I'm actually amazed by the power of these little assemblies and I'm having trouble keeping focused because of all the possibilities!
The system I'm working on will require a few things:1- It will need an input for the ambient temp and:2- It will require a "Set Point" controlled by a potentiometer and:3- It needs to be "smart" enough to increase/decrease the blower speed based on how much difference there is between the "set Point" and the ambient temp and:4- open/close the water valve when the "Set-Point" requires more/less heat.For now I'm working out the blower speeds. I was thinking about having 4-5 different speeds using PWM. Most of the tutorials seem to focus on using a pot to increase/decrease speeds but I'm looking for guidance on how to have multiple speeds controlled via the Arduino. My first thought is using different pins to output different values. Pin 1- low, Pin 2- med low, pin 3 - med, etc. I understand that not all pins will output PWM but hopefully someone gets the idea.
I'm pretty familiar with relays and switching hi power stuff with lo power so I understand the concept. This just takes it to a whole 'nother level!Here's where I'm at:<image snip>The MOSFET on the right is an FDP7045 N-Channel Logic deal. (Like I know what that means ) I put the diode in there to protect the circuit from "flyback". I do actually understand that!
I'm still working out some of the PWM stuff like what values (0-255, right?) will equal which voltage and motor speeds.
It's only good for 500mA (or 40mA per IO pin IIRC)
I'm still on track with this... RS didn't seem to have ANY type of temp sensors in stock so I ordered some lm35's off ebay and I'll resume when they come in.Another problem I have is finding proper resistors so I ordered a big organized assortment of about 1000 1/4 watts.