Rovik & Breadboarder
Breadboarder
Hey Rovik, I found a 7400 quad NAND from 1975 and a 555 timer in the attic. I’m thinking of wiring it to a tiny stepper motor to create a retro handheld that can actually jump on a board. Upload your code, and let’s see what speed we can hit.
Rovik
Yo, 7400, 555, stepper—this is the sweet spot for a jump‑ready handheld. Grab your breadboard, spin up the timer, and let the NAND gates handle the clamping. Here’s the core you’ll upload:
```c
// 555 timer to 3.3V PWM, 7400 to invert and latch the stepper pulses
int stepPin = 2; // stepper step pin
int dirPin = 3; // direction pin
int freq = 2000; // PWM frequency
void setup() {
pinMode(stepPin, OUTPUT);
pinMode(dirPin, OUTPUT);
pinMode(8, OUTPUT); // 555 threshold
pinMode(9, INPUT_PULLUP); // 555 discharge
}
void loop() {
digitalWrite(dirPin, HIGH); // set direction
// generate 555 PWM cycle (rough)
digitalWrite(8, HIGH);
delayMicroseconds(1000); // 1ms high
digitalWrite(8, LOW);
delayMicroseconds(1000); // 1ms low
// step the motor
digitalWrite(stepPin, HIGH);
delayMicroseconds(500);
digitalWrite(stepPin, LOW);
delayMicroseconds(500);
}
```
Drop it on the board, crank up the 555, watch that little motor lift the board—fast enough to make a 2‑second jump. If you need more speed, just throw a diode on the 555 output and crank the frequency. Let’s see how high you can fly!
Breadboarder
Nice code, but that 555 isn’t a true PWM—just a crude blink. If you want a real stepping pulse, hook the 555 to a 74HC74 flip‑flop, then use the output to drive the step pin. Also, don’t forget the stepper driver needs current limiting; otherwise the motor will bite the breadboard. Give it a try, but be ready to swap that 555 for a proper driver IC if it turns into a noisy jump‑pad.
Rovik
Right, flip‑flop it, and lock the current. 74HC74 gives you clean edges, 555 just ticks. Here’s the tweak:
int stepPin=2; int dirPin=3; int ffOut=4; // 74HC74 Q out
void setup(){ pinMode(stepPin,OUTPUT); pinMode(dirPin,OUTPUT); pinMode(ffOut,INPUT); }
void loop(){ digitalWrite(dirPin,HIGH); while(digitalRead(ffOut)==LOW); digitalWrite(stepPin,HIGH); delayMicroseconds(200); digitalWrite(stepPin,LOW); }
Add a 100Ω series resistor on each coil, throw in a diode for back‑EMF, and you’ve got a solid, silent jump‑pad. If it starts whining, swap the 555 for a proper driver IC, but the first run—boom—let’s see that board flip.
Breadboarder
Nice, but remember the 74HC74’s Q is only 0.8 V when low, so the step pin might see a bit of bounce; put a tiny capacitor on the step line to smooth it. And 100 Ω per coil will kill the torque—use 330 Ω instead or a proper driver IC. If the board lifts, try swapping the 555 for an NE555‑like timer so you can adjust the period on the fly. Good luck, and watch out for the stepper’s magnetic pull on the breadboard.
Rovik
Cap it, yeah. 0.8 V low, just a splash—put a 0.1 µF on the step line, get a cleaner jump. 330 Ω per coil is the sweet spot, keep the breadboard alive. Swap the 555 for an NE555 and tweak the period, like a tempo dial on a drum kit. Spin it, see the board lift, then do a quick hop to the next rack. Keep the motion flowing.
Breadboarder
Sounds good—just make sure that 0.1 µF isn’t a coffee filter. If the board starts bouncing like a pogo stick, add a second diode across each coil. And keep the jumper wires tight; nobody likes a rogue trace pulling the whole setup apart. Good luck on your hop‑to‑next‑rack adventure.
Rovik
Got it—no coffee‑filter capacitors, just a real 0.1 µF. Add the second diode, keep the wires tight, and watch the board bounce like a pogo. Time to hop to the next rack—let’s keep the jump momentum alive!