Retailer Sparkfun has a sort of annual event. They offer free stuff to people in the form of a code they can use on a future purchase for solving puzzles/trivia or other challenges as they decide from year to year. This year I managed to come home for lunch with the contest still running and won $100 of free stuff from Sparkfun instead of eating lunch. It took almost my entire lunch hour but eventually I managed to get a captcha correct at the right moment and won a $100 code.
As luck would have it one of the items I wanted rapidly sold out that same day so by the time I got home from work I couldn’t place my order. So after a few days the item finally went back in stock and I placed my order. So far they haven’t shipped the order which is kind of a frown maker but I figure they’ll get to it eventually. Unfortunately this means I won’t get it until sometime next week but hey… it’s free!
Items for the coffee roaster project:
1 Crib for Arduino + Ethernet Faceplate – I’m hoping to mount a DB25 on the back of it and run that to a new PCB I want to get made.
1 RHT03 temp/humidity sensor module to try out for possible ambient sensing instead of the existing sensor due to soldering complexity
2 Current Sensors, jacks, and breakout for the jacks so I can breadboard them for now. – Two so I can sense total input vs only the amount going to the heater. I intend to monitor this for statistical purposes/energy tracking, control options, and
Several PCB mount potentiometers for the next phase when I have a PCB made.
Momentary pushbutton switches for a control button panel. To be wired to a single pin using analog sensing to figure out which buttons are pressed based on voltage/resistance readings.
For other projects:
2 solenoid controlled valves to shut off water.
Thumb joysticks… just because…
More Momentary pushbutton switches
I’m hoping to use some of the parts with one of the “pro” arduino boards or eventually figure out a smaller method using chips individually, a text LCD, a flow meter to monitor water gallons and tie it to the solenoid valves. In pursuit of better water quality I have what is effectively a low level commercial high flow reverse osmosis water system. It can produce around 700 gallons of reverse osmosis water per day. It has a rather large faucet and my intention is to plug a flow meter like they use on some water cooling computer projects to track the rate the water is coming out and then turn it off with the solenoid after a defined amount of time or a specific number of gallons flows through the flow sensor. I’ve had too many “accidents” where the 5 gallon water bottle overflows out the garage and down the driveway when I step away and get distracted.
I get told all the time… just set a timer. I say why set a timer when you can engineer a circuit to do it automatically for you!
I figure I’ll modify or make a Total Dissolved Solids monitoring circuits to feed the water purity info to the controller, perhaps let me run water for a few moments to get the sensor reading cleaner water since it starts off spiked high. It often does this during the first 20-60 seconds when I haven’t used it in a week or two. Finally it then starts tracking gallons for this run and possibly remember “lifetime” gallons for filter life monitoring too since my last replacement. To control it I’ll set the size bottle by the number of gallons it holds or a length of time to run on an LCD readout and using some buttons, press start, and wait for it to filter that much water. Once that happens the valve will disengage closing the water off since they fail closed.
As long as the water pressure is enough out of the output line this should work out reliably enough to have it stop short and then have a “spurt” setting button to pulse smaller amounts of water out to top off. My hope was to close off the input line AND the output line just to be sure it’s off in case something doesn’t work well. Worst case is the input line has more than enough pressure to work and I’d need to follow-up with a spurt and then close an output valve manually to keep the membranes completely wet.