"
Team:Dundee/Project/SoftwareTheory
From 2013.igem.org
Revision as of 21:03, 3 October 2013 by Kyleharrison (Talk | contribs)
Moptopus - Hardware
The Moptopus is an electronic environmental sensor which was developed in order to monitor the day to day states of water reservoirs. The device would be placed in a water body and measures:
- Light Levels
- Temperature
- Humidity
- pH level of the water
- Dissolved oxygen level
- An on-board camera
Furthermore, the Moptopus device can be used in conjunction with the biological microcystin detection system that we attempted to develop. Presence of microcystin in water will trigger the production of Green Fluorescence Protein (GFP) by the E. coli detector. The Moptopus has been designed to quantify the amount of GFP produced by the excitation of GFP via a blue light and the capture of fluorescence emitted via a highly green light sensitive photodiode.
Platforms and Communication
In order to use the sensors and detectors mentioned before, the moptopus was created using two main control boards: the Raspberry Pi (Model B) and an Arduino (Mega 2560).
In order to use the sensors and detectors mentioned before, the moptopus was created using two main control boards: the Raspberry Pi (Model B) and an Arduino (Mega 2560).
A Raspberry Pi (http://www.raspberrypi.org) is a low cost, low power computer system which can fit in the palm of your hand. It has no onboard storage and instead runs various distributions of linux via insert-able SD Cards. The Raspberry Pi was chosen for our project due to its low cost and power requirements and the ability to easily program on it.
We implemented a Raspberry Pi as the control centre of the Moptopus. It carries out some information processing and controls the flow of information to any users. It is able to connect to the internet and allow a user to control the Moptopus while in operation. Our Raspberry Pi runs the Rasbian operating system (http://www.raspbian.org).
An Arduino (http://www.arduino.cc) is a cheap microcontroller, able to control and read voltages from metal pins which are connected to it. The digital and analogue input/output pins on our Arduino Mega have been used to control modules such as an LCD screen, light sensors, temperature sensors and the dissolved oxygen and pH sensors.
A number of methods of communication between the Raspberry Pi, Arduino and internet have been used. The Raspberry Pi is able to request data from a specific sensor by use of some of its own onboard pins. The configuration we used is called an I2C bus which is a serial communication method requiring just two pins on the Raspberry Pi and Arduino to communicate. Using this I2C bus, the Raspberry Pi asks the Arduino to take a specific measurement using one of the sensors.
The Arduino is also equipped with an Ethernet shield allowing it to be connected to the Ethernet port aboard the Raspberry Pi. This allows the streaming of data from the Arduino to the Pi. Finally, the Raspberry Pi has an added USB Wi-Fi device for connection to a local wireless network. This allows the Raspberry Pi to be communicated with and remotely logged into.
Sensors
Light
The sensors used to detect light were simple and cheap Light Dependent Resistors (LDRs). The specific LDRs used were Excelitas Tech – VT90N1. These light sensors were implemented in the moptopus in order to monitor the intensity of light falling on the lake on a day to day basis.
The sensors used to detect light were simple and cheap Light Dependent Resistors (LDRs). The specific LDRs used were Excelitas Tech – VT90N1. These light sensors were implemented in the moptopus in order to monitor the intensity of light falling on the lake on a day to day basis.
Temperature and Humidity
A combined temperature and humidity sensor was implemented to sense at the surface of the water with high accuracy. The sensor used was a SHT71, which provided temperature and humidity measurements to 2 decimal places. According to the datasheet for the sensor, the typical error present in these measurements was ±0.4% for temperature and ±3% for humidity.
A combined temperature and humidity sensor was implemented to sense at the surface of the water with high accuracy. The sensor used was a SHT71, which provided temperature and humidity measurements to 2 decimal places. According to the datasheet for the sensor, the typical error present in these measurements was ±0.4% for temperature and ±3% for humidity.
pH
The pH of the fresh water is of significance when determining whether an algal bloom is likely to break out and also has implications on the toxicity of the algal bloom. The pH sensor used was a silver/silver chloride probe produced by Atlas Scientific. This was accompanied by a data stamp via which communication with the Arduino system was possible.
The pH of the fresh water is of significance when determining whether an algal bloom is likely to break out and also has implications on the toxicity of the algal bloom. The pH sensor used was a silver/silver chloride probe produced by Atlas Scientific. This was accompanied by a data stamp via which communication with the Arduino system was possible.
Dissolved Oxygen
The dissolved oxygen concentration of a water body is significant in determining whether algal bacteria can grow in an explosive manner. Furthermore, it can also help detect the breakdown of cyanobacteria after an algal bloom. Thus, a dissolved oxygen sensor and accompanying stamp by Atlas Scientific was implemented and built into the Moptopus.
The dissolved oxygen concentration of a water body is significant in determining whether algal bacteria can grow in an explosive manner. Furthermore, it can also help detect the breakdown of cyanobacteria after an algal bloom. Thus, a dissolved oxygen sensor and accompanying stamp by Atlas Scientific was implemented and built into the Moptopus.
Onboard camera
The Moptopus was fitted with an onboard camera in order to view its surroundings. The camera selected was a Logitech C310 HD and this was mounted on the top of the Moptopus. By allowing a user to view the surroundings of the Moptopus, the conditions of the lake at any time can be viewed. The potential for such viewings would be to allow the monitoring of aspects such as the amount of waste rubbish which has been discarded into the water reservoir. Such waste can provide cyanobacteria with nutrients required for growth. Furthermore, should an algal bloom occur viewing of the site could allow for a monitoring of the growth pattern of the algae and in such a fashion be informative to potential action to reduce the likelihood of future algal blooms.
The Moptopus was fitted with an onboard camera in order to view its surroundings. The camera selected was a Logitech C310 HD and this was mounted on the top of the Moptopus. By allowing a user to view the surroundings of the Moptopus, the conditions of the lake at any time can be viewed. The potential for such viewings would be to allow the monitoring of aspects such as the amount of waste rubbish which has been discarded into the water reservoir. Such waste can provide cyanobacteria with nutrients required for growth. Furthermore, should an algal bloom occur viewing of the site could allow for a monitoring of the growth pattern of the algae and in such a fashion be informative to potential action to reduce the likelihood of future algal blooms.
Testing the Moptopus in Clatto
