diff options
| -rw-r--r-- | System_Python/encoder.py | 74 | ||||
| -rw-r--r-- | System_Python/test_Encoder.py | 64 |
2 files changed, 84 insertions, 54 deletions
diff --git a/System_Python/encoder.py b/System_Python/encoder.py new file mode 100644 index 0000000..b70fac6 --- /dev/null +++ b/System_Python/encoder.py @@ -0,0 +1,74 @@ +# Import required modules +import RPi.GPIO as GPIO +import time +import math + +# Constants: parameters that the caller cannot modify +# Delay: Minimum delay necessary after pull pin low to read input +delay = 0.0000005 + +# Encoder Class +# This controls the motor at the given IO +class Encoder: + def __init__(self, clk_pin, cs_pin, data_pin): + # Set the board IO (just in case it hasn't been done yet) + GPIO.setmode(GPIO.BCM) + # Setup class varaiable + self.offset=0 + self.clk_pin = clk_pin + self.cs_pin = cs_pin + self.data_pin = data_pin + # Setup the IO + try: + GPIO.setup(self.clk_pin,GPIO.OUT) + GPIO.setup(self.cs_pin,GPIO.OUT) + GPIO.setup(self.data_pin,GPIO.IN) + # Setup the CS and CLK to be high + GPIO.output(PIN_CLK,1) + GPIO.output(PIN_CS,1) + except: + print("ERROR. Unable to setup the configuration required") + # Wait some time to before reading + time.sleep(0.5) + def setZero(self): + # Take current position as zero + self.offset=self.readPosition('Raw') + def clockup(self): + GPIO.output(self.clk_pin,1) + def clockdown(self): + GPIO.output(self.clk_pin,0) + def readPosition(self, format): + # Most of this is based of timing diagram of encoder + # Pull CS low to start reading + GPIO.output(self.cs_pin,0) + # Delay necessary before reading is ready + time.sleep(delay*2) + data = 0 + # Clockdown necessary before reading + self.clockdown() + # Go through 10 bits needed to read + for i in range(0,10): + # Clock up to start reading one bit + self.clockup() + # Shift data left and insert input + data<<=1 + data|=GPIO.input(self.data_pin) + # Clock down after finish reading + self.clockdown() + # Pull CS high after finish reading + GPIO.output(self.cs_pin,1) + # Format with offset, Max is 1024 + data=(data+offset)%1024 + # Data is linearly mapped + if format=="Raw": + return data + elif format=="Degrees": + degrees=data/(1024/360) + return degrees + elif format=="Radian": + radians=data/(1024/(2*math.pi)) + return radians + else: + print("ERROR. Invalid format (Raw, Degrees, Radians)") + return None + diff --git a/System_Python/test_Encoder.py b/System_Python/test_Encoder.py index ab74c6e..08804fa 100644 --- a/System_Python/test_Encoder.py +++ b/System_Python/test_Encoder.py @@ -1,58 +1,14 @@ +from encoder import Encoder import time -import RPi.GPIO as GPIO -GPIO.setmode(GPIO.BCM) +# Decide which pins to hook up to on the Pi before running +clk_pin = 2 +cs_pin = 4 +data_pin = 3 -PIN_CLK = 2 -PIN_DATA = 3 -PIN_CS = 4 -delay = 0.0000005 +e = Encoder(clk_pin, cs_pin, data_pin) +e.setZero() -# pin setup done here -try: - GPIO.setup(PIN_CLK,GPIO.OUT) - GPIO.setup(PIN_DATA,GPIO.IN) - GPIO.setup(PIN_CS,GPIO.OUT) - GPIO.output(PIN_CS,1) - GPIO.output(PIN_CLK,1) -except: - print("ERROR. Unable to setup the configuration requested") - -#wait some time to start -time.sleep(0.5) - -print("GPIO configuration enabled") - -def clockup(): - GPIO.output(PIN_CLK,1) -def clockdown(): - GPIO.output(PIN_CLK,0) - -def readpos(): - GPIO.output(PIN_CS,0) #pulls low to start - - time.sleep(delay*2) - data = 0 - clockdown() - - time1=time.clock() - for i in range(0,10): #bitcount): - clockup() #375 ns between each - data<<=1 - data|=GPIO.input(PIN_DATA) - #while(time.clock()-time1<minReadValue); - clockdown() - print(time.clock()-time1) - GPIO.output(PIN_CS,1) #pull high after finish - - return data - -try: - while(1): - print(readpos()) - time.sleep(0.001) - #break - -finally: - print("cleaning up GPIO") - GPIO.cleanup()
\ No newline at end of file +while(1): + print(e.readPosition('Degrees')) + time.sleep(0.001)
\ No newline at end of file |