Rob writes in… [via]
I’ve seen quite a few hacks related to controlling appliances, lights, etc over the years and just wanted to share a little info so that everyone has access to a cheap way to do it relatively safely. By trade I work in the building controls/integration industry and as a result I use these relays at work and at home(chicken coop control,light,etc)quite a bit.
The interface between your microcontroller of choice and the relay is a simple 555 relay driver circuit. I have included the pdf that inspired me to do it this way. The relay I use is the RIBTU1C. The reason I prefer this relay is that the coil will run on 9VC @ 20mA and the contacts will switch 10A @ 120VAC. Total cost for the RIB and a 555 is under $15 if you shop around. In addition the RIB has a partition inside the box between the line and control sides. There’s also room for a Radio Shack breadboard in there!
Safety First! Switching 120vac loads with a microcontroller - [Link]
I plan to make a pre-heater for my SMD works, and i will need a controller for the air heater. From my job i know the PID controllers and how efficient they are, but i did not really know how they work. After some research i did, i sound the “secrets” of the PID systems (and i also wrote a theory for PID systems). So, now i feel ready to turn theory into product. Many will say again that i could spent $40 to get a PID controller… Yes, i know… But i DON’T want to. For me, making projects is not a chore, it is my hobby, i do it for fun.
K-Type Thermocouple PID Controller - [Link]
Yuan writes in – [via]
Seems like sous-vide is a hot topic on your blog recently, I thought I’d throw my project into the mix: eltierfridge.wordpress.com
This is a Forebrain-controlled mini-fridge turned sous-vide cooker project. I didn’t put any buttons into the project, so everything is controlled over USB (target temperature, PID tuning, LCD backlight). Because Forebrain has built-in USB-HID functionality, no drivers are needed! The control app is written in Qt.
If there’s significant interest in the project, I’ll make an instructable and release the sources on Github!
peltierfridge – Mini-fridge to Sous-vide conversion - [Link]
Stian made this awesome sous-vide temp. controller, which he calls the “SousVide-O-Mator”. Built around an ATMega328 with the Arduino bootloader, it uses a DS18B20 temp. probe to monitor the temp, a 20×4 LCD to communicate with the user, and a solid-state relay to switch the rice cooker on and off. It also features one of the neatest, cleanest stripboard layouts I’ve ever seen (style counts!). He writes:
My brand spanking new homemade Sous Vide controller (PID controller for cooking). By connecting the relay to my rice cooker and putting the probe and a small aquarium pump inside I’m able to very accurately control the water temperature..
This is basically a heating immersion circulator as used by some fancy restaurants – readily made equipment cost in the range of $1000.. So I made one myself on the cheap (controller + rice cooker + water pump). This can be used to cook meat to perfection
Perfect for Sous Vide cooking! ( For more information about Sous Vide: http://en.wikipedia.org/wiki/Sous-vide )
SousVide-O-Mator - [Link]
This project got started with the culmination of several things seeing several cellphone hacks over the years on Hack A Day, owning a car with a remote starter, having an office that is too far away from the parking lot to use the normal key fob and the ultimate motivator… winter weather! Of course some people think you’re crazy when you want a feature that just isn’t “out of the box”. Those are not the kind of people I would be expecting to read this. I figured I would document my little project and hopefully you enjoy it.
Remote Starter Extender Project - [Link]
XBMC is a cross platform Media Center Application with 10-foot UI. In this project we develop USB port base controller for XBMC application. Main functionality of this controller unit is to provide remote control interface, LCD base player information panel and rotary encoder base controller for XBMC. With this given hardware design and software programs, user may be able to control XBMC without using standard input devices such as keyboard and mouse.
This device is design to work with XBMC Version 10.1 (codename Dharma) or newer versions. Older version of XBMC may not work this system because of the differences in its Web Control Interface. This system is design to work with XBMC – JSON RPC interface.
XBMC USB Controller - [Link]
These days, smartphones do just about everything, but what about opening your front door? On this week’s episode of element14’s “The Ben Heck Show,” Ben transforms everyday household products into time-saving and convenient solutions, including an automated door buzzer he controls from his smartphone. Ben also transforms a manual thermostat into an automated system that adjusts to pre-set temperatures at pre-programmed times. Check out the full episode at element14 when you have the chance, and see home automation at its finest.
In addition, show fans are invited to join the discussion online at element14 to engage with community members, submit project ideas for a future episode and enter for a chance to win one of Ben’s builds featured on the show, including his Xbox 360™ CD disc changer and portable 3D printer.
Modder master Ben Heck morphs his apartment into a “smart home” - [Link]
Alright, I think it’s about time for this silly article on plasma arc waste disposal to get knocked off the top of my site, don’t you? It’s just fluff, honestly. Filler. And I’m tired of looking at it. So how about a post on a real project for a change? Sound good? Great.
First though, a quick gripe. I hate waiting for parts to arrive. Specifically “last” parts. Like that final DigiKey order, or in my case, a shipment of PCBs from Advanced Circuits. You see, I now have everything I need to complete this really exciting new device I’m designing at work, except for the PCBs.
Garage door opener – [Link]
This project described a stereo audio amplifier using two LM386 ICs and a PIC microcontroller to control the volume of the two output speakers. The project uses a DS1868 digital potentiometer that creates a voltage divider network at the input stage of LM386 to control the fraction of signal fed to the amplifier. The potentiometer wiper position is varied digitally by the microcontroller based on the user inputs.
Digital volume control for a stereo audio amplifier – [Link]
Hot on the heels of my last hack (no pun intended), is my latest project, a PID (proportional – integral – derivative) controlled hotplate. The inspiration for this project came from this post on MightyOhm.com. I choose to build it because I wanted to increase my knowledge on PID controllers and also wanted to get into soldering surface mount components. I got lucky and got all of the components for this project for under $20. Check out after the break for the build details.
Homemade PID Controlled Hotplate - [Link]