From a95b06fc6b8adefa91303039cff0a35d3ae45d5a Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 30 Jul 2015 23:10:39 +0100
Subject: [PATCH] drivers/onewire: Fix ds18x20.read_temp so it works when no
rom given.
---
drivers/onewire/ds18x20.py | 20 +++++++-------------
1 file changed, 7 insertions(+), 13 deletions(-)
diff --git a/drivers/onewire/ds18x20.py b/drivers/onewire/ds18x20.py
index 06c9fc968..a2f7f5c3d 100644
--- a/drivers/onewire/ds18x20.py
+++ b/drivers/onewire/ds18x20.py
@@ -7,14 +7,13 @@ temperature sensors. It supports multiple devices on the same 1-wire bus.
The following example assumes the ground of your DS18x20 is connected to
Y11, vcc is connected to Y9 and the data pin is connected to Y10.
->>> gnd = Pin('Y11')
->>> gnd.init(Pin.OUT_PP)
+>>> from pyb import Pin
+>>> gnd = Pin('Y11', Pin.OUT_PP)
>>> gnd.low()
-
->>> vcc = Pin('Y9')
->>> vcc.init(Pin.OUT_PP)
+>>> vcc = Pin('Y9', Pin.OUT_PP)
>>> vcc.high()
+>>> from ds18x20 import DS18X20
>>> d = DS18X20(Pin('Y10'))
Call read_temps to read all sensors:
@@ -47,27 +46,22 @@ class DS18X20(object):
# correct # first byte in their rom for a DS18x20 device.
self.roms = [rom for rom in self.ow.scan() if rom[0] == 0x10 or rom[0] == 0x28]
- def _select_rom(self, rom):
- if rom:
- self.ow.select_rom(rom)
- else:
- self.ow.skip_rom()
-
def read_temp(self, rom=None):
"""
Read and return the temperature of one DS18x20 device.
Pass the 8-byte bytes object with the ROM of the specific device you want to read.
If only one DS18x20 device is attached to the bus you may omit the rom parameter.
"""
+ rom = rom or self.roms[0]
ow = self.ow
ow.reset()
- self._select_rom(rom)
+ ow.select_rom(rom)
ow.write_byte(0x44) # Convert Temp
while True:
if ow.read_bit():
break
ow.reset()
- self._select_rom(rom)
+ ow.select_rom(rom)
ow.write_byte(0xbe) # Read scratch
data = ow.read_bytes(9)
return self.convert_temp(rom[0], data)
--
GitLab