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I got introduced into the world of Arduino when two friends informed me about this little device independently from each other. I read about it and was sold immediately. What if I had this so many years ago, how much would I have invented already, what would I have made? What would my house have looked like?
I ordered one directly and there I was playing with lights, sensors, etc. But then? ..... it has the potential to control everything, but what? What should I make?
I think this is where more people get stuck. What should I do with it?
Coincidently I just finished constructing a coffee roaster, made from an ordinary popcorn machine. In basic it works by a fan blowing air past a heating element through the green coffee beans. By controlling the fan speed, I was able to control the temperature of the air roasting the beans. But, the roasting process turned out to be quite hands on, as the temperature needed to be kept constant following a profile, which was done by measuring the temperature the whole time and adjusting the fan speed with a pot meter.
That, I thought, should be automated....
I ordered one directly and there I was playing with lights, sensors, etc. But then? ..... it has the potential to control everything, but what? What should I make?
I think this is where more people get stuck. What should I do with it?
Coincidently I just finished constructing a coffee roaster, made from an ordinary popcorn machine. In basic it works by a fan blowing air past a heating element through the green coffee beans. By controlling the fan speed, I was able to control the temperature of the air roasting the beans. But, the roasting process turned out to be quite hands on, as the temperature needed to be kept constant following a profile, which was done by measuring the temperature the whole time and adjusting the fan speed with a pot meter.
That, I thought, should be automated....
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Signing UpStep 1Materials used
For this project I used:
-1x Arduino Duemilanove
-1x Arduino protoshield v2 (sparkfun) with breadboard
-1x 12x2 LCD screen (use a parallel one, would recommend a serial LCD)
-1x electric popcorn machine
-4x 1KOhm resistors
-1x small push button
-2x 1KOhm potmeter variable resistor
-1x IRF540N
-1x temperature sensor ZTK 33 V/7 mA
-1x solid state relais S216S02 (sharp)
-19V adapter (used the one of my laptop)
-plugs, wires, etc
-1x Arduino Duemilanove
-1x Arduino protoshield v2 (sparkfun) with breadboard
-1x 12x2 LCD screen (use a parallel one, would recommend a serial LCD)
-1x electric popcorn machine
-4x 1KOhm resistors
-1x small push button
-2x 1KOhm potmeter variable resistor
-1x IRF540N
-1x temperature sensor ZTK 33 V/7 mA
-1x solid state relais S216S02 (sharp)
-19V adapter (used the one of my laptop)
-plugs, wires, etc
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To add function, mount it on a threaded rod so you can tune the level easily.
This is the method used in polyethylene plants to measure the level in holding tanks. Poly is made as small pellets, shaped like a coffee bean but smaller. Of course they don't move around, just fill or drain.
Again, great job.
Is there a recommended substitute that will read this higher temperature?
Thanks. I'm definitely going to study this -- I haven;t even experience with Arduino.
Where do you put the probe?
Whats the maximum temperature that this sensor can read?
I was thinking of building something similar. But using the
max6675 thermocouple amplifier. Is there any advantage to your approach over the max 6675? The 6675 is about $12.00 ( from sparkfun.)
Sorry for the late reply. The temperature sensor is a T sensitive resistor which can measure up to 300C if I am not mistaken. I got it from a local electronics supplier and choose this one as it was the only one this width measuring range. The sensor is located in the metal tin inwhich the popcorn or beans are roasted, just above the air sleaves.
Recently I have been unsatisfied with the temp readings. When I roast beans and measure the temp externally during the process with the thermometer I also used to calibrate the sensor, I get a deviation of about 10C, which is way too much. Therefore I am now also considering a thermocouple and already got myself the MAX6675. The pins on this chip are however soo short that you need a small breakboard to attach it to and extend its pins (also orderable from sparkfun I think). I dont have any experience with thermocouples, but as they are used widely in industry, I assume they are more reliable to the thermistor I now use. Due to limited time at this moment, I am not sure when I will start with it.
Let me know what your progress is
Regards, Rutger
A T/C will be a lot better.
Steve
I am 3/4 of the way through building your system.
Do you have an alternative for the sharp relay as it is proving difficult to source in Australia and there are some issues about importing them into the country due to local sharp licensing issues.
Thanks
It isn't important which brand of relay you use. I prefer to use a solid state one , but see no reason why anormal one wouldn't work. The most important is that it is able to switch the high current of the coil. You can calculate the amperage you need. You can find many types on ebay, although some are quite bulky.
Recently I made some modifications to the roaster, but I have been to busy to finish it and put them online. In the program currently in this instructable I start the roasting by directly turning on the heat control. Because the T is below the setpoint of 150C, the fan speed is automatically turned low and you need to fiddle with the min fax speed settings to keep the beans moving. I adjusted this by heating up the beans till 150C degrees while having the fan at max speed. This works without a problem, it just takes some seconds longer to reach 150C, but the whole min fan speed issue is solved. The reason for this is that once the beans reach 150, a lot of water has evaporated and their density is much lower.
I still want to change the temp sensor for a thermocouple, as I am in doubt about the accuracy of the one I use now.
Hope this is of any help to you. I would be very interested in the final result, so keep it posted.
Rutger
A microphone could not only tell if the beans were moving but could also tell when they crack :)
It would be possible to solve the minimal fan speed settings when combining both heating and fan speed control, as the coil is able to heat the beans enough for the water to evaporate and them to get lighter. So first controlling the heat with the coil untill the temperature cannot get higher and then switch to fanspeed control. Although this only requires software changes, it is a bit more complicated. I'll think about it :)
Anyway, I'd be curious to see this done...I'd like to mod mine to do something similar...
I surely wouldn't leave it running unattended, but with some common sense you will not burn down the house.
Since I came from an already working system (see the other instructable), this was the more logical way to go for me. But your solution would solve the minimal fan speed problem.
Controlling the heating coil with the Arduino would be easiest to connect the solid state relais with a PWM port. I am not sure if the solid state relais and the heating coil (1200W) could handly very frequent on/off switching. (My electronic knowledge is rather limited).
Wowed.
Justin
Does/how hard would it be to make it do this every morning at 7, make the coffee, pour it, and add cream?