hybridgroup.gobot/drivers/gpio/easy_driver.go

282 lines
6.5 KiB
Go

package gpio
import (
"errors"
"strconv"
"time"
"gobot.io/x/gobot"
)
// EasyDriver object
type EasyDriver struct {
gobot.Commander
name string
connection DigitalWriter
stepPin string
dirPin string
enPin string
sleepPin string
angle float32
rpm uint
dir int8
moving bool
stepNum int
enabled bool
sleeping bool
}
// NewEasyDriver returns a new EasyDriver from SparkFun (https://www.sparkfun.com/products/12779)
// TODO: Support selecting phase input instead of hard-wiring MS1 and MS2 to board truth table
// This should also work for the BigEasyDriver (untested)
// A - DigitalWriter
// stepPin - Pin corresponding to step input on EasyDriver
// dirPin - Pin corresponding to dir input on EasyDriver. Optional
// enPin - Pin corresponding to enabled input on EasyDriver. Optional
// sleepPin - Pin corresponding to sleep input on EasyDriver. Optional
// angle - Step angle of motor
func NewEasyDriver(a DigitalWriter, angle float32, stepPin string, dirPin string, enPin string, sleepPin string) *EasyDriver {
d := &EasyDriver{
Commander: gobot.NewCommander(),
name: gobot.DefaultName("EasyDriver"),
connection: a,
stepPin: stepPin,
dirPin: dirPin,
enPin: enPin,
sleepPin: sleepPin,
angle: angle,
rpm: 1,
dir: 1,
enabled: true,
sleeping: false,
}
// panic if step pin isn't set
if stepPin == "" {
panic("Step pin is not set")
}
// 1/4 of max speed. Not too fast, not too slow
d.rpm = d.GetMaxSpeed() / 4
d.AddCommand("Move", func(params map[string]interface{}) interface{} {
degs, _ := strconv.Atoi(params["degs"].(string))
return d.Move(degs)
})
d.AddCommand("Step", func(params map[string]interface{}) interface{} {
return d.Step()
})
d.AddCommand("Run", func(params map[string]interface{}) interface{} {
return d.Run()
})
d.AddCommand("Stop", func(params map[string]interface{}) interface{} {
return d.Stop()
})
return d
}
// Name of EasyDriver
func (d *EasyDriver) Name() string { return d.name }
// SetName sets name for EasyDriver
func (d *EasyDriver) SetName(n string) { d.name = n }
// Connection returns EasyDriver's connection
func (d *EasyDriver) Connection() gobot.Connection { return d.connection.(gobot.Connection) }
// Start implements the Driver interface
func (d *EasyDriver) Start() (err error) { return }
// Halt implements the Driver interface; stops running the stepper
func (d *EasyDriver) Halt() (err error) {
d.Stop()
return
}
// Move the motor given number of degrees at current speed.
func (d *EasyDriver) Move(degs int) (err error) {
if d.moving {
// don't do anything if already moving
return
}
d.moving = true
steps := int(float32(degs) / d.angle)
for i := 0; i < steps; i++ {
if !d.moving {
// don't continue to step if driver is stopped
break
}
d.Step()
}
d.moving = false
return
}
// Step the stepper 1 step
func (d *EasyDriver) Step() (err error) {
stepsPerRev := d.GetMaxSpeed()
// a valid steps occurs for a low to high transition
d.connection.DigitalWrite(d.stepPin, 0)
// 1 minute / steps per revolution / revolutions per minute
// let's keep it as Microseconds so we only have to do integer math
time.Sleep(time.Duration(60*1000*1000/stepsPerRev/d.rpm) * time.Microsecond)
d.connection.DigitalWrite(d.stepPin, 1)
// increment or decrement the number of steps by 1
d.stepNum += int(d.dir)
return
}
// Run the stepper continuously
func (d *EasyDriver) Run() (err error) {
if d.moving {
// don't do anything if already moving
return
}
d.moving = true
go func() {
for d.moving {
d.Step()
}
}()
return
}
// Stop running the stepper
func (d *EasyDriver) Stop() (err error) {
d.moving = false
return
}
// SetDirection sets the direction to be moving. Valid directions are "cw" or "ccw"
func (d *EasyDriver) SetDirection(dir string) (err error) {
// can't change direct if dirPin isn't set
if d.dirPin == "" {
return errors.New("dirPin is not set")
}
if dir == "ccw" {
d.dir = -1
d.connection.DigitalWrite(d.dirPin, 1) // high is ccw
} else { // default to cw, even if user specified wrong value
d.dir = 1
d.connection.DigitalWrite(d.dirPin, 0) // low is cw
}
return
}
// SetSpeed sets the speed of the motor in RPMs. 1 is the lowest and GetMaxSpeed is the highest
func (d *EasyDriver) SetSpeed(rpm uint) (err error) {
if rpm < 1 {
d.rpm = 1
} else if rpm > d.GetMaxSpeed() {
d.rpm = d.GetMaxSpeed()
} else {
d.rpm = rpm
}
return
}
// GetMaxSpeed returns the max speed of the stepper
func (d *EasyDriver) GetMaxSpeed() uint {
return uint(360 / d.angle)
}
// GetCurrentStep returns current step number
func (d *EasyDriver) GetCurrentStep() int {
return d.stepNum
}
// IsMoving returns a bool stating whether motor is currently in motion
func (d *EasyDriver) IsMoving() bool {
return d.moving
}
// Enable enables all motor output
func (d *EasyDriver) Enable() (err error) {
// can't enable if enPin isn't set. This is fine normally since it will be enabled by default
if d.enPin == "" {
return errors.New("enPin is not set. Board is enabled by default")
}
d.enabled = true
d.connection.DigitalWrite(d.enPin, 0) // enPin is active low
return
}
// Disable disables all motor output
func (d *EasyDriver) Disable() (err error) {
// can't disable if enPin isn't set
if d.enPin == "" {
return errors.New("enPin is not set")
}
// let's stop the motor first
d.Stop()
d.enabled = false
d.connection.DigitalWrite(d.enPin, 1) // enPin is active low
return
}
// IsEnabled returns a bool stating whether motor is enabled
func (d *EasyDriver) IsEnabled() bool {
return d.enabled
}
// Sleep puts the driver to sleep and disables all motor output. Low power mode.
func (d *EasyDriver) Sleep() (err error) {
// can't sleep if sleepPin isn't set
if d.sleepPin == "" {
return errors.New("sleepPin is not set")
}
// let's stop the motor first
d.Stop()
d.sleeping = true
d.connection.DigitalWrite(d.sleepPin, 0) // sleepPin is active low
return
}
// Wake wakes up the driver
func (d *EasyDriver) Wake() (err error) {
// can't wake if sleepPin isn't set
if d.sleepPin == "" {
return errors.New("sleepPin is not set")
}
d.sleeping = false
d.connection.DigitalWrite(d.sleepPin, 1) // sleepPin is active low
// we need to wait 1ms after sleeping before doing a step to charge the step pump (according to data sheet)
// this will ensure that happens
time.Sleep(1 * time.Millisecond)
return
}
// IsSleeping returns a bool stating whether motor is enabled
func (d *EasyDriver) IsSleeping() bool {
return d.sleeping
}