ugnen

commit c4d7b388c39f52e5ebdb91feed1d77e0b6af5724
parent b4eaec0cfaf00ecb5c50cb393698fa15dc9911b7
Author: rbckman <rob@tarina.org>
Date:   Thu,  8 Sep 2022 11:19:02 +0300

reading temp with raspberry pi

Diffstat:
A
max6675.py
 | 
60
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
temp_read_1_sensor.py
 | 
39
+++++++++++++++++++++++++++++++++++++++

2 files changed, 99 insertions(+), 0 deletions(-)
diff --git a/max6675.py b/max6675.py
@@ -0,0 +1,60 @@
+import RPi.GPIO as GPIO
+import time
+GPIO.setmode(GPIO.BOARD)
+GPIO.setwarnings(False)
+
+# set pin number for communicate with MAX6675
+def set_pin (CS, SCK, SO, UNIT):
+    global sck
+    sck= SCK
+    global so
+    so = SO
+    global unit
+    unit = UNIT
+    
+    GPIO.setup(CS, GPIO.OUT, initial = GPIO.HIGH)
+    GPIO.setup(SCK, GPIO.OUT, initial = GPIO.LOW)
+    GPIO.setup(SO, GPIO.IN)
+
+def read_temp(cs_no):
+    
+    GPIO.output(cs_no, GPIO.LOW)
+    time.sleep(0.002)
+    GPIO.output(cs_no, GPIO.HIGH)
+    time.sleep(0.22)
+
+    GPIO.output(cs_no, GPIO.LOW)
+    GPIO.output(sck, GPIO.HIGH)
+    time.sleep(0.001)
+    GPIO.output(sck, GPIO.LOW)
+    Value = 0
+    for i in range(11, -1, -1):
+        GPIO.output(sck, GPIO.HIGH)
+        Value = Value + (GPIO.input(so) * (2 ** i))
+        GPIO.output(sck, GPIO.LOW)
+
+    GPIO.output(sck, GPIO.HIGH)
+    error_tc = GPIO.input(so)
+    GPIO.output(sck, GPIO.LOW)
+
+    for i in range(2):
+        GPIO.output(sck, GPIO.HIGH)
+        time.sleep(0.001)
+        GPIO.output(sck, GPIO.LOW)
+
+    GPIO.output(cs_no, GPIO.HIGH)
+
+    if unit == 0:
+        temp = Value
+    if unit == 1:
+        temp = Value * 0.25
+    if unit == 2:
+        temp = Value * 0.25 * 9.0 / 5.0 + 32.0
+
+    if error_tc != 0:
+        return -cs_no
+    else:
+        return temp
+
+GPIO.cleanup()
+
diff --git a/temp_read_1_sensor.py b/temp_read_1_sensor.py
@@ -0,0 +1,39 @@
+# before import the max6675, you must save the max6675.py file at "/usr/lib/python2.7/dist-packages"
+
+# wiring
+# Raspberry         MAX6675
+#       GND   ------   GND
+#        5V     ------   VCC
+#   pin 18     ------   SCK
+#   pin 22     ------   CS
+#   pin 16     ------   SO
+
+# import max6675 module.
+import max6675
+
+# set the pin for communicate with MAX6675
+cs = 22
+sck = 18
+so = 16
+
+# max6675.set_pin(CS, SCK, SO, unit)   [unit : 0 - raw, 1 - Celsius, 2 - Fahrenheit]
+max6675.set_pin(cs, sck, so, 1)
+
+try:
+    while 1:
+        # read temperature connected at CS 22
+        a = max6675.read_temp(cs)
+
+        # print temperature
+        print a
+
+        # when there are some errors with sensor, it return "-" sign and CS pin number
+        # in this case it returns "-22" 
+        
+        max6675.time.sleep(2)
+        
+except KeyboardInterrupt:
+    pass
+
+
+