Include technologies covered - Node.js | ORDS | Spatial Have you ever wanted to track the location of a physical object and trigger an action based on the proximity of that object? The problem is, how to do this without spending a small fortune? In this session, Blaine walks through using Raspberry Pi to track a small Bluetooth LE beacon. After a short explanation of BLE beacons, he talks about configuring the Pi and adding the software. Beacon tracking generates lots of data for analysis which needs a home, ie, a database. Using REST APIs, Blaine safely stores the data in a cloud database and demonstrates using spatial queries to find the location of the beacon. Attendees will come away from this session with the tools to build their own beacon scanning system that won't break the bank.

1. Howdy, I’m Blaine Carter
Oracle Corpora on
Developer Advocate for Open Source
Email: blaine.carter@oracle.com
Blog: learncodeshare.net
Twi er: @OraBlaineOS
YouTube: www.youtube.com/blainecarter
Team: community.oracle.com/docs/DOC-917690

2. Beacon Tracking on a Budget

3. Bluetooth Low Energy Beacon
Typical broadcast data:
Major: 4
Minor: 6597
UUID: 6b12c4274890
RSSI: -81
TX: -59

4. Calculate the distance to the beacon using tx and rssi
h ps://stackoverflow.com/a/20434019/1296150
function calculateDistance(uuid, rssi) {
var txPower = -59;
var distance;
if (rssi === 0) {
return -1.0;
}
var ratio = rssi * 1.0 / txPower;
if (ratio < 1.0) {
distance = Math.pow(ratio, 10);
} else {
distance = (0.89976) * Math.pow(ratio, 7.7095) + 0.111;
}
Rolling Average
var distanceQueues = {}; //Stored outside of the function
if (distanceQueues.hasOwnProperty(uuid) === false) {
distanceQueues[uuid] = (Array.apply(null, Array(5)))
.map(function() {return distance;});
} else {
distanceQueues[uuid].push(distance);
distanceQueues[uuid].shift();
}
{
"0d60a289203": [2.3, 2.5, 2.1, 2.4, 2.4],
"5a364a32456c": [1.7, 2.5, 1.6, 1.8, 1.4]
}

5. Weighted Average
NormalAverage:
WeightedAverage:
...
var sum = 0;
var weight = 0;
for (var i = 0; i < distanceQueues[uuid].length; i++) {
sum += (i + 1) * distanceQueues[uuid][i];
weight += i + 1;
}
var avg = sum / weight;
return avg;
}
= 3.4
(3 + 4 + 3 + 5 + 2)
5
= 3.3
((0 + 1) ∗ 3 + (1 + 1) ∗ 4 + (1 + 2) ∗ 3 + (1 + 3) ∗ 5 + (1 + 4) ∗ 2)
((0 + 1) + (1 + 1) + (1 + 2) + (1 + 3) + (1 + 4))
Install Raspbian using Etcher

6. Enable SSH
touch /boot/ssh
Authorize an RSA Key

7. Add your key to ~/.ssh/authorized_keys
install -d -m 700 /rootfs/home/pi/.ssh
cat ~/.ssh/id_rsa.pub >> /rootfs/home/pi/.ssh/authorized_keys
Setup WIFI
Edit /roo s/etc/wpa_supplicant/wpa_supplicant.conf
network={
ssid="Your SSID"
psk="YourWPAPassword"
key_mgmt=WPA-PSK
}

8. Update Raspbian
1. Put the SD card in your Raspberry Pi
2. Boot it up
3. SSH to pi
4. Change password (default password: raspberry)
5. Run an update
ssh pi@192.168.0.2
passwd
sudo apt-get update
Install Bluetooth Libraries
sudo apt-get install -y bluetooth bluez libbluetooth-dev libudev-dev

9. Install Node.js
Remove pre-installed Node (if any)
Node Version Manager
sudo apt-get remove --purge npm node nodejs
curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh | bash
source .bashrc
nvm install node
node -v
npm -v
Allow Node to access bluetooth
sudo setcap cap_net_raw+eip $(eval readlink -f `which node`)

10. Setup Environment Variables
SCANNER_ID – The ID for this scanner.
BEACON_UUID – UUID of the beacon you’re tracking.
IFTTT_KEY – your account key for IFTTT
ORDS_URI – http://example.com/ords/beacon/beacon/alert/
Scan For a Beacon
var bu = require('./beaconUtil.js');
var bleacon = require('bleacon');
var beaconId = process.env.BEACON_UUID;

11. bleacon.startScanning(beaconId);
bleacon.on('discover', function(bleacon) {
var uuid = bleacon.uuid,
major = bleacon.major,
minor = bleacon.minor,
rssi = bleacon.rssi,
accuracy = bleacon.accuracy.toFixed(2),
proximity = bleacon.proximity,
distance = 0;
distance = bu.calculateDistance(uuid, rssi).toFixed(2);
console.log("UUID: " + uuid + "nMajor:" + major + "nMinor:" + minor +
"nrssi:" + bleacon.rssi + "naccuracy:" + accuracy +
"nProximity:" + proximity + "nDistance:" + distance + "nn");
});
Trigger an Ac on
var bu = require('./beaconUtil.js');
var bleacon = require('bleacon');
var beaconId = process.env.BEACON_UUID;
var scannerID = process.env.SCANNER_ID;
bleacon.startScanning(process.env.BEACON_UUID);
bleacon.on('discover', function(bleacon) {
var uuid = bleacon.uuid,
major = bleacon.major,
minor = bleacon.minor,
rssi = bleacon.rssi,
accuracy = bleacon.accuracy.toFixed(2),
proximity = bleacon.proximity,
distance = 0;
distance = bu.calculateDistance(bleacon.uuid, bleacon.rssi).toFixed(2);
//Process the alert action
if (distance < 2) {
bu.iftttNotify('LeftRoom', scannerID, beaconId, distance);
}
});

