The dread timeout chair. It's every child's worst nightmare. It can also be every parent's worst nightmare. How do you keep your kid on the darn thing? You don't want to stay in the room constantly to see if the culprit has left the chair or not, but at the same time, you need to make sure they don't get up! We'll use the power of the LinkIT ONE to create an Automated Timeout Chair to alert you anytime somebody gets out of it.
Step 1: Supplies
A sensor, some speakers, and a LinkIT ONE. All we will need for our Timeout chair.
- LinkIT ONE Board
- Force Sensor
- 27k Resistor
- Speakers (ones that plug into 3.5mm)
Step 2: Hooking Up Our Force Sensor
The Force Sensor circuit isn't anything too complicated. The main component in it is a 27k resistor.
The force sensor does exactly what you think it might do: Measure force. Attach it to your LinkIT ONE just like the diagram above. Note that Fritizing doesn't have a LinkIT ONE in it's database yet, so showing the 'schematic view' (which would be more accurate) wasn't possible. You of course wouldn't actually attach this all to a breadboard when actually deploying.
Step 3: Hooking Up Our Speakers
Next, we'll need to hook up some speakers. This will allow us to have the LinkIT ONE play an alarm.
Because we're using a LinkIT ONE, hooking up speakers couldn't be easier. With an Arduino, we would have to get an external audio shield to hook it up, but with the LinkIT ONE, that functionality is baked right in.
Simply plug in your 3.5mm jack into the LinkIT ONE and you're ready to go!
Step 4: Moving Media to Your LinkIT ONE
Now let's put an alarm mp3 file on our LinkIT ONE. We have speakers hooked up, but now we need an audio file to play! This step isn't too difficult though.
Hook up your LinkIT ONE to your computer and change it to 'MASS STORAGE" mode (MS). Do this by switching the MS/UART toggle to the MS side, just like the diagram above.
Now, your computer treats the LinkIT ONE just like a USB or SD card. Simply open it up win your file explorer and click and drag the file over to your LinkIT ONE.
This will store your song file on the LinkIT ONE flash storage. Be mindful that the flash storage is very limited (only about 10mb), so make sure your file is small enough.
Step 5: Deploying the Code
The logic for this application is rather simple. Once it is turned on, we'll check if there is some force on the chair. If there is, then our naughty child is doing what they are supposed to and staying in timeout, so we won't make any noise. If we lose that force signal though, sound the alarm! We have a naughty kid on the loose!
Download the attached code file and deploy it to your LinkIT ONE to run the code.
Step 6: Deploying to the Chair
Just putting the force sensor right on a chair doesn't really work. Why? Because even a 3-year old can figure out pretty quickly what exactly is detecting if they are sitting in it or not. Instead I simply put a towel over my chair. I didn't really want to do anything permanent, because ideally we don't need a timeout chair in our house because our kids are so well behaved....That might be a little too wishful thinking. Plus, kids will believe almost anything about why their is a towel over it.
Anyway, put some tape on the force sensor to make sure it sticks to the chair, and then put the speakers somewhere close.
Step 7: And Now, We Wait...
And there you have it! A fully automated timeout chair that will alert you anytime your kid tries to skip out on a punishment. How's that for a tech-savvy parent? A key thing about this project is I tried to make it so it wasn't too permanent. This way, as they get older and you don't need a timeout chair anymore, you can take your LinkIT ONE back and do some more cool projects with it.