsefind out your 
 current heartbeat

Slide 112

Slide 112

fun with bluetooth !

Slide 113

Slide 113

questions? @html5test