Introduction to open-source Arduino hardware and software for environmental/geographical applications

1. First-year Physical Geography Taster Sessions
Dr Thomas Smith
INTELLIGENT TWEETING SENSORS:
INTRODUCING ARDUINO MICROCONTROLLERS

3. THE BASICS OF ARDUINO MICROCONTROLLERS
• Open source hardware
• Open source development kit
• User community driven

4. WHAT DO THEY DO?
• Digital I/O (LEDs, switches)
• Analogue I/O (resistive sensor data)
• Serial connection (sensors, GPS, etc.)
• Programmable from your PC/Mac/Linux
• Your limit is only your creativity!!

5. TERMINOLOGY
• I/O Board – main microcontroller
• Shield – add-on boards
• Sketch – the program
• Sensor – components (thermistors, etc.)
• Modules – serial data (GPS module, etc.)

6. 14 current boards
ARDUINO I/O BOARDS

7. SHIELDS

8. SHIELDS
Touchscreen Shield
Wave Shield
Datalogging Shield

9. COMMUNICATION SHIELDS
Ethernet Shield GSM Shield Wifi Shield

10. Gas Sensor Temp & Humidity
Flex Sensor
Fingerprint Scanner
Geiger Counter
SENSORS

11. Photo/thermistor, infared, force sensitive resistor, Hall effect,
Piezo, tilt sensor..
SENSORS

12. SKETCHES
Includes
Globals
void setup()
void loop()

13. HANDLING THE ARDUINO – HOW NOT TO DO IT!
Improper Handling - NEVER!!!

14. HANDLING THE ARDUINO – THE PROPER WAY
Proper Handling - by the edges!!!

15. TRY IT OUT 1: VERY SIMPLE LED BLINKING PROGRAM
int ledpin = 13;
int del = 2000;
void setup()
{
pinMode(ledpin, OUTPUT);
}
void loop()
{
digitalWrite(ledpin, HIGH);
delay(del);
digitalWrite(ledpin, LOW);
delay(del);
}

16. TRY IT OUT 1: VERY SIMPLE LED BLINKING PROGRAM
int ledpin = 13;
int del = 2000;
void setup()
{
pinMode(ledpin, OUTPUT);
}
void loop()
{
digitalWrite(ledpin, HIGH);
delay(del);
digitalWrite(ledpin, LOW);
delay(del);
}
Global variables
Tells the Arduino that the LED is on pin 13
Delay between blinks as 2000 milliseconds
Setup
Tells the Arduino that pin 13 should be set as
an output
Loop
Sets pin 13 to provide 5 volts (HIGH)
Delays for specified length of time (del)
Sets pin 13 to provide 0 volts (LOW)
Delays for specified length of time (del)

17. TRY IT OUT 1: VERY SIMPLE LED BLINKING PROGRAM
int ledpin = 13;
int del = 2000;
void setup()
{
pinMode(ledpin, OUTPUT);
}
void loop()
{
digitalWrite(ledpin, HIGH);
delay(del);
digitalWrite(ledpin, LOW);
delay(del);
}

18. TRY IT OUT 2: LIGHT DEPENDENT RESISTOR & LED
int LDR_Pin = A0;
void setup(){
Serial.begin(9600);
}
void loop(){
int LDRReading = analogRead(LDR_Pin);
Serial.println(LDRReading);
delay(500);
}
Serial
This is a way by which your Arduino can “speak”
with a computer
Serial.begin opens the communications channel
Serial.print/Serial.println will “print” a message

19. ADDING “IF” STATEMENTS
If/else
Try to make your LED turn on when the light drops below a
certain level… add this code to your sketch
if (LDRReading < 500)
{
digitalWrite(ledpin, HIGH);
}
else
{
digitalWrite(ledpin, LOW);
}

20. TWEETING SENSORS 1: “SOMEONE’S RAIDING THE FRIDGE!”

21. WEATHER SENSOR NETWORKS

22. SENSOR NETWORK EXAMPLE: BIRMINGHAM
• The primary focus of the Birmingham Urban Climate project is to
provide a series of demonstration sensor networks to measure air
temperature
• The design is a nested network of sensors:
• ~30 full weather stations [coarse array]
• 131 air temperature sensors located in schools [wide array]
• ~100 air temperature sensors in the CBD (approx 50 sensors
per square km) [fine array]
• Birmingham will become the most densely instrumented urban area
in the world.

