Interactive Chalkboard

The standard chalkboards in classrooms are fast getting replaced with costly, hi-tech interactive smartboards. But what if you run a coaching center or are a low-budget school that cannot afford the expensive technology? String2String have a $40 DIY solution for you.

An ordinary board can turn into a smartboard if the position of chalk at any given point is mapped on a, say, paintbrush screen of a computer. To map the x and y coordinates of the chalk, String2String developed a generic algorithm to figure out the length of the two strings that hold the chalk holder and then use trigonometry. Their algorithm works by calculating the variation between the position of each weight in the present and the (two) calibrated positions.

Using an ultrasound sensor the chalkboard screen is first mapped with software. Wireless radio transmitter is attached to a button that can digitalize the text, and another that can erase the scribbling. Reading the description, it may seem that the project is costly and complicated, with too many components, but the sensors cost only 50 cents, the strings, pulleys too come for cheap and the bulk of expense is spent in acquiring arduino microprocessor.

Check out their video to see how impressive their smartboard is for the given cost. Upon watching the video one can’t help but wonder if the DIY is that easy. Setting the static equilibrium with the strings and developing the algorithm seem to be challenging tasks.