About
In this post, I’ll show my DIY solder paste dispenser. It’s powered by a 12V adapter and can be operated by a footswitch(connected via banana connectors). It uses a small membrane air pump/compressor to dispense the solder paste/flux. Additionally, there is a solenoid air valve connected to the airline so the pressure can be released after you let go of the footswitch which prevents the solder paste or flux from oozing out. The pump and valve timing is controlled through a relay module by an Attiny45 microcontroller.
I simply hot glued the components inside the project box. It’s not the prettiest look but it gets the job done.
Electronics
Software
This is the very simple code that controls the dispenser. I used an Arduino with the Arduino IDE to program the Attiny45.
const byte relayPin = 2;
const byte switchPin = 1;
const byte airPumpPin = 0;
bool state = false;
bool prevState = false;
void setup()
{
pinMode(relayPin, OUTPUT);
pinMode(switchPin, INPUT);
pinMode(airPumpPin, OUTPUT);
digitalWrite(airPumpPin, HIGH);
digitalWrite(relayPin, HIGH);
}
void loop()
{
delay(10);
if(digitalRead(switchPin) == HIGH)
state = true;
else
state = false;
if(state)
digitalWrite(airPumpPin, LOW);
else
digitalWrite(airPumpPin, HIGH);
if(prevState == true && state == false)
{
digitalWrite(relayPin, LOW);
delay(250);
digitalWrite(relayPin, HIGH);
}
prevState = state;
} Demonstration
