fix LSB constants + add is_ready property

barbudor · Jan 4, 2021 · cf73188 · cf73188
1 parent 39fe4a4
commit cf73188
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Showing 3 changed files with 20 additions and 6 deletions.
diff --git a/barbudor_ina3221/full.py b/barbudor_ina3221/full.py
@@ -143,8 +143,9 @@
 C_DIE_ID                          = const(0x3220)
 
 # General constants
-C_BUS_ADC_LSB                     = const(0.008)      # VBus ADC LSB is 8mV
-C_SHUNT_ADC_LSB                   = const(0.00004)    # VShunt ADC LSB is 40µV
+C_BUS_ADC_LSB                     = 0.008             # VBus ADC LSB is 8mV
+C_SHUNT_ADC_LSB                   = 0.00004           # VShunt ADC LSB is 40µV
+
 
 class INA3221:
     """Driver class for Texas Instruments INA3221 3 channel current sensor device"""
@@ -256,3 +257,9 @@ def set_shunt_warning_alert_limit(self, channel, voltage):
         assert 1 <= channel <= 3, "channel argument must be 1, 2, or 3"
         value = self._to_unsigned(round(voltage * C_SHUNT_ADC_LSB) * 8)
         self.write(C_REG_WARNING_ALERT_LIMIT_CH[channel], value)
+
+    @property
+    def is_ready(self):
+        """Returns the CVRF (ConVersion Ready Flag) from the mask/enable register """
+        regvalue = self.read(C_REG_MASK_ENABLE)
+        return (regvalue & C_CONV_READY_FLAG) != 0
diff --git a/barbudor_ina3221/lite.py b/barbudor_ina3221/lite.py
@@ -143,8 +143,8 @@
 _DIE_ID                          = const(0x3220)
 
 # General constants
-C_BUS_ADC_LSB                    = const(0.008)      # VBus ADC LSB is 8mV
-C_SHUNT_ADC_LSB                  = const(0.00004)    # VShunt ADC LSB is 40µV
+C_BUS_ADC_LSB                    = 0.008             # VBus ADC LSB is 8mV
+C_SHUNT_ADC_LSB                  = 0.00004           # VShunt ADC LSB is 40µV
 
 
 class INA3221:
@@ -230,4 +230,4 @@ def bus_voltage(self, channel=1):
         #assert 1 <= channel <= 3, "channel argument must be 1, 2, or 3"
         value = self._to_signed(self.read(_REG_BUS_VOLTAGE_CH[channel])) / 8
         # convert to volts - LSB = 8mV
-        return value * C_BUS_ADC_LSB
+        return value * C_BUS_ADC_LSB
diff --git a/examples/ina3221_simpletest.py b/examples/ina3221_simpletest.py
@@ -19,6 +19,8 @@
 if INA3221.IS_FULL_API:
     print("full API sample: improve accuracy")
     # improve accuracy by slower conversion and higher averaging
+    # each conversion now takes 128*0.008 = 1.024 sec
+    # which means 2 seconds per channel
     ina3221.update(reg=C_REG_CONFIG,
                    mask=C_AVERAGING_MASK |
                    C_VBUS_CONV_TIME_MASK |
@@ -37,6 +39,11 @@
 # pylint: disable=bad-whitespace
 
 while True:
+    if INA3221.IS_FULL_API: # is_ready available only in "full" variant
+        while not ina3221.is_ready:
+            print(".",end='')
+            time.sleep(0.1)
+        print("")
 
     print("------------------------------")
     line_title =         "Measurement   "
@@ -64,4 +71,4 @@
     print(line_shunt_voltage)
     print(line_current)
 
-    time.sleep(2.0)
+    time.sleep(2.0)