#Scratch wedo download#
Don't worry, you can download the program that I wrote for this project form website and run it on your computer. You can even share a program over the internet.
#Scratch wedo code#
You drag and drop these blocks that represent code into the program and run it. Literally the graphic representation of the program/script. The main Lego parts (aside from the WeDo kit are: the gear box, 3 axles, generic building pieces and some Bionicle joints. WeDo website: PicoBoard: If you have a child who likes Lego or you have a friend with kids who like Lego then just ask them to put this together for you. Here are a few websites for reference as we go along. The prototype is so easy to work with that you can do much more than we've described. Out apparatus can accept from 1-40 small sample vials or up to 10 larger sample bottles. OK, back to the project, a Fraction collector can cost 4,000-15,000K$, ours cost less than 150$ and has a "build time" of less than 30 minutes (if you have the Lego and WeDo parts and you download our program script from the "Scratch" website). You can even have multiple sites contributing sample to the containers as they stop and start at different positions. This project can be easily reconfigured to include a proximity switch and light sensor with an LED circuit.
You can stop the sample for a constant amount of time or program the sampler to stop at the magnets, fro example, for increasing or decreasing amounts of time for each sample. Another variation on this theme would be to start with sample containers that had something in it, for example "algae" and stop in a magnetic field (between two magnets) for specific amounts of time or in front of an LED to give the sample different amount of light at a specific wavelength. It stops a sample bottle or vial for a given amount of time to collect some drips from an outflow tube and then moves the next empty sample container into position. To start with, If you wanted to sample the outflow from something over time or collect timed samples then you might want to use a fraction collector. We'll explain what a fraction collector does and how its used with column chromatography. The program that we wrote to control the Servo Motor and Sensor is also downloadable from the Scratch Website and you can easily change it for your own use.
Each tube stops under a sample outflow to collect a few drops then moves on to the next empty tube to collect the next sample. It then tells the program to stop the motor for a certain amount of time, then repeat the process for the next empty tube. The motor turns a sample wheel that holds empty tubes until the sensor "detects" a tube in front of it.
In a nutshell, the scratch program gets input from a sensor and controls a servo motor. We have taken the system through hundreds of cycles and it works reliably. The only cost is for the Lego WeDo robotics components and the Lego pieces used for the apparatus. We used the free downloadable "Scratch" graphical programming language and the Lego WeDo robotics kit to make this Auto Sampler/Fraction collector.
#Scratch wedo how to#
We demonstrate how to make a reliable and useful scientific instrument called a "Fraction collector" for use with column chromatography applications or educational science projects. Siderits R, Swift M, Lecorchick W, Ouattara O, Siderits I, Malik F.
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