Sound the Alarm… Eventually (Annalise Irby, Trailer Automation)

This week, the Trailer Automation team has continued testing the sound sensor that recently arrived (shipped via Amazon). We are still encountering problems with the values that appear on the Serial Monitor, a screen associated with our sound sensor’s Arduino code which constantly interprets the sensor’s analog input into digital numbers. The Serial Monitor constantly feeds values from the sensor and then Arduino board onto our screen, which would/should be incredibly helpful as we calibrate this mysterious sensor – but it is not working as intended.

Instead of changing values when we test it with background noise (like the hum of an AC unit), sharper nearby noises (like clapping or shouting), or relative silence, the sensor still spits out seemingly random and arbitrary values. It doesn’t seem to be responding to changes in environment (analog input), which could mean it’s broken, but more likely means that we are missing some vital part of the calibration process.

The frustrating part is that the Instructable that we were working off of does not adequately explain this process. Perhaps its author (“electronichamsters”) assumes that the answers are too obvious and don’t need to be spelled out. But we’ve encountered other inconsistencies with this Instructable in the past, like vocabulary (ex. RFM gateway) that no other Internet resources seem to use. With this in mind, we are trying to wean off this Instructable, and doing more research on other possible models which are more reliable.

Hopefully, the coming weeks will bring our team more success as we try to elicit a response from our sound sensor. No matter how irritated I get with that little sensor, I always remind myself – computers don’t make errors. Humans do! The error must be in our code or our breadboard. The only problem is that our breadboarding instructions are not very clear; we’re basically just trying to piece together several different videos, graphics, and instructables into a physical product that actually works for our particular situation. It works about as well as designing our own lesson plan, then teaching it to ourselves – which I suppose is what engineers and innovators do in the real world. I’m still holding out hope that we can finish this whole project on schedule (that is, before the Maker Faire), but before we can add on the other sensors, we have to overcome this huge obstacle! And from such a tiny, tiny sensor.