036 - MicroPython TechNotes: Stepper Motor

 1# More details can be found in TechToTinker.blogspot.com 
 2# George Bantique | tech.to.tinker@gmail.com
 3
 4from machine import Pin
 5from time import sleep_ms
 6from time import sleep_us
 7
 8
 9def map(x, in_min, in_max, out_min, out_max): 
10    return int((x - in_min) * (out_max - out_min) /
11               (in_max - in_min) + out_min)
12    
13class GORILLACELL_STEPMOTOR:
14    def __init__(self, step_pin, dir_pin):
15        self.step = Pin(step_pin, Pin.OUT)
16        self.dir = Pin(dir_pin, Pin.OUT)
17
18    def rotate(self, angle=0, rotation='cw'):
19        num_of_steps = map(angle, 0, 360, 0, 200)
20        if rotation=='cw':
21            self.dir.value(0)
22            for i in range(0,num_of_steps,1):
23               self.step.value(1)
24               sleep_us(500)
25               self.step.value(0)
26               sleep_us(500)
27        if rotation=='ccw':
28            self.dir.value(1)
29            for i in range(num_of_steps-1,-1,-1):
30               self.step.value(1)
31               sleep_us(500)
32               self.step.value(0)
33               sleep_us(500)       
34
35stepper = GORILLACELL_STEPMOTOR(step_pin=19, dir_pin=18)
36
37
38# The following lines of codes can be tested using the REPL:
39# 1. To rotate the stepper motor in clockwise direction:
40# stepper.rotate(360, 'cw')
41# The first parameter, sets the angle of rotation
42# The second parameter, sets the direction
43# 2. To rotate it in counter clockwise direction:
44# stepper.rotate(360, 'ccw')

  1# More details can be found in TechToTinker.blogspot.com 
  2# George Bantique | tech.to.tinker@gmail.com
  3
  4from machine import Pin
  5from time import ticks_ms
  6from time import sleep_ms
  7from time import sleep_us
  8from machine import SoftI2C
  9from i2c_lcd import I2cLcd
 10from rotary_irq import RotaryIRQ
 11
 12
 13def map(x, in_min, in_max, out_min, out_max): 
 14    return int((x - in_min) * (out_max - out_min) /
 15               (in_max - in_min) + out_min)
 16    
 17class GORILLACELL_STEPMOTOR:
 18    def __init__(self, step_pin, dir_pin):
 19        self.step = Pin(step_pin, Pin.OUT)
 20        self.dir = Pin(dir_pin, Pin.OUT)
 21
 22    def rotate(self, angle=0, rotation='cw'):
 23        num_of_steps = map(angle, 0, 360, 0, 200)
 24        if rotation=='cw':
 25            self.dir.value(0)
 26            for i in range(0,num_of_steps,1):
 27               self.step.value(1)
 28               sleep_us(500)
 29               self.step.value(0)
 30               sleep_us(500)
 31        if rotation=='ccw':
 32            self.dir.value(1)
 33            for i in range(num_of_steps-1,-1,-1):
 34               self.step.value(1)
 35               sleep_us(500)
 36               self.step.value(0)
 37               sleep_us(500)       
 38
 39led = Pin(2, Pin.OUT)
 40stepper = GORILLACELL_STEPMOTOR(step_pin=19, dir_pin=18)
 41i2c = SoftI2C(scl=Pin(22), sda=Pin(21), freq=400000) 
 42lcd = I2cLcd(i2c, 0x20, 2, 16)
 43r = RotaryIRQ(pin_num_clk=32, 
 44              pin_num_dt=33, 
 45              min_val=0, 
 46              max_val=19, 
 47              reverse=True, 
 48              range_mode=RotaryIRQ.RANGE_WRAP)
 49rsw = Pin(34, Pin.IN)              
 50val_old = r.value()
 51isRotaryEncoder = False
 52isPress = False
 53working_idx = 0 # holds the menu index
 54curr_direction = 0 # 0-cw, 1-ccw
 55curr_angle = 360
 56curr_action = 0 # 0-do not execute, 1-execute
 57
 58# get the current time
 59prev_time = ticks_ms()
 60
 61menus = ['Edit Direction',
 62         'Edit Angle',
 63         'Set, Move!',
 64         'Freestyle']
 65
 66# Prints a string of characters in the LCD
 67#    text - the string you want to print
 68#    x - x position
 69#    y - y position
 70def print_line(text, x, y):
 71    # Calculate the start of character display
 72    start = 8-len(text)//2
 73    # Calculate the end of character display
 74    end = start + len(text)
 75    
 76    # Clears characters before the start position
 77    lcd.move_to(x,y)
 78    for i in range(x,start,1):
 79        lcd.putchar(' ')
 80    
 81    # Clears characters after the end position
 82    lcd.move_to(end,y)
 83    for i in range(end,15,1):
 84        lcd.putchar(' ')
 85    
 86    # Print the desired display
 87    lcd.move_to(start,y)
 88    lcd.putstr(text)
 89    
 90# Performs updating the menu display
 91# according to the rotary encoder value
 92def process_menu(rotary_dir=0):
 93    # Global variables here if needed to be edited,
 94    # else, no need to declare as global here.
