The idea is very similar to the chicken coop dimmer. However, I want to add a readout and temperature adjustments.
The first step was disabling the heating pad's auto-off feature, which interrupts power to the heating elements if the pad has been on for more than 60 minutes. The Kaz HP215 SoftHeat heating pad, found at Wal-Mart, is the victim. After I got the case open, I examined the circuit within. I noticed a transistor near the output to the pad, and looked up the part number. It is a z0103 Triac, used to switch high-voltage power. Following the trace, I noticed it was connected to the mystery microcontroller's (try to find a datasheet for a 13-000022) pin 2. I hit it with the iron and pried the pin up. The device now thinks it is going to sleep (LED flashes) but it can't trip the triac, so my pad stays nice and toasty.
Step two is to get a display working with count up/down on the arduino. I used this great blog post to get me started. Only thing is I found out: my display's upper left led on the first digit is out, and I needed to reverse the binary in numbers to get it to work (ie 0b1000000 became 0b0111111, etc.).
Step three is to get a real reading on my thermistor finally. I made a spreadsheet to help me with the math. On the way to that spreadsheet, I made a csv for everyone. Yay! See the attachments section down there VVVV.
Young poultry needs a tightly regulated temperature to stay alive. During the first week, they need a heat source in the 95-100 degree range. My pullets are arriving tomorrow, so I was a little crunched on time when I came up with the idea of an arduino controlling a light dimmer via a continuous-rotation servo.
The simple control looks like this:
Temperature-dependent resistor > Arduino > Servo > Dimmer > Lamp
I'll update some of the hardware build when I get some time to snap pictures.
Here's the few I've taken so far, with probably cryptic captions:
Sourcing the gearpost: (yup, that's a binder clip arm)
Middle gear post hot-glued to switchplate, with washers for standoff:
Final gear glued to dimmer knob:
I use RFID a lot in my life:
Enter the RFID Door Strike. With minimal expense (~$70/door) I can have all the benefits of keycard-access entryways:
Here's what I've purchased so far, from sparkfun.com and seeedstudio.com:
Wiegand RFID reader
Electronic Brick Relay Module
Arduino Pro Mini
RFID Glass Capsule
The general flow works like this:
This is a mashup of the code on the seeedstudio site and some code found on the arduino.cc forums:
Here's a video of everything connected and working reading my glass capsule
I didn't want to solder headers on each of the three boards, as they will be a permanent installation.
I found these cool header pins in a broken VCR. They were used to attach the power supply board at a set height to the main board. I'm sure you can find something else that would work just as well.
With a coated paperclip (or a breadboard jumper, though these aren't as stiff), we can apply the header temporarily and securely.
Help me get a camera with macro mode by clicking on the ads!
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