- Feb 3, 2009
- 87
- 10
Okay, so some of you may have read previous posts about the Bionic Banana and may have even checked out my blog. I just did some testing today and thought I'd put up a more complete picture of what it is and the parts that went into it.
To sum up: It's a 1950's Coldspot fridge that's now an Arduino controlled 220 volt electric smoker.
This is the Arduino "Mega" board when I put it together for testing. The thing on the upper left is the Arduino, with a proto-shield on it, with the wi-fi shield on top of that. The tester is hooked up to the 220 volt relay that controls the oven element in the fridge. You can see the temp probe near it, the end of the red pen is almost pointing at it. The software in the Arduino monitors the probe I've designated as the pit temp. If it's below the temperature I set, it puts power to the relay which then allows power to flow through the oven element. I've programmed it to shut off the element when the temperature is 5 degrees less than the set temp, to account for excess heat from the element.
Here's my crappy label job on the side of the project case. I've got room to put maybe another 10 probes on the board, but don't have the probes currently. I'll add more as I need them. Temperatures are read on a computer on my home network, and as soon as a buddy at work gives me a hand with the PHP for my website I'll be able to monitor from anywhere and even change the temperature.
Here's the oven element roaring away. It almost looks white hot due to the color balance on my phone's camera, but it's just the normal "red hot" that oven elements get to. The metal drawer from the fridge is above it which kinda acts as a baffle right now and grease catcher. It's far enough away so I don't need to worry about grease fires, although it may not look like it in this picture.
Temperatures held very nicely, with the middle of the fridge and the top rack area being within a few degrees of each other.
After letting it warm up for a while I thought I'd do some load testing. To simulate a bunch of cold meat being put in I used a foil pan full of snow/ice. Recovery time was fairly quick, it dropped to high 160s after fumbling with putting the ice in and was back up to temp within 5-10 minutes. It worked pretty good, and showed the need to possibly re-work the baffle set up. The middle of the fridge was getting 15 degrees or so hotter than the pit temp. So with a better baffle I might be able to shave a few minutes off the recovery time.
As I think about it more though, it might be an issue of the pit probe being at the top where the somewhat cooled air is hitting it. You can see the probe at the top vs. the one hung under the pan. I guess another alternative I could do would be to put 2 or 3 pit temp probes in and program it to calculate an average between them.
All in all it was quite a fun project. The potential for improvements is there too. I'm going to change the web interface to be more user friendly, so I can set temp alerts and timers. It'd be nice to get an email or text msg on my phone telling me that one of the pork butts is at foiling temp, or that the ribs have been on for X hours and should be pulled or sauced. I'm looking forward to doing a few more tweaks then doing a huge batch of Ribs on it.
To sum up: It's a 1950's Coldspot fridge that's now an Arduino controlled 220 volt electric smoker.
This is the Arduino "Mega" board when I put it together for testing. The thing on the upper left is the Arduino, with a proto-shield on it, with the wi-fi shield on top of that. The tester is hooked up to the 220 volt relay that controls the oven element in the fridge. You can see the temp probe near it, the end of the red pen is almost pointing at it. The software in the Arduino monitors the probe I've designated as the pit temp. If it's below the temperature I set, it puts power to the relay which then allows power to flow through the oven element. I've programmed it to shut off the element when the temperature is 5 degrees less than the set temp, to account for excess heat from the element.
Here's my crappy label job on the side of the project case. I've got room to put maybe another 10 probes on the board, but don't have the probes currently. I'll add more as I need them. Temperatures are read on a computer on my home network, and as soon as a buddy at work gives me a hand with the PHP for my website I'll be able to monitor from anywhere and even change the temperature.
Here's the oven element roaring away. It almost looks white hot due to the color balance on my phone's camera, but it's just the normal "red hot" that oven elements get to. The metal drawer from the fridge is above it which kinda acts as a baffle right now and grease catcher. It's far enough away so I don't need to worry about grease fires, although it may not look like it in this picture.
Temperatures held very nicely, with the middle of the fridge and the top rack area being within a few degrees of each other.
After letting it warm up for a while I thought I'd do some load testing. To simulate a bunch of cold meat being put in I used a foil pan full of snow/ice. Recovery time was fairly quick, it dropped to high 160s after fumbling with putting the ice in and was back up to temp within 5-10 minutes. It worked pretty good, and showed the need to possibly re-work the baffle set up. The middle of the fridge was getting 15 degrees or so hotter than the pit temp. So with a better baffle I might be able to shave a few minutes off the recovery time.
As I think about it more though, it might be an issue of the pit probe being at the top where the somewhat cooled air is hitting it. You can see the probe at the top vs. the one hung under the pan. I guess another alternative I could do would be to put 2 or 3 pit temp probes in and program it to calculate an average between them.
All in all it was quite a fun project. The potential for improvements is there too. I'm going to change the web interface to be more user friendly, so I can set temp alerts and timers. It'd be nice to get an email or text msg on my phone telling me that one of the pork butts is at foiling temp, or that the ribs have been on for X hours and should be pulled or sauced. I'm looking forward to doing a few more tweaks then doing a huge batch of Ribs on it.
