Tag Archives: State Machine

In this video lesson we show how neopixels work at a fundamental level, and show how you can use the Raspberry Pi Pico State Machines to control the neoixels. Neopixels are an excellent example for showing the importance of the pico state machine. The neopixels demand precise timing and sequence of bits to operate properly, and that precision can not be achieved in python. The video explains how the State Machines can be programmed to control the neopixels.

For your convenience, the code is included below.

import rp2
from machine import Pin
import time
@rp2.asm_pio(sideset_init=rp2.PIO.OUT_HIGH,
             out_shiftdir=rp2.PIO.SHIFT_LEFT,
             autopull=True,
             pull_thresh=24)
def ws2812():
    wrap_target()
    label("bitloop")
    out(x,1).side(0)
    jmp(not_x,"do_zero").side(1)
    nop().side(1)[5-1]
    nop().side(0)[2-1]
    jmp("bitloop").side(0)
    label("do_zero")
    nop().side(1)[2-1]
    jmp("bitloop").side(0)[6-1]
    wrap()
sm=rp2.StateMachine(0,ws2812,freq=8000000,sideset_base=Pin(0))
sm.active(1)

def write_neopixel(colors):
    for color in colors:
        grb=color[1]<<16 | color[0]<<8 | color[2]
        sm.put(grb,8)
        
    
NUM_LEDS =8
myColor=[0]*NUM_LEDS
myColor=[[100,0,0],
         [0,100,0],
         [0,0,100],
         [0,100,100],
         [100,0,100],
         [100,100,0],
         [200,100,0],
         [255,255,255]]
write_neopixel(myColor)

import rp2

from machine import Pin

import time

@rp2.asm_pio(sideset_init=rp2.PIO.OUT_HIGH,

out_shiftdir=rp2.PIO.SHIFT_LEFT,

autopull=True,

pull_thresh=24)

def ws2812():

wrap_target()

label("bitloop")

out(x,1).side(0)

jmp(not_x,"do_zero").side(1)

nop().side(1)[5-1]

nop().side(0)[2-1]

jmp("bitloop").side(0)

label("do_zero")

nop().side(1)[2-1]

jmp("bitloop").side(0)[6-1]

wrap()

sm=rp2.StateMachine(0,ws2812,freq=8000000,sideset_base=Pin(0))

sm.active(1)

def write_neopixel(colors):

for color in colors:

grb=color[1]<<16 | color[0]<<8 | color[2]

sm.put(grb,8)

NUM_LEDS =8

myColor=[0]*NUM_LEDS

myColor=[[100,0,0],

[0,100,0],

[0,0,100],

[0,100,100],

[100,0,100],

[100,100,0],

[200,100,0],

[255,255,255]]

write_neopixel(myColor)

MicroPython, Raspberry Pi Pico

Control Raspberry Pi Pico PIO State Machines in a Micropython Class

December 24, 2024 admin

In this video lesson we show how you can control a PIO State Machine on the Raspberry Pi Pico W inside of a micropython class. We demonstrate with the practical example of controlling servos with a servo Class which we create. The objective is to ‘hide’ all the complex code in the class, allowing less adept users to interact with the servo with simple python commands. For your convenience the code developed in this video is included below. Enjoy!

import time
from machine import Pin
import rp2
class servoState:
    counter=0
    @rp2.asm_pio(set_init=rp2.PIO.OUT_LOW,out_shiftdir=rp2.PIO.SHIFT_RIGHT)
    def servoSet():
        wrap_target()
        mov(x,osr)
        mov(y,isr)
        set(pins,0)
        label('timeLoop')
        jmp(x_not_y,'nxt')
        set(pins,1)
        label('nxt')
        jmp(y_dec,'timeLoop')    
        wrap()
    
    def __init__(self,servoPin):
        self.sm = rp2.StateMachine(servoState.counter,servoState.servoSet, freq=2000000, set_base=Pin(servoPin))
        self.sm.active(1)
        self.sm.put(20000)
        self.sm.exec("pull()")
        self.sm.exec("mov(isr,osr)")
        print("State Machine: "+str(servoState.counter)+" created")
        servoState.counter=servoState.counter+1
    def servoAngle(self,angle):
        pw=int(500+angle*2000/180)
        self.sm.put(pw)
        self.sm.exec("pull()")
myServo1=servoState(20)
myServo2=servoState(21)
myServo3=servoState(22)
myServo4=servoState(23)
myServo5=servoState(24)
myServo6=servoState(25)
myServo7=servoState(26)
myServo8=servoState(27)
while True:
    for angle in range(0,180,1):
        myServo1.servoAngle(angle)
        myServo7.servoAngle(180-angle)
    time.sleep(5)
    for angle in range(180,0,-1):
        myServo1.servoAngle(angle)
        myServo7.servoAngle(180-angle)
    time.sleep(5)

