This is a slide talking about nodeboat workshop at JSConf Asia 2014. If you are interested in controlling hardware via javascript, then spark.io is truely a great idea for you to try.

1. Jesse Chen
Build a boat with node.js
and spark.io
JSConf Asia 2014 Workshop

2. Schema
• How node boat works?
• Building the boat
• Competition
• Afterward

3. How node boat works?

4. Node.js
+
spark core

5. Spark core
app
controller
Authorize
Authorize
command
command
command

6. During workshop
honestly

8. I will do my best to explain
anyway

9. Setup your Spark core

13. - Register at spark.io
- Install spark-cli
- Pair up spark core with your spark.io account
- Try using cli to control the LED (which is D7 pin)
on spark core
Step by step
$ spark setup
$ npm install -g spark-cli
$ spark call {SPARK_CORE_NAME} digitalwrite D7,HIGH

14. - Try request to spark cloud api with http methods
Remote access
GET : respond all available methods
POST : send command
$ curl -X POST -H "Authorization: Bearer {ACCESS_TOKEN}" https://
api.spark.io/v1/devices/{DEVICE_ID}/digitalwrite -d
params=D7,HIGH
$ curl -X GET -H "Authorization: Bearer {ACCESS_TOKEN}" https://
api.spark.io/v1/devices/{DEVICE_ID}

15. - Reasons to use TCP
- faster
- faster, almost realtime
- Load voodoospark firmware
Use TCP instead
$ spark flash {DEVICE_ID} voodoo

16. Spark core
app
controller
Authorize
command command
Authorize

17. - Require npm modules
- spark-io
- johnny-five
- Try to control D7 pin
node.js app
var five = require("johnny-five");
var Spark = require("spark-io");
var board = new five.Board({
io: new Spark({
token: process.env.SPARK_TOKEN,
deviceId: process.env.SPARK_DEVICE_ID
})
});
board.on("ready", function() {
var led = new five.Led("D7");
// This js injects the led variable into the
// repl you get afterscript finishes execution.
board.repl.inject({
led: led
});
});
>> led.on()
>> led.off()

18. Time to get hands dirty

19. Motor 1 - A0 pin
Motor 2 - A1 pin
Servo - A7 pin

21. Propeller

24. Boat

25. - Buoyancy
- Control direction
Two important things

26. Buoyancy
NO leak Balance

28. Direction
Rudder
other choice?

31. Our boat is READY
finally

33. One more thing
is missing

35. - express.js web server
Nodejs app
// start
app.get('/start', function (req,
res) {
power = 255;
if (motorR) {
motorR.start(power);
}
if (motorL) {
motorL.start(power)
}
return
res.status(200).send('start');
})
// 80 is center for us // plus degree, max 130
app.get('/left', function (req, res) {
var v;
if (d < 80) {
d = 80;
}
d += 10;
console.log('turn left: ', d);
if (d > 130) {
d = 130;
console.log(d);
return res.status(200).send('maxium 130
degree matched');
}
if (servo) {
v = servo.to(d);
return res.status(200).send(d.toString());
}
})

36. - XMLHttpRequest ajax
Web app
// start
$('#start').click(function () {
defer = $.get('/start', function () {
$('#status').text('Boat started! Speed at 255');
});
});

37. - Rudder didn’t work well
- Motor output from 100 -> 255!
Trial run

38. - speed 33%
- controller design 33%
- boat design 33%
Competition time

44. - socket.io
- steering as the same concept of TANK
Optimisation

45. - https://www.spark.io/
- https://github.com/notthetup/nodeboatbuilder/
blob/master/getting-started.md
Thank you