Pi Chef Design Challenge - Automatic Dough Shaper - blog #2

Time is marching along and it's time for an update!

My first post was a general overview of my project: Automatic Dough Shaper - Blog #1

The idea is essentially this: dough goes in, gets flattened, shaped, baked, and comes out.

Project Timeline:

Week 1: Order parts
Weeks 2-3: Set up Raspberry Pi and toaster oven control
Weeks 4: Roller control
Week 5-6: XY control
Weeks 7-9: Fine tune functionality and user interaction
Weeks 10-11: Troubleshooting and last minute fixes

While I was waiting for my kit and other parts to arrive, I began working on the toaster oven control circuit. My plan is to create a mains power switching circuit using zero cross detection, a triac, and a thermistor. This way I can plug the toaster oven into the circuit, and by having the thermistor in the oven acting as feedback, I can control when the oven turns on or off and to what temperature it heats. So far I've set up the circuit and tested the zero cross detection part with an arduino.  For the schematic U1 is the H11AA1 optocoupler, R1 is 10k ohms, R2 is 470 ohms.

I sent a square wave signal from my arduino to the circuit and then used the arduino to read when the chip sensed the "zero cross" from the ZC_out pin. I plotted both signals against each other by sending the information over serial to a live data plotting program in Python. Here you can see that the circuit is giving the desired result.

Now I need to set up the rest of the toaster oven control.

Last Monday, my kit arrived and I got to work setting up the pi. (The only other time I've used a raspberry pi was my neighbor's and he did all the set up for me, so this was a good adventure.) I only have a laptop, so I did a bunch of reading online and figured I could set up the pi and then enable it to work remotely with ssh. So I did the initial set up at the BYU library, got the camera working and entertained myself and my daughter as I experimented with it. I didn't know how much fun a raspberry pi with camera could be! This makes me want to do a bunch of other fun projects, but those will have to wait until April.

When I got back home, I plugged in the pi and tried to connect remotely before I realized that I had never connected my pi to my home internet. With no other display to connect to, I had no way to connect to the internet or even properly shut down my pi! I got all worried that I would ruin all the work I've done and have to re-format the SD card. After reading several articles and blogs, I tried creating a sub-network from my computer to the raspberry pi using an Ethernet cable and accessing the pi using Putty and VNC, but I couldn't get either to work! Luckily my brother-in-law knew how to solve my problem!  I had it all set up right, but I didn't know the right IP address to use. He showed me how to find that and then (after I connected my pi to the internet) how to go online and find the IP address assigned from the router and remotely access the pi from my laptop without cables. What a godsend!

Of course, then he told me that I would have probably been okay if I had unplugged the pi. (Another perfectly good panic - wasted!)

The only thing is I didn't know how to get the pictures off my SD card. My computer said I needed to format it in order to access the data, but I didn't know if I would mess it up by doing that so I'll have to research it.

This week things are going to get heated up with the oven control!

(Let's hope nothing actually gets burned up.)