Team:UNIK Copenhagen/Arduino
Arduino protocol
Aim
The aim of this experiment is to build a prototype for conducting gradient temperature experiments. We will do this by programming an arduino to receive input from 5 DS18B20 temperature sensors and display this data. More specifically our experiment will involve testing moss’s survivability at 5 different temperatures by placing petri dishes of wild type moss on a temperature gradient.
Materials
Method
Physical set up
Arduino Hardware
Removing thermosensors from breadboard
Soldering:
- Remove about 2 cm of wire insulation
- Twist both ends of the wire into a braid
- How to connect the wires:
- Inline splice: crisscross the wires and twist them together
- Pigtail splice: have the two wires parallel and twist them together
- Choose either of the above options, however make sure that the wires are well physically connected before beginning to solder
- Use an alligator clip or some other device to secure the wires in place so that they do not move during the soldering
- Heat soldering iron and put some soldering on the tip of the iron
- Knock off excess solder onto some paper
- Tin the tip again (step 6)
- Gently place the tip of soldering iron against the wires: heat the wire and melt some solder onto the wire joint
- The solder should begin to flow onto the wire
- Do this until the wire joint is completely covered and silver
One thermosensor
- Insert DS18B20 sensor into breadboard with outer pins on rows 1 and 3 and middle pin on row 2.
- Insert resistor into breadboard with pins going into row 2 and 6
- Connect a wire:
- From pin 10 on Arduino to pin 2, in order to get data input from thermo sensor
- From GND ( ground pin on the arduino) to row 1
- From 5V (power pin on the arduino) to row 3 and 6
Multiple thermosensors
This has a similar setup to the one above, however now there are multiple thermosensors connected in series to pin 11 and use the same resistor connected to the first thermosensor.
Two sensors connected according to the method shown to te method shown above
Arduino Software
One temperature sensor
- Download the Arduino Software IDE (Different versions depending on what operating system you have)
- Install the “One Wire” library in order to run the code for the temperature sensor This code looks like this:
- Then we can run the Serial Monitor from the Tools menu which should give you a reading of the temperature every second
Multiple thermosensors
For Multiple thermosensors we need to install the following libraries:
The code looks like this:
With data being shown as output on the computer in the following form:
Conclusion and evaluation
Crimping technique would have been more effective as it is less likely to change the resistance of the wire. This is important as the thermosensor operates by measuring the change in resistance, which means that if there is a change in resistance of the wire it will be less effective at providing accurate temperature data output.
We used super glue to tape the sensors onto the aluminium rod as we did not have access to a thermal adhesive such as this one the Arctic Silver Thermal Adhesive. Glue can disturb the insulating capabilities of the thermosensor.
Further possible sources of error: