Thermistor

.gitignore

@@ -60,3 +60,4 @@ docs/_build/
 target/
 
 .idea/
+pitmaster/csv/

pitmaster/executable.py

@@ -55,6 +55,20 @@ def _setup_arg_parser():
         action='store_true',
         help="Enable the LCD display or not. It is disabled by default."
     )
+    parser.add_argument(
+        "-l",
+        "--localdisplay",
+        action='store_true',
+        help="Enable console output or not. It is disabled by default."
+    )
+    parser.add_argument(
+        "-p",
+        "--probetype",
+        required=True,
+        action='store',
+        help="Configure which type of probes to use."
+             "This is either thermistor or thermocouple"
+    )
     return parser
 
 
@@ -69,15 +83,17 @@ def execute():
     cook_name = provided_args.cookname
     output_file = provided_args.output
     use_lcd = provided_args.tft
-    sensors = sensor.find_temp_sensors()
+    probe_type = provided_args.probetype
+    local_display = provided_args.localdisplay
+    sensors = sensor.find_temp_sensors(probe_type)
     data_obj = DBObject(filename=output_file)
     if use_lcd:
         display = LocalDisplay()
         display.set_display_msg("Welcome!")
     try:
         while True:
             for sen in sensors:
-                temp_c = sensor.read_temp(sen["location"])
+                temp_c = sensor.read_temp(sen["location"], probe_type=probe_type)
                 temp_f = temps.from_c_to_f(temp=temp_c)
                 info = {
                     "date": time.time(),
@@ -87,6 +103,8 @@ def execute():
                     "cook_name": cook_name
                 }
                 data_obj.save(info=info)
+                if local_display:
+                    print info
                 if use_lcd:
                     display.check_events()
                     display.set_display_msg("{}: {}f".format(

pitmaster/tools/sensor.py

@@ -13,17 +13,92 @@
 #   limitations under the License.
 import os
 import time
+import math
+import RPi.GPIO as GPIO
 
 from pitmaster.exceptions import *
 
+SPICLK = 18
+SPIMOSI = 24
+SPIMISO = 23
+SPICS = 25
+
+GPIO.setmode(GPIO.BCM)
+DEBUG = 1
+# set up the SPI interface pins
+GPIO.setup(SPIMOSI, GPIO.OUT)
+GPIO.setup(SPIMISO, GPIO.IN)
+GPIO.setup(SPICLK, GPIO.OUT)
+GPIO.setup(SPICS, GPIO.OUT)
+
 
 def _temp_raw(sensor=None):
     with open(sensor, "r") as file_reader:
         lines = file_reader.readlines()
     return lines
 
 
-def read_temp(sensor=None, offset=None):
+def _read_thermistor(sensor=None):
+    adcnum = int(sensor)
+    clockpin = SPICLK
+    mosipin = SPIMOSI
+    misopin = SPIMISO
+    cspin = SPICS
+
+    if ((adcnum > 7) or (adcnum < 0)):
+        raise SensorNotFoundException("Invalid Thermisor Location: {}".format(sensor))
+
+    GPIO.output(cspin, True)
+    GPIO.output(clockpin, False)  # start clock low
+    GPIO.output(cspin, False)     # bring CS low
+
+    commandout = adcnum
+    commandout |= 0x18  # start bit + single-ended bit
+    commandout <<= 3    # we only need to send 5 bits here
+
+    for i in range(5):
+            if (commandout & 0x80):
+                    GPIO.output(mosipin, True)
+            else:
+                    GPIO.output(mosipin, False)
+            commandout <<= 1
+            GPIO.output(clockpin, True)
+            GPIO.output(clockpin, False)
+
+    adcout = 0
+    # read in one empty bit, one null bit and 10 ADC bits
+    for i in range(12):
+            GPIO.output(clockpin, True)
+            GPIO.output(clockpin, False)
+            adcout <<= 1
+            if (GPIO.input(misopin)):
+                    adcout |= 0x1
+
+    GPIO.output(cspin, True)
+
+    adcout >>= 1       # first bit is 'null' so drop it
+    resistor_size = 10000
+    r1 = (1023.0 / adcout) - 1.0
+    if r1 > 0:
+        resistance = resistor_size / r1
+    else:
+        return -1
+
+    sth_coef_a = 0.000436925136556
+    sth_coef_b = 0.000230203788274
+    sth_coef_c = 0.000000060486575
+
+    if resistance is None:
+        raise MissingPropertyException("resistance can not be None!")
+    t = sth_coef_a
+    t += sth_coef_b * (math.log(resistance))
+    t += sth_coef_c * math.pow((math.log(resistance)), 3)
+    t = 1 / t
+    t -= 273.15
+    return t
+
+
+def read_temp(sensor=None, offset=None, probe_type=None):
     """
     Reads the temp sensor and returns its temp in C.
 
@@ -33,34 +108,60 @@ def read_temp(sensor=None, offset=None):
     """
     if sensor is None:
         raise MissingPropertyException("sensor must not be None!")
+    if probe_type is None:
+        raise MissingPropertyException("must specify probe type!")
     if offset is None:
         offset = 0
-    if not os.path.isfile(sensor):
-        raise SensorNotFoundException("Unable to locate: {}".format(sensor))
-    lines = _temp_raw(sensor)
-    while lines[0].strip()[-3] != 'Y':
-        time.sleep(0.2)
-        lines = _temp_raw()
-    temp_output = lines[1].find('t=')
-    if temp_output != -1:
-        temp_string = lines[1].strip()[temp_output + 2:]
-        temp_c = (float(temp_string) / 1000.0) + offset
+    if probe_type != "thermistor":
+        if not os.path.isfile(sensor):
+            raise SensorNotFoundException("Unable to locate: {}".format(sensor))
+        lines = _temp_raw(sensor)
+        while lines[0].strip()[-3] != 'Y':
+            time.sleep(0.2)
+            lines = _temp_raw()
+        temp_output = lines[1].find('t=')
+        if temp_output != -1:
+            temp_string = lines[1].strip()[temp_output + 2:]
+            temp_c = (float(temp_string) / 1000.0) + offset
+            return temp_c
+    else:
+        temp_c = _read_thermistor(sensor) + offset
         return temp_c
 
 
-def find_temp_sensors():
+def find_temp_sensors(probe_type=None):
     """
     Looks on system for temp sensors and returns all that it finds in a list
 
     :return list: List containing all sensors.
     """
-    # Hard coded for now while we work out the best way to handel this.
-    return [
-        {
-            "name": "Probe 1",
-            "location": "/sys/bus/w1/devices/3b-0000001921e8/w1_slave"
-        }
-    ]
+    if probe_type is None:
+        raise MissingPropertyException("probe type must be set!")
+
+    if probe_type == "thermistor":
+        return [
+            {
+                "name": "Probe 1",
+                "location": "0"
+            },
+            {
+                "name": "Probe 2",
+                "location": "1"
+            },
+            {
+                "name": "Probe 3",
+                "location": "2"
+            }
+        ]
+    else:
+        # Hard coded for now while we work out the best way to handel this.
+        return [
+            {
+                "name": "Probe 1",
+                "location": "/sys/bus/w1/devices/3b-0000001921e8/w1_slave"
+            }
+        ]
+
 
 if __name__ == "__main__":
     for i in range(15):

pitmaster/tools/temps.py

@@ -12,6 +12,7 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 from numbers import Number
+import math
 
 from pitmaster.exceptions import *
 
@@ -29,4 +30,4 @@ def from_c_to_f(temp=None):
         raise InvalidPropertyException(
             "temp must be a valid number. Found: {}".format(type(temp))
         )
-    return (temp * 9/5) + 32.0
+    return (temp * 9 / 5) + 32.0