import time

from machine import Pin

import rp2

class servoState:

counter=0

@rp2.asm_pio(set_init=rp2.PIO.OUT_LOW,out_shiftdir=rp2.PIO.SHIFT_RIGHT)

def servoSet():

wrap_target()

mov(x,osr)

mov(y,isr)

set(pins,0)

label('timeLoop')

jmp(x_not_y,'nxt')

set(pins,1)

label('nxt')

jmp(y_dec,'timeLoop')

wrap()

def __init__(self,servoPin):

self.sm = rp2.StateMachine(servoState.counter,servoState.servoSet, freq=2000000, set_base=Pin(servoPin))

self.sm.active(1)

self.sm.put(20000)

self.sm.exec("pull()")

self.sm.exec("mov(isr,osr)")

print("State Machine: "+str(servoState.counter)+" created")

servoState.counter=servoState.counter+1

def servoAngle(self,angle):

pw=int(500+angle*2000/180)

self.sm.put(pw)

self.sm.exec("pull()")

myServo1=servoState(20)

myServo2=servoState(21)

myServo3=servoState(22)

myServo4=servoState(23)

myServo5=servoState(24)

myServo6=servoState(25)

myServo7=servoState(26)

myServo8=servoState(27)

while True:

for angle in range(0,180,1):

myServo1.servoAngle(angle)

myServo7.servoAngle(180-angle)

time.sleep(5)

for angle in range(180,0,-1):

myServo1.servoAngle(angle)

myServo7.servoAngle(180-angle)

time.sleep(5)

MicroPython, Raspberry Pi Pico

Sweeping Servo Position Using the PIO State Machine on the Raspberry Pi Pico PIO State Machine

December 10, 2024 admin

In this video lesson we show how you can use the Raspberry Pi Pico PIO State Machine to sweep a servo through its full range of motion. The video will take you through things step-by-step. For your convenience the code developed in the video is included below. Enjoy!

import time
from machine import Pin
import rp2
@rp2.asm_pio(set_init=rp2.PIO.OUT_LOW,out_shiftdir=rp2.PIO.SHIFT_RIGHT)
def servoSet():
    wrap_target()
    mov(x,osr)
    mov(y,isr)
    set(pins,0)
    label('timeLoop')
    jmp(x_not_y,'nxt')
    set(pins,1)
    label('nxt')
    jmp(y_dec,'timeLoop')    
    wrap()  
sm0 = rp2.StateMachine(0,servoSet, freq=2000000, set_base=Pin(20))
sm0.active(1)
sm0.put(20000)
sm0.exec("pull()")
sm0.exec("mov(isr,osr)")
while True:
    for angle in range(0,180,1):
        pw=int(500+angle*2000/180)
        sm0.put(pw)
        sm0.exec("pull()")
    time.sleep(5)
    for angle in range(180,0,-1):
        pw=int(500+angle*2000/180)
        sm0.put(pw)
        sm0.exec("pull()")

import time

from machine import Pin

import rp2

@rp2.asm_pio(set_init=rp2.PIO.OUT_LOW,out_shiftdir=rp2.PIO.SHIFT_RIGHT)

def servoSet():

wrap_target()

mov(x,osr)

mov(y,isr)

set(pins,0)

label('timeLoop')

jmp(x_not_y,'nxt')

set(pins,1)

label('nxt')

jmp(y_dec,'timeLoop')

wrap()

sm0 = rp2.StateMachine(0,servoSet, freq=2000000, set_base=Pin(20))

sm0.active(1)

sm0.put(20000)

sm0.exec("pull()")

sm0.exec("mov(isr,osr)")

while True:

for angle in range(0,180,1):

pw=int(500+angle*2000/180)

sm0.put(pw)

sm0.exec("pull()")

time.sleep(5)

for angle in range(180,0,-1):

pw=int(500+angle*2000/180)

sm0.put(pw)

sm0.exec("pull()")

Technology Tutorials

Tag Archives: State Machine

Controlling NeoPixel Array on PIO State Machine on Raspberry Pi Pico

Control Raspberry Pi Pico PIO State Machines in a Micropython Class

Sweeping Servo Position Using the PIO State Machine on the Raspberry Pi Pico PIO State Machine

Making The World a Better Place One High Tech Project at a Time. Enjoy!