Ceci est une ancienne révision du document !
Not much left to do on the Brewduino now.
I’ve added some LEDs just to indicate what’s going on. The green LED is to show that the device is on and OK. The red LED shows that the switch is on and, thus, the heat mat is on and heating up the fermenting vessel. Finally, the blue LED shows that the switch, and heat mat, are off, and that the vessel is cooling down to room temperature.
The best way, I found, to test the whole device is to have the DHT22 under the lamp because, when the lamp comes on, the heat from the bulb will bring the temperature up and the whole system goes into an on/off cycle. The lamp heats the DHT, and when it goes off, the DHT cools down, the threshold is reached, and the lamp comes back on again. And so on.
The only adjustments to the code are to define the LED pins:
int power = 43; int red = 47; int blue = 39;
Then, set the modes to output, and put the (power) green LED on (code is shown on the next page, top right).
The temperature check statement now includes the states for the red and blue LEDs (code is shown bottom right).
You’ll note that I’ve also fixed the SSR state so that the light is LOW (on) when the temperature is below 24, and HIGH (off) when above 24. This is the correct procedure for the heat mat.
Well, we’ve pretty much come to the end of the Brewduino. Apart from swapping out the lamp for the heat mat, everything is in place and working. Obviously, everything will need to go in a nice box, and the Arduino will need a power supply (as I need my laptop!), but everything is working, and that’s the main thing.
No doubt I’ll be tinkering with the code between writing this up, and you reading it, but the code referred to here is at: https://gist.github.com/ronnietucker/7fc62df161107116cf93, and marked as revision 6.
If you can think of anything to add/change in the Brewduino, please feel free to email me your suggestions: ronnie@fullcirclemagazine.org