Pwm - Raspberry Pi Pico Python SDK Manual

Raspberry Pi Pico Python SDK
programmable frame size
18 in_(pins, 1)
19 jmp(not_osre, "bitloop") .side(0x1)
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21 nop()
22 wrap()
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25 class
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27 def
=1000000):
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pin_sck), out_base=Pin(pin_mosi), in_base=Pin(pin_sck))
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32 # Note this code will die spectacularly cause we're not draining the RX FIFO
33 def
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37 def
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43 def
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
NOTE
This SPI program supports programmable frame sizes (by holding the reload value for X counter in the Y register) but
currently this can't be used, because the autopull threshold is associated with the program, instead of the SM
instantiation.

3.9.5. PWM

A PWM example,
Pico MicroPython Examples:
1 # Example of using PIO for PWM, and fading the brightness of an LED
2
3 from
4 from
5 from
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7
8 @asm_pio(sideset_init=PIO.OUT_LOW)
9 def pwm_prog():
10 pull(noblock) .side(0)
11 mov(x, osr)
12 mov(y, isr)
3.9. PIO Support
.side(0x1)
.side(0x0)
PIOSPI:
__init__(self, sm_id, pin_mosi, pin_miso, pin_sck, cpha=False, cpol=False, freq
assert(not(cpol or cpha))
self._sm = rp2.StateMachine(sm_id, spi_cpha0, freq=4*freq, sideset_base=Pin(
self._sm.active(1)
write_blocking(wdata):
for b in wdata:
self._sm.put(b << 24)
read_blocking(n):
data = []
for i in range(n):
data.append(self._sm.get() & 0xff)
return data
write_read_blocking(wdata):
rdata = []
for b in wdata:
self._sm.put(b << 24)
rdata.append(self._sm.get() & 0xff)
return rdata
https://github.com/raspberrypi/pico-micropython-examples/tree/master/pio/pio_pwm.py
machine import Pin
rp2 import PIO, StateMachine, asm_pio
time import sleep
# Keep most recent pull data stashed in X, for recycling by noblock
# ISR must be preloaded with PWM count max
# Fallthru if TXF empties
[1] # CSn back porch
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