 95    global working_idx
 96    global curr_direction
 97    global curr_angle
 98    global curr_action
 99
100    
101    # If the rotary value is less than -1 ie:-2,-3,etc:
102    #    rotary value = -1
103    # If the rotary value is more than 1:
104    #    rotary value = 1
105    # Else
106    #    rotary value is not modified
107    if rotary_dir < -1:
108        rotary_dir = -1
109    elif rotary_dir > 1:
110        rotary_dir = 1
111    
112    # DISPLAY ONLY MODE
113    if isPress==False:
114        # Calculate the working index
115        # based on rotary encoder value.
116        working_idx += rotary_dir
117        if working_idx < 0:
118            working_idx = 0
119        elif working_idx > len(menus) - 1:
120            working_idx = len(menus) - 1
121
122        # Check if there is menu available in left
123        # If true, display < character
124        # If false, display none
125        lcd.move_to(0,0)
126        if working_idx==0:
127            lcd.putchar(' ')
128        else:
129            lcd.putchar('<')
130
131        # Print the menu based on working index value
132        print_line(menus[working_idx],1,0)
133        
134        # Checks if there is menu available in right
135        # If true, display > character
136        # If false, display none
137        lcd.move_to(15,0)
138        if working_idx==len(menus)-1:
139            lcd.putchar(' ')
140        else:
141            lcd.putchar('>')
142        
143        # ------------------------
144        # Process menu selections:
145        if working_idx==0:
146            # Display current direction
147            curr_dir = ""
148            if curr_direction==0:
149                curr_dir = "Clockwise"
150            else: # curr_direction==1:
151                curr_dir = "Anti-clockwise"
152            print_line(curr_dir,1,1)
153        elif working_idx==1:
154            # Display current angle
155            print_line(str(curr_angle),1,1)
156        elif working_idx==2:
157            curr_act = ""
158            if curr_action==0:
159                curr_act = "Status: Stop"
160            else:
161                curr_act = "Status: Go"
162            print_line(curr_act,1,1)
163        elif working_idx==3:
164            print_line("Press it",1,1)
165        else:
166            print('where is this?')
167    # CONFIGURATION MODE
168    elif isPress==True:
169        if working_idx==0:
170            # Edit Direction
171            if rotary_dir!=0:
172                curr_direction = not curr_direction
173            curr_dir = ""
174            if curr_direction==0:
175                curr_dir = "Clockwise"
176            else: # curr_direction==1:
177                curr_dir = "Anti-clockwise"
178            print_line(curr_dir,1,1)
179        elif working_idx==1:
180            # Display current angle
181            if rotary_dir!=0:
182                curr_angle+=rotary_dir
183            print_line(str(curr_angle),1,1) 
184        elif working_idx==2:
185            if rotary_dir!=0:
186                curr_action = not curr_action
187            curr_act = ""
188            if curr_action==0:
189                curr_act = "Status: Stop"
190            else:
191                curr_act = "Status: Go"
192            print_line(curr_act,1,1)
193        elif working_idx==3:
194            if rotary_dir < 0:
195                stepper.rotate(rotary_dir * -10, 'ccw')
196            elif rotary_dir > 0:
197                stepper.rotate(rotary_dir * 10, 'cw')  
198        else:
199            print('where is this?')
200# Prints the initial menus
201process_menu()
202
203while True:
204    if curr_action==1 and isSaved==True: # status: go
205        curr_dir = ""
206        if curr_direction==0: # cw
207            curr_dir = "cw"
208        else:
209            curr_dir = "ccw"
210        stepper.rotate(curr_angle, curr_dir)
211        curr_action=0 # status: stop
212        process_menu()    
213    
214    # Creates 200 ms interval
215    if ticks_ms() - prev_time  >= 200:
216        # Checks only for the switch when index is more than 2
217        # If switch is press, toggle the state of isPress variable
218        # If isPress is True, config for editing
219        # If isPress is False back again, save the configs.
220        if rsw.value()==1:
221            isPress = not isPress
222
223            if isPress==True:
224                process_menu()
225                isSaved=False
226            if isPress==False and isSaved==False:
227                isSaved=True
228        
229        # Read the rotary encoder values for processing
230        val_new = r.value()
231        if val_old != val_new:
232            if val_old == 0 and val_new == 19:
233                val_dif = -1
234            elif val_old == 19 and val_new == 0:
235                val_dif = 1
236            else:
237                val_dif = val_new - val_old
238            print(val_dif)
239            process_menu(val_dif)
240            val_old = val_new
241        
242        # Blink the onboard LED during config mode
243        if isPress:
244            led.value(not led.value())
245        else:
246            led.value(0)
247        
248        # Save the current timer counter
249        prev_time = ticks_ms()