I am in the process of creating setup that would close (opened by default) appropriate blast gates and then turn on dust collector, this is all based on electrical current sensing or manual input(button and/or hall sensor -on/off). Then it will open the gates first and turn on 10sec timer to run dust collection before shutting it down, if no other equipment is powered on.
I am new to this complex thing. I read a lot of forums and by trial and error I arrived here.
Let's imagine a woodworking shop with table saw, planer and edgebander. With one large dust collector, dust collection ductwork that has blast gates driven by compressed air pistons, which in turn controlled by the open/close solenoids.
Current sensor attached to the outlet, senses table saw is on. Arduino sends signal to close all dust collection gates except the one that goes to the table saw and turn on dust collector(.5 second to close or open, not constant on). When table saw is off, Arduino is still running dust collector with corresponding gate open for 5 seconds, later it opens all gates and continues to run dust collector for another 5 seconds. If no other inputs from another machinery is detected - turns off, leaving all gates open. Of course if other equipment is energized during table saw operation it will open corresponding gates, and close others until it is off and then again 5 sec + 5 sec and off.
For the example below I used thermistor instead of current sensor. When temp is more than 30C relay is activated for .5 second to power solenoid that closes the gate and when temp falls below 30C it powers relay for .5second that activates solenoid to open the gate. This sketch works, I arrived here by trial and error. But I have 8-10 blast gates so up to 16-20 relays that have to be activated accordingly for a .5sec. And inputs such as "air pressure sensor", "current sensor", "voltage sensor" and "push button as a backup". If I will write code like this it would be a disaster, I am sure there is a more elegant way of doing it. Maybe declaring Open Gate function and Close gate function and then just use gate+# to cycle. But I need help.
How would it be possible to rewrite "if" part more efficient and without it cycling relays on the loop.
I have pins 9-12 relays for 12v solenoids and pin 2 - relay that drives larger 3phase relay for dust collector. This example is run on Arduino Uno, however I will ultimately use Arduino Mega.
Here is a code:
//temperature sensor
const byte tempPin = A0; //the thermistor
#define beta 4090 //the beta of the thermistor
#define resistance 10 //the value of the pull-up resistor
//two relays control solenoid valves, one to open another to close.
//Energized for .5sec to drive piston with compressed air.
const int gate1Close = 12;
const int gate1Open = 11;
const int gate2Close = 10;
const int gate2Open = 9;
const int DustCollector = 2;
int passFlag = 0;
int passFlag1 = 0;
void setup() {
//relays driving solenoids
pinMode(gate1Close, OUTPUT);
pinMode(gate1Open, OUTPUT);
pinMode(gate2Close, OUTPUT);
pinMode(gate2Open, OUTPUT);
pinMode(DustCollector, OUTPUT);
}
void loop() {
//read thermistor value
long a = analogRead(tempPin);
//temp conversion
float tempC = beta / (log((1025.0 * 10 / a - 10) / 10) + beta / 298.0) - 273.0;
float tempF = 1.8 * tempC + 32.0;
//here is a part that needs C++ wizardry
//close gate when temp is over 30C
if (tempC >= 30 && passFlag == 0) {
digitalWrite(gate1Close, HIGH);
delay(500);
digitalWrite(gate1Close, LOW);
passFlag++;
passFlag1 = 0;
}
//open gate when temp is less than 30C
if (tempC <= 30 && passFlag1 == 0) {
digitalWrite(gate1Open, HIGH);
delay(500);
digitalWrite(gate1Open, LOW);
passFlag1++;
passFlag = 0;
}
}
Thank you all, any input is appreciated!
