Student Incursion
A Simple Introduction to Datalogging
With the V.E.L.S now mentioning datalogging at a lower level this student session will provide your students with a simple and engaging introduction to datalogging using LEGO NXTg robots , NXT interface and NXTg V2 software. Teachers who choose to sit-in on the session will also come away with a clear understanding of what datalogging is and some introductory activities
During this session students will use the LEGO NXT brick to collect data in a variety of situations starting with a test of sunglasses sun-blocking efficiency. The students will use a robot to datalog in a similar manner to the Mars Phoenix, collecting and storing data with the ability to respond to this data. Students will then use the collected data to analyse and compare the information and process it in a meaningful manner.
The class will use the latest NXTg V2 software with its simple graphical interface backed onto the industry standard LabView drive engine.
Supplied Equipment
My Software - ™ ® LEGO ®MINDSTORMS NXTg V2 / LEGO RoboLab 2.9.3 programming software
My Hardware-
- 15 Laptop Computers with all associated electrical leads and power-boards
- Data Projector
- 15 LEGO NXT basic robot with light, sound, ultrasonic, touch and angle sensors
(I can use your LEGO sets if you wish, especially if you have RCX robots)
Teachers PD
Datalogging Basics
Datalogging, regardless of the device and software used, employs a number of universal procedures. The more sophisticate dataloggers usually have more features with the range and sensitivity of sensors and the analysis software. We will learn the basics of datalogging with the simple NXT brick and sensors, consider experiment set-up and data analysis. The skills used here will easily transfer to other dataloggers. This is the perfect basic introduction to datalogging in the Math's and science curriculum
Suit teachers of years 4- 9
Recommended session length- 2 hours
Datalogging Basics - A simplified version for beginners
All robots use sensors to receive information from the environment and react(act)to this information according to their program, not all robots are dataloggers and not all dataloggers are robots. Notable examples of a datalogging robots are the MARS Pathfinder and Phoenix. Some dataloggers lack physical outputs to perform work, their sole function is to collect and analyse data from experiments and situations. LEGO NXTg V2 provides the option of using the NXT brick and sensors as a static datalogger or to build a device that is an active participant in the experiment eg. Stirs a solution and logs data.
A temperature probe has been added to the range of sensors, LEGO has formed a strategic alliance with Vernier. Now teachers have the option of plugging selected Vernier high quality scientific probes into their NXT bricks.
Have a look at the Vernier web site for experiments and ideas on how to use Vernier sensors with NXT
Connecting Point Software in Carlton has a complete range of NXT Compatible Vernier Sensors
The LEGO NXTg software offers two levels of datalogging: a basic level with a simple interface and a guided template and a more functional level integrated into the NXT program. Here the user can program both the robot's movements and actions and the collection and uploading of data to a graph. Data can be collected at a sampling rate of up to 100 samples per second
What is a datalogger? -
A datalogger is -
- an electronic instrument that takes measurements from the environment
- stores the information
- is able to feedback this information in a format that the operator can analyse, manipulate, apply calculations to, show as graphs and figures etc.
What does a datalogger device need to know?
In the case of LEGO NXTg V2, there is an easy default setting that has most of these instructions and the programmer has a simplified template that allows changes .
1 WHAT sensor do I wish to use?
2 WHERE is the sensor plugged in ( input port)
3 HOW OFTEN -interval/sampling rate - how often do you want to take the sample?
4 HOW LONG - duration or how many/ till when/ do you want to take the sample.
OTHER CONSIDERATIONS WITH LEGO MINDSTORMS for Education
1. Set the NXT brick so that it doesn't shut down automatically before the experiment is completed, change the NXT bricks default shut-down time. This is vital for datalogging over a long period
2. Make sure that you don't exceed the NXT bricks memory. Too many samples may cause the memory to fill up
3. Decide what experiment you wish to do/ data you wish to collect and what sampling rates will provide the most meaningful data to analyse.
4. Load the datalogging programs into the NXT brick. Do you need to pre load the program for mobile data collection and up-load data later or can you be tethered to the computer and see your data up-load in real time as it is collected? You have these options as well as the option to communicate both uploads and downloads via Bluetooth
5. Make sure that you have charged the NXT battery or have the transformer plugged in. Set up your experiment and plug in the appropriate sensors.
6. Run the datalogging program. Either upload the captured data as you go or upload later
7. Use the analysis tools to look at your captured data