From 7296d5c22b7be7cb4219fe9bcab73970064ebe93 Mon Sep 17 00:00:00 2001 From: Peter Hinch Date: Mon, 16 Sep 2024 17:59:33 +0100 Subject: [PATCH] encoder_rp2.py: Add code comment re pullups. --- encoders/encoder_rp2.py | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/encoders/encoder_rp2.py b/encoders/encoder_rp2.py index 255a077..b157ded 100644 --- a/encoders/encoder_rp2.py +++ b/encoders/encoder_rp2.py @@ -11,33 +11,37 @@ from array import array import rp2 # Test with encoder on pins 2 and 3: -#e = Encoder(0, Pin(2)) +# e = Encoder(0, Pin(2)) -#while True: - #time.sleep(1) - #print(e.value()) +# while True: +# time.sleep(1) +# print(e.value()) # Closure enables Viper to retain state. Currently (V1.17) nonlocal doesn't # work: https://github.com/micropython/micropython/issues/8086 # so using arrays. def make_isr(pos): - old_x = array('i', (0,)) + old_x = array("i", (0,)) + @micropython.viper def isr(sm): i = ptr32(pos) p = ptr32(old_x) while sm.rx_fifo(): - v : int = int(sm.get()) & 3 - x : int = v & 1 - y : int = v >> 1 - s : int = 1 if (x ^ y) else -1 + v: int = int(sm.get()) & 3 + x: int = v & 1 + y: int = v >> 1 + s: int = 1 if (x ^ y) else -1 i[0] = i[0] + (s if (x ^ p[0]) else (0 - s)) p[0] = x + return isr + # Args: # StateMachine no. (0-7): each instance must have a different sm_no. # An initialised input Pin: this and the next pin are the encoder interface. +# Pins must have pullups (internal or, preferably, low value 1KΩ to 3.3V). class Encoder: def __init__(self, sm_no, base_pin, scale=1): self.scale = scale