Robotics-at-Home-with-Raspb.../ch-6/3-change-conditions/pio_two_encoders_when_changed.py
2022-03-20 22:27:49 +00:00

52 lines
1.3 KiB
Python

"""Send this code, run and watch the repl.
Then turn the wheel slowly to see the change"""
import board
import rp2pio
import adafruit_pioasm
import array
program = """
.program pio_input
set y, 0 ; clear y
read:
mov x, y ; store old Y in x
in null, 31 ; Clear ISR
in pins, 2 ; read in two pins (into ISR)
mov y, isr ; store ISR in y
jmp x!=y different ; Jump if its different
jmp read ; otherwise loop back to read
different:
push noblock ; put ISR into input FIFO
jmp read ; loop back
"""
assembled = adafruit_pioasm.assemble(program)
## set up a statemachine
left_enc = rp2pio.StateMachine(
assembled, frequency=0, first_in_pin=board.GP20, in_pin_count=2
)
right_enc = rp2pio.StateMachine(
assembled, frequency=0, first_in_pin=board.GP26, in_pin_count=2
)
buffer = array.array("I", [0])
left_data = 0
right_data = 0
while True:
# read data from the fifo
if left_enc.in_waiting:
left_enc.readinto(buffer)
left_data = buffer[0]
# print it.
print("{:08b} {:08b}".format(left_data, right_data))
if right_enc.in_waiting:
right_enc.readinto(buffer)
right_data = buffer[0]
# print it.
print("{:08b} {:08b}".format(left_data, right_data))