12. Home Automa on
Messages - IFTTT (If This Then That) - h ps://i .com
Home Assistant - h ps://home-assistant.io
Deadbolt
Sonos
Oracle REST Data Services
begin
ords.enable_schema(
p_enabled => true,
p_schema => 'BEACON',
p_url_mapping_type => 'BASE_PATH',
p_url_mapping_pattern => 'beacon',
p_auto_rest_auth => false);
ords.define_module(
p_module_name => 'Beacon',
p_base_path => '/beacon/',
p_items_per_page => 25,
p_status => 'PUBLISHED');
ords.define_template(
p_module_name => 'Beacon',
p_pattern => 'scan',
p_priority => 0,
p_etag_type => 'HASH',
p_etag_query => null);
ords.define_handler(
p_module_name => 'Beacon',
p_pattern => 'scan',
p_method => 'GET',
p_source_type => 'json/query',
p_items_per_page => 25,

13. p_mimes_allowed => '',
p_source => 'select *
from reading
order by created_on');
commit;
end;
Consume Rest API
var bu = require('./beaconUtil.js');
var bleacon = require('bleacon');
var beaconId = process.env.BEACON_UUID;
var scannerID = process.env.SCANNER_ID;
var request = require('request');
var ordsUri = process.env.ORDS_URI;
//get the alerts for this scanner
var alerts = [];
request.get({
url: ordsUri + 'alert/' + scannerID,
json: true
}, function(err, res, body) {
if (err) {
console.log(err);
}
alerts = body;
bleacon.startScanning(process.env.BEACON_UUID);
console.log('Scanning:', alerts);
});
bleacon.on('discover', function(bleacon) {
var uuid = bleacon.uuid,
major = bleacon.major,
minor = bleacon.minor,
i bl i
My beaconScan Repository
h ps://github.com/bcarter/beaconScan

14. There's more we could do
What if you want to map the beacon loca on?
Table Data
scanner_id beacon_id distance created_on
5 myBeacon 4.72 27-AUG-1704.19.58.082247PM
7 myBeacon 6.57 27-AUG-1704.19.58.780495PM

15. 6 myBeacon 4.64 27-AUG-1704.19.58.780855PM
7 myBeacon 5.84 27-AUG-1704.19.59.270639PM
6 myBeacon 4.8 27-AUG-1704.19.59.279716PM
5 myBeacon 4.8 27-AUG-1704.19.59.489140PM
7 myBeacon 6.65 27-AUG-1704.19.59.538878PM
5 myBeacon 5.36 27-AUG-1704.20.00.187193PM
6 myBeacon 4.71 27-AUG-1704.20.00.239919PM
6 myBeacon 3.95 27-AUG-1704.20.00.240297PM
7 myBeacon 6.41 27-AUG-1704.20.00.908366PM
5 myBeacon 5.12 27-AUG-1704.20.00.949043PM
6 myBeacon 4.21 27-AUG-1704.20.01.072711PM
7 myBeacon 5.92 27-AUG-1704.20.01.630422PM
7 myBeacon 6.85 27-AUG-1704.20.01.667588PM
6 myBeacon 4.69 27-AUG-1704.20.02.347791PM
5 myBeacon 5.5 27-AUG-1704.20.02.348201PM
7 myBeacon 5.88 27-AUG-1704.20.02.349190PM
Round to the nearest X
Round mestamps to the nearest 5 seconds
1. (cast(created_on as date) - date '1970-01-01')
2. *24*60*60
3. round((...)/5)
4. * 5
h ps://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:13946369553642
select round(((cast(created_on as date) - date '1970-01-01')
*24*60*60)
/5)
* 5
from reading
order by 2;

16. Trilatera on
(d,0)
(0,0)
(i,j)
r1
d
r2
P2P1
P3
r3
i
j
Intersections
x positive
right
y positive
down
Scanning with Raspberry Pi

17. Raspberry Pi Zero W
Raspberry Pi Zero W

18. Raspberry Pi 3

19. Oracle Spa al
sdo_geometry OBJECT (SDO_GTYPE NUMBER,
SDO_SRID NUMBER,
SDO_POINT SDO_POINT_TYPE,
SDO_ELEM_INFO SDO_ELEM_INFO_ARRAY,
SDO_ORDINATES SDO_ORDINATE_ARRAY);
sdo_geometry(2003,
null,
null,
mdsys.sdo_elem_info_array(1, 1003, 3),
mdsys.sdo_ordinate_array(x,y,
x,y))

20. Draw a circle using x, y, radius
Convert x, y + radius into 3 points on the circle
mdsys.sdo_geometry(
2003,
null,
null,
mdsys.sdo_elem_info_array(1, 1003, 4),
mdsys.sdo_ordinate_array(
(x - rad), y,
x, (y + rad),
(x + rad), y
));
Intersec ng Polygons

21. SDO_GEOM.SDO_INTERSECTION(sdo_geometry(2003, null, null,
mdsys.sdo_elem_info_array(1, 1003, 3),
mdsys.sdo_ordinate_array(0,0, 10,10)),
beacon_tools.circle(0, 0, 5),
0.005)
Beacon Enters a Pre-Defined Zone
Define zones using polygons.
select zone
from restricted_areas
where SDO_OVERLAPBDYINTERSECT(zone,
beacon_tools.location('beacon1','someTimestamp'));
Recap