Our good friend Lorelei needed some electronics help the other day, so Hans and Umbach invited her over for a fun-filled Arduino Party. She’s prototyping a force-sensing coaster that encourages people to drink plenty of water throughout the day, and the first step towards that goal is getting a force sensor to communicate with her Arduino.
She managed to pull an analog input from her FlexiForce pressure sensor and send it as a PWM output to an LED, but was still getting some terrible noise from the sensor. Umbach managed to dump it all to the serial monitor, and lo and behold, the Arduino was reporting readings that ranged from 0 – 1023 and everything in between!
Hans dismantled the circuit and rebuilt it, taking the Cat Sat On The Mat example from Tom Igoe’s wonderful Making Things Talk book as inspiration. In adjusting the sensitivity of the output from the sensor he tried all sorts of different resistors, from 1K to 100K, before ultimately settling on a 15K resistor. Umbach wired up the circuit to the Arduino, ran it into the serial monitor on Lorelei’s computer, and whammo! Success! A clean, analog signal coming from the FlexiForce!
We had a lot of fun, and encourage the rest of ya’ll to throw your own Arduino parties! Just don’t try to combine them with fondue parties… electronics don’t mix well with boiling oil and cheese… then again, they might go well with a chocolate fondue, so don’t let us stop you!