Rev Author Line No. Line
4305 kaklik 1 #!/usr/bin/python
2 # -------------------------------------------
3 # HBSTEP01A Stepper Motor control Example
4 # -------------------------------------------
5  
6 #uncomment for debbug purposes
7 #import logging
8 #logging.basicConfig(level=logging.DEBUG)
9  
10 import sys
11 import time
12 from pymlab import config
13  
14  
15 class axis:
16 def __init__(self, SPI_CS, Direction, StepsPerUnit):
17 ' One axis of robot '
18 self.CS = SPI_CS
19 self.Dir = Direction
20 self.SPU = StepsPerUnit
21 self.Reset()
22  
23 def Reset(self):
24 ' Reset Axis and set default parameters for H-bridge '
25 spi.SPI_write_byte(self.CS, 0xC0) # reset
26 # spi.SPI_write_byte(self.CS, 0x14) # Stall Treshold setup
27 # spi.SPI_write_byte(self.CS, 0xFF)
28 # spi.SPI_write_byte(self.CS, 0x13) # Over Current Treshold setup
29 # spi.SPI_write_byte(self.CS, 0xFF)
30 #spi.SPI_write_byte(self.CS, 0x15) # Full Step speed
31 #spi.SPI_write_byte(self.CS, 0x00)
32 #spi.SPI_write_byte(self.CS, 0x30)
33 #spi.SPI_write_byte(self.CS, 0x0A) # KVAL_RUN
34 #spi.SPI_write_byte(self.CS, 0x50)
35 spi.SPI_write_byte(self.CS, 0x18) # KVAL_RUN
36 spi.SPI_write_byte(self.CS, 0b11000000)
37 spi.SPI_write_byte(self.CS, 0x88)
38  
39 def MaxSpeed(self, speed):
40 ' Setup of maximum speed '
41 spi.SPI_write_byte(self.CS, 0x07) # Max Speed setup
42 spi.SPI_write_byte(self.CS, 0x00)
43 spi.SPI_write_byte(self.CS, speed)
44  
45 def ReleaseSW(self):
46 ' Go away from Limit Switch '
47 while self.ReadStatusBit(2) == 1: # is Limit Switch ON ?
48 spi.SPI_write_byte(self.CS, 0x92 | (~self.Dir & 1)) # release SW
49 while self.IsBusy():
50 pass
51 self.MoveWait(10) # move 10 units away
52  
53 def GoZero(self, speed):
54 ' Go to Zero position '
55 self.ReleaseSW()
56  
57 spi.SPI_write_byte(self.CS, 0x82 | (self.Dir & 1)) # Go to Zero
58 spi.SPI_write_byte(self.CS, 0x00)
59 spi.SPI_write_byte(self.CS, speed)
60 while self.IsBusy():
61 pass
62 time.sleep(0.3)
63 self.ReleaseSW()
64  
65 def Move(self, units):
66 ' Move some distance units from current position '
67 steps = units * self.SPU # translate units to steps
68 if steps > 0: # look for direction
69 spi.SPI_write_byte(self.CS, 0x40 | (~self.Dir & 1))
70 else:
71 spi.SPI_write_byte(self.CS, 0x40 | (self.Dir & 1))
72 steps = int(abs(steps))
73 spi.SPI_write_byte(self.CS, (steps >> 16) & 0xFF)
74 spi.SPI_write_byte(self.CS, (steps >> 8) & 0xFF)
75 spi.SPI_write_byte(self.CS, steps & 0xFF)
76  
77 def MoveWait(self, units):
78 ' Move some distance units from current position and wait for execution '
79 self.Move(units)
80 while self.IsBusy():
81 pass
82  
83 def Float(self):
84 ' switch H-bridge to High impedance state '
85 spi.SPI_write_byte(self.CS, 0xA0)
86  
87 def ReadStatusBit(self, bit):
88 ' Report given status bit '
89 spi.SPI_write_byte(self.CS, 0x39) # Read from address 0x19 (STATUS)
90 spi.SPI_write_byte(self.CS, 0x00)
91 data0 = spi.SPI_read_byte() # 1st byte
92 spi.SPI_write_byte(self.CS, 0x00)
93 data1 = spi.SPI_read_byte() # 2nd byte
94 #print hex(data0), hex(data1)
95 if bit > 7: # extract requested bit
96 OutputBit = (data0 >> (bit - 8)) & 1
97 else:
98 OutputBit = (data1 >> bit) & 1
99 return OutputBit
100  
101  
102 def IsBusy(self):
103 """ Return True if tehre are motion """
104 if self.ReadStatusBit(1) == 1:
105 return False
106 else:
107 return True
108  
109 # End Class axis --------------------------------------------------
110  
111  
112  
113 cfg = config.Config(
114 i2c = {
115 "port": 1,
116 },
117  
118 bus = [
119 {
120 "type": "i2chub",
121 "address": 0x70,
122 "children": [
123 { "name":"spi", "type":"i2cspi", "channel": 1, },
124 ],
125 },
126 ],
127 )
128  
129  
130 cfg.initialize()
131  
132 print "Stepper motor control example. \r\n"
133  
134 spi = cfg.get_device("spi")
135  
136 spi.route()
137  
138 try:
139 print "SPI configuration.."
140 spi.SPI_config(spi.I2CSPI_MSB_FIRST| spi.I2CSPI_MODE_CLK_IDLE_HIGH_DATA_EDGE_TRAILING| spi.I2CSPI_CLK_461kHz)
141 time.sleep(1)
142  
143 print "Axis inicialization"
144 X = axis(spi.I2CSPI_SS0, 0, 641) # set Number of Steps per axis Unit and set Direction of Rotation
145 X.MaxSpeed(2) # set maximal motor speed
146  
147 print "Axis is running"
148  
149 for i in range(5):
150 X.MoveWait(50) # move 50 unit forward and wait for motor stop
151 time.sleep(0.5)
152 X.MoveWait(-50) # move 50 unit backward and wait for motor stop
153 time.sleep(0.5)
154  
155 X.Float() # release power
156  
157  
158 finally:
159 print "stop"