MicroPython • controlling 4 28byj48 steppers from a rpi pico 2 w

Code:

# Programmable I/O example with 2 unipolar steppers 28BYJ-48 + UNL2003#  an Half Step sequence is used-  Sept 2021 - federicofrom machine import Pinfrom rp2 import PIO, StateMachine, asm_piofrom utime import sleep# ====== start Input DATA =======stepper_ratio = 1 / 64     # see stepper data sheetcog_nr = 8                 # see stepper data sheet# stepper motor- same colors sequence for pi pico BluePinkYellowOrange - ULN2003 BPYOstart_pin_0 = Pin(10)      # Stepper nr.1 - 1st ( Blue color) of 4 stepper's pinsstart_pin_1 = Pin(18)      # Stepper nr.2 - 1st ( Blue color) of 4 stepper's pinsnr_sm_pins = 4# sm  2 <= kHz <= 50 this trial with unipolar stepper 28BYJ-48frequency = 30_000         # default state machine frequencymin_frequency = 2_000      # from trialsmax_frequency = 50_000     # from trialsrev_angle = 360degrees = 360HALF_STEP = [9, 1, 3, 2, 6, 4, 12, 8]  # see forward_PIO() & backwards_PIO()nop_clock_delays = 32                  # see forward_PIO() & backwards_PIO()# ====== end  Input DATA =======steps_rev = int(cog_nr * len(HALF_STEP) * 1/stepper_ratio)# Run the state machine for sec_rev (360 degrees) secsec_rev = (1 / frequency) * 2 * nop_clock_delays * steps_revconstant = frequency * sec_rev # sm3.active(1);sleep(a * steps / steps_rev);sm3.active(0);sm3.exec("set(pins,0)")k_steps = rev_angle/steps_revsteps = int(degrees / k_steps)  # steps*k_steps = degree# ref: GET STARTED WITH MICROPYTHON ON RASPBERRY PI PICO#      Appendix C Programmable I/O# program definition - the @asm_pio descriptor tells MicroPython to treat# it as a PIO program and not a normal method# there are 4 set pins connected to the SM, and their initial state is set# when the StateMachine is created. # output low for all 4 pins ( 18,19, 20, 21)  - see sm0&sm1 instantiations for the 1st stepper# output low for all 4 pins ( 10,11, 12, 13)  - see sm2&sm3 instantiations for the 2nd stepper@asm_pio(set_init=(PIO.OUT_LOW,) * nr_sm_pins)  # method descriptordef forward_PIO():   # Half step 1&2 phases    # Step half a step to alternate between single coil and double coil steps.    HALF_STEP = [9, 1, 3, 2, 6, 4, 12, 8]    a = 31    wrap_target    # set() Drive stepper's pins as Half Step ON/OFF sequence and then delay for [a] cycles    set(pins, HALF_STEP[0])[a]    # nop is a pioasm pseudoinstruction used for extra delay    nop()[a]    set(pins, HALF_STEP[1])[a]    nop()[a]    set(pins, HALF_STEP[2])[a]    nop()[a]    set(pins, HALF_STEP[3])[a]    nop()[a]    set(pins, HALF_STEP[4])[a]    nop()[a]    set(pins, HALF_STEP[5])[a]    nop()[a]    set(pins, HALF_STEP[6])[a]    nop()[a]    set(pins, HALF_STEP[7])[a]    nop()[a]    wrap()@asm_pio(set_init=(PIO.OUT_LOW,) * nr_sm_pins)def backwards_PIO():    HALF_STEP = [8, 12, 4, 6, 2, 3, 1, 9]    a = 31    wrap_target()    set(pins, HALF_STEP[0])[a]    nop()[a]    set(pins, HALF_STEP[1])[a]    nop()[a]    set(pins, HALF_STEP[2])[a]    nop()[a]    set(pins, HALF_STEP[3])[a]    nop()[a]    set(pins, HALF_STEP[4])[a]    nop()[a]    set(pins, HALF_STEP[5])[a]    nop()[a]    set(pins, HALF_STEP[6])[a]    nop()[a]    set(pins, HALF_STEP[7])[a]    nop()[a]    wrap()# 1st steppersm0 = StateMachine(0,    forward_PIO, freq=frequency, set_base=start_pin_0)sm1 = StateMachine(1,  backwards_PIO, freq=frequency, set_base=start_pin_0)# 2nd steppersm2 = StateMachine(2,    forward_PIO, freq=frequency, set_base=start_pin_1)sm3 = StateMachine(3,  backwards_PIO, freq=frequency, set_base=start_pin_1)#-------------------------- END of Code------------------------------------#***** Run examples ******a = (constant / frequency)degrees = 360print("State Machine Hz = ", frequency, " ", a * degrees / rev_angle, " sec for ", degrees, " degrees")sm0.active(1)  # start the stepper nr1sm3.active(1)  # start the stepper nr3# Run the state machine for a * degrees / rev_angle secondssleep(a * degrees / rev_angle)sm0.active(0)  # stop the sm0 - 1st steppersm3.active(0)  # stop the sm3 - 2nd stepper# Turn off the set pins ( 4 pico/stepper pins) via an exec instruction.sm0.exec("set(pins,0)")sm3.exec("set(pins,0)")sleep(1)sm0.active(1); sleep(512 * constant/(frequency*steps_rev));sm0.active(0); sm0.exec("set(pins,0)")sm1.active(1); sleep(512 * constant/(frequency*steps_rev));sm1.active(0); sm1.exec("set(pins,0)")sm2.active(1); sleep(512 * constant/(frequency*steps_rev));sm2.active(0); sm2.exec("set(pins,0)")sm3.active(1); sleep(512 * constant/(frequency*steps_rev));sm3.active(0); sm3.exec("set(pins,0)")sm0.active(1); sleep(1024 * constant/(frequency*steps_rev));sm0.active(0); sm0.exec("set(pins,0)")sm1.active(1); sleep(1024 * constant/(frequency*steps_rev));sm1.active(0); sm1.exec("set(pins,0)")sm2.active(1); sleep(1024 * constant/(frequency*steps_rev));sm2.active(0); sm2.exec("set(pins,0)")sm3.active(1); sleep(1024 * constant/(frequency*steps_rev));sm3.active(0); sm3.exec("set(pins,0)")sm0.active(1); sleep(2048 * constant/(frequency*steps_rev));sm0.active(0); sm0.exec("set(pins,0)")sm1.active(1); sleep(2048 * constant/(frequency*steps_rev));sm1.active(0); sm1.exec("set(pins,0)")sm2.active(1); sleep(2048 * constant/(frequency*steps_rev));sm2.active(0); sm2.exec("set(pins,0)")sm3.active(1); sleep(2048 * constant/(frequency*steps_rev));sm3.active(0); sm3.exec("set(pins,0)")sm0.active(1); sm3.active(1); sleep(512 * constant/(frequency*steps_rev));sm0.active(0);sm3.active(0); sm0.exec("set(pins,0)"); sm3.exec("set(pins,0)")sm1.active(1); sm2.active(1); sleep(512 * constant/(frequency*steps_rev));sm1.active(0);sm2.active(0); sm1.exec("set(pins,0)"); sm2.exec("set(pins,0)")#---------------------------------------------------------------------------------------sleep(1)print( "to change the stepper speed we change the State Machine Hz with a new State Machine instantiation")frequency = 50000sec_rev = (1 / frequency) * 2 * nop_clock_delays * steps_revconstant = frequency * sec_rev a = (constant / frequency)degrees = 360sm1 = StateMachine(0,    forward_PIO, freq= frequency, set_base=start_pin_0)sm3 = StateMachine(3,    forward_PIO, freq= frequency, set_base=start_pin_1)print("State Machine Hz = ", frequency, " ", a * degrees / rev_angle, " sec for ", degrees, " degrees")sm1.active(1)  # start the stepper nr1sm3.active(1)  # start the stepper nr2# Run the state machine for a * degrees / rev_angle secondssleep(a * degrees / rev_angle)sm1.active(0)  # stop the sm1 - 1st steppersm3.active(0)  # stop the sm3 - 2nd stepper# Turn off the set pins ( 4 pico/stepper pins) via an exec instruction.sm1.exec("set(pins,0)")sm3.exec("set(pins,0)")sleep(1)print("********** 1st Stepper Forward ****************")sm0 = StateMachine(0,    forward_PIO, freq=frequency, set_base=start_pin_0)sm0.active(1);sleep(degrees * a  / rev_angle);sm0.active(0);sm0.exec("set(pins,0)")print("********** 1st Stepper Backward ****************")sm1 = StateMachine(1,  backwards_PIO, freq=frequency, set_base=start_pin_0)sm1.active(1);sleep(degrees * a  / rev_angle);sm1.active(0);sm1.exec("set(pins,0)")sleep(1)print("********** 2nd Stepper Forward ****************")sm2 = StateMachine(2,    forward_PIO, freq=frequency, set_base=start_pin_1)sm2.active(1);sleep(degrees * a  / rev_angle);sm2.active(0);sm2.exec("set(pins,0)")print("********** 2nd Stepper Backward ****************")sm3 = StateMachine(3,  backwards_PIO, freq=frequency, set_base=start_pin_1)sm3.active(1);sleep(degrees * a  / rev_angle);sm3.active(0);sm3.exec("set(pins,0)")print(" use of steps in place of degrees")sm3.active(1);sleep(2048 * a / steps_rev);sm3.active(0);sm3.exec("set(pins,0)")sleep(1)sm3.active(1);sleep(1024 * a  / steps_rev);sm3.active(0);sm3.exec("set(pins,0)")sleep(1)sm3.active(1);sleep(512 * a  / steps_rev);sm3.active(0);sm3.exec("set(pins,0)")sleep(1)sm3.active(1);sleep(512 * a  / steps_rev);sm3.active(0);sm3.exec("set(pins,0)")