23. • The coarse array consists
of ~30 full weather stations
located across Birmingham.
• Urban equipment will be
located in secure primary
electricity substations (schools
in areas without substations)
• Further 4 in
the surrounding rural areas
to record background
conditions (i.e. Sandwell park,
rural schools)
• Average spacing: 3km
N
COARSE ARRAY NETWORK

24. • A full suite of weather variables will be
measured (air temperature, humidity,
wind speed, wind direction,
barometric pressure, precipitation,
solar radiation).
• Data loggers (CR1000),
communications and mountings
(Campbell Scientific)
• Vaisala WXT520 – precipitation,
wind speed, wind direction,
temperature, relative humidity,
pressure
• SKYE SKS1110 pyranometer
• Data Communication: GSM/GPRS
EQUIPMENT: WEATHER STATIONS

25. WIDE AREA ARRAY NETWORK
• The wide area array consists
of 131 air temperature
sensors located in schools
• Plus a few in ‘rural’ schools
/parks/farms outside
conurbation
• One per ONS medium super
output area (MSOA)
• Average spacing: 1.5 km
• Data communication: WiFi
via BGfL

26. EQUIPMENT: AIR TEMPERATURE SENSORS
• The air temperature sensors
(thermistor) and radiation shield are
a bespoke design from Aginova,
USA.
• Small and inexpensive (approx. £87)
• Data is relayed via existing WiFi
networks
• Battery life is estimated at 3 years
(checked annually)
Aginova Micro
• ‘Low-Cost’ Thermistor Temperature
probe (-30 to 70 °C)
• Precision 0.1 °C
• Accuracy ± 0.3 °C (20 °C)
• Stores data when |ΔTt – ΔTt-1| ≥ 0.1 °C
• Ability to store approx. 10 days data
• Secure Wifi data transmission back to
server through school wireless network
• Server hosted software collects data
from whole network and stores in
database

27. TRY IT OUT 3: MINI WEATHER STATION
Open the “WeatherStation” sketch
Upload to the Arduino
Check out the “Serial Monitor”

28. TWEETING SENSORS 2: TEMPERATURE RECORDS
How could you use an “if” statement
and some extra variables to record
maximum and minimum
temperatures
How about printing these as
messages?
We could then tweet the messages
(to cheat, look at
weatherstation_minmax)

29. SOIL MOISTURE AND DROUGHT MONITORING NETWORKS

30. COMPONENTS OF A FAMINE EARLY WARNING SYSTEM
• Rainfall
• Soil moisture
• Crop condition
• Socio-economics

31. FEWS: RAINFALL
Global Telecommunication System
Rain-Gauge Network in Africa
-40
-20
0
20
40
-20 0 20 40 60
Longitude (deg)
Latitude(deg)

32. FEWS: RAINFALL
Spatial
Temporal

33. FEWS: VEGETATION CONDITION

34. FEWS: VEGETATION CONDITION
Spatial
Temporal

35. COMBINED DATASETS TO PREDICT FAMINE
Found at http://www.fews.net

36. SOIL MOISTURE FROM SPACE

37. TRY IT OUT 4: SOIL MOISTURE SENSOR
int delaySecs = 5;
void setup() {
Serial.begin(9600);
Serial.println("values: 0-1024 ");
}
void loop() {
int raw_value = analogRead(A0);
Serial.print(" ");
Serial.println(raw_value);
delay(1000*delaySecs);
}

38. TRY IT OUT 5: CALIBRATED SOIL MOISTURE
Convert raw output to voltage:
volt_value = raw_value/1024*5
Convert voltage into moisture:
moisture = (volt_value*4.44–0.5)/8.4*100
(to cheat, look at
thetaprobe_calibrated)

39. TWEETING SENSORS 3: “WATER ME!”
How could you use
an “if” statement
and some extra
variables to send a
message when the
soil is too dry?

40. THANK YOU
thomas.smith@kcl.ac.uk
@DrTELS
@KCLGEOGRAPHY
facebook.com/KCLGeography
K7.47
Office Hours:
Mondays 16:00–17:00
Fridays 15:00–16:00