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revise RESET to avoid need for Pull-UP #47

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Merged
merged 1 commit into from
Aug 9, 2020
Merged

revise RESET to avoid need for Pull-UP #47

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14 changes: 6 additions & 8 deletions adafruit_rfm9x.py
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Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,6 @@
"""
import time
import random
import digitalio
from micropython import const


Expand Down Expand Up @@ -245,12 +244,11 @@ def __init__(
# Device support SPI mode 0 (polarity & phase = 0) up to a max of 10mhz.
# Set Default Baudrate to 5MHz to avoid problems
self._device = spidev.SPIDevice(spi, cs, baudrate=baudrate, polarity=0, phase=0)
# Setup reset as a digital input (default state for reset line according
# to the datasheet). This line is pulled low as an output quickly to
# trigger a reset. Note that reset MUST be done like this and set as
# a high impedence input or else the chip cannot change modes (trust me!).
# Setup reset as a digital output - initially High
# This line is pulled low as an output quickly to trigger a reset.
self._reset = reset
self._reset.switch_to_input(pull=digitalio.Pull.UP)
# initialize Reset High
self._reset.switch_to_output(value=True)
self.reset()
# No device type check! Catch an error from the very first request and
# throw a nicer message to indicate possible wiring problems.
Expand Down Expand Up @@ -385,9 +383,9 @@ def _write_u8(self, address, val):
def reset(self):
"""Perform a reset of the chip."""
# See section 7.2.2 of the datasheet for reset description.
self._reset.switch_to_output(value=False)
self._reset.value = False # Set Reset Low
time.sleep(0.0001) # 100 us
self._reset.switch_to_input(pull=digitalio.Pull.UP)
self._reset.value = True # set Reset High
time.sleep(0.005) # 5 ms

def idle(self):
Expand Down