easystepper: very simple 4-wire stepper driver

easystepper/easystepper.go

@@ -0,0 +1,84 @@
+// Simple driver to rotate a 4-wire stepper motor
+package easystepper
+
+import (
+	"machine"
+	"time"
+)
+
+// Device holds the pins and the delay between steps
+type Device struct {
+	pins       [4]machine.GPIO
+	stepDelay  int32
+	stepNumber int32
+}
+
+// New returns a new easystepper driver given 4 pins numbers (not pin object),
+// number of steps and rpm
+func New(pin1 uint8, pin2 uint8, pin3 uint8, pin4 uint8, steps int32, rpm int32) Device {
+	m1 := machine.GPIO{pin1}
+	m1.Configure(machine.GPIOConfig{Mode: machine.GPIO_OUTPUT})
+	m2 := machine.GPIO{pin2}
+	m2.Configure(machine.GPIOConfig{Mode: machine.GPIO_OUTPUT})
+	m3 := machine.GPIO{pin3}
+	m3.Configure(machine.GPIOConfig{Mode: machine.GPIO_OUTPUT})
+	m4 := machine.GPIO{pin4}
+	m4.Configure(machine.GPIOConfig{Mode: machine.GPIO_OUTPUT})
+	return Device{
+		pins:      [4]machine.GPIO{m1, m2, m3, m4},
+		stepDelay: 60000000 / (steps * rpm),
+	}
+}
+
+// Move rotates the motor the number of given steps
+// (negative steps will rotate it the opposite direction)
+func (d *Device) Move(steps int32) {
+	direction := steps > 0
+	if steps < 0 {
+		steps = -steps - d.stepNumber
+	} else {
+		steps += d.stepNumber
+	}
+	var stepN int8
+	var s int32
+	for s = d.stepNumber; s < steps; s++ {
+		time.Sleep(time.Duration(d.stepDelay) * time.Microsecond)
+		if direction {
+			stepN = int8(s % 4)
+		} else {
+			stepN = int8((s + 2*(s%2)) % 4)
+		}
+		d.stepMotor(stepN)
+	}
+	d.stepNumber = int32(stepN)
+}
+
+// stepMotor changes the pins' state to the correct step
+func (d *Device) stepMotor(step int8) {
+	switch step {
+	case 0:
+		d.pins[0].High()
+		d.pins[1].Low()
+		d.pins[2].High()
+		d.pins[3].Low()
+		break
+	case 1:
+		d.pins[0].Low()
+		d.pins[1].High()
+		d.pins[2].High()
+		d.pins[3].Low()
+		break
+	case 2:
+		d.pins[0].Low()
+		d.pins[1].High()
+		d.pins[2].Low()
+		d.pins[3].High()
+		break
+	case 3:
+		d.pins[0].High()
+		d.pins[1].Low()
+		d.pins[2].Low()
+		d.pins[3].High()
+		break
+	}
+}

examples/easystepper/main.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"machine"
+	"time"
+
+	"github.com/tinygo-org/drivers/easystepper"
+)
+
+func main() {
+	motor := easystepper.New(machine.P13, machine.P15, machine.P14, machine.P16, 200, 75)
+
+	for {
+		println("CLOCKWISE")
+		motor.Move(2050)
+		time.Sleep(time.Millisecond * 1000)
+
+		println("COUNTERCLOCKWISE")
+		motor.Move(-2050)
+		time.Sleep(time.Millisecond * 1000)
+	}
+}