Add digital channels

Author: NejcKle

example.py

@@ -32,8 +32,17 @@
 for i in range(0, 1000):
     read_data = ppk2_test.get_data()
     if read_data != b'':
-        samples = ppk2_test.get_samples(read_data)
+        samples, raw_digital = ppk2_test.get_samples(read_data)
         print(f"Average of {len(samples)} samples is: {sum(samples)/len(samples)}uA")
+
+        # Raw digital contains the raw digital data from the PPK2
+        # The number of raw samples is equal to the number of samples in the samples list
+        # We have to process the raw digital data to get the actual digital data
+        digital_channels = ppk2_test.digital_channels(raw_digital)
+        for ch in digital_channels:
+            # Print last 10 values of each channel
+            print(ch[-10:])
+        print()
     time.sleep(0.01)
 
 ppk2_test.toggle_DUT_power("OFF")  # disable DUT power
@@ -44,8 +53,17 @@
 for i in range(0, 1000):
     read_data = ppk2_test.get_data()
     if read_data != b'':
-        samples = ppk2_test.get_samples(read_data)
+        samples, raw_digital = ppk2_test.get_samples(read_data)
         print(f"Average of {len(samples)} samples is: {sum(samples)/len(samples)}uA")
+
+        # Raw digital contains the raw digital data from the PPK2
+        # The number of raw samples is equal to the number of samples in the samples list
+        # We have to process the raw digital data to get the actual digital data
+        digital_channels = ppk2_test.digital_channels(raw_digital)
+        for ch in digital_channels:
+            # Print last 10 values of each channel
+            print(ch[-10:])
+        print()
     time.sleep(0.01)  # lower time between sampling -> less samples read in one sampling period
 
 ppk2_test.stop_measuring()

example_mp.py

@@ -17,10 +17,13 @@
     print(f'Too many connected PPK2\'s: {ppk2s_connected}')
     exit()
 
-ppk2_test = PPK2_API(ppk2_port, buffer_max_size_seconds=1, buffer_chunk_seconds=0.01)
+ppk2_test = PPK2_API(ppk2_port, buffer_max_size_seconds=70, buffer_chunk_seconds=0.5)
 ppk2_test.get_modifiers()
 ppk2_test.set_source_voltage(3300)
 
+"""
+Source mode example
+"""
 ppk2_test.use_source_meter()  # set source meter mode
 ppk2_test.toggle_DUT_power("ON")  # enable DUT power
 
@@ -29,23 +32,46 @@
 # the number of measurements in one sampling period depends on the wait between serial reads
 # it appears the maximum number of bytes received is 1024
 # the sampling rate of the PPK2 is 100 samples per millisecond
-for i in range(0, 1000):
+while True:
     read_data = ppk2_test.get_data()
     if read_data != b'':
-        samples = ppk2_test.get_samples(read_data)
+        samples, raw_digital = ppk2_test.get_samples(read_data)
         print(f"Average of {len(samples)} samples is: {sum(samples)/len(samples)}uA")
+
+        # Raw digital contains the raw digital data from the PPK2
+        # The number of raw samples is equal to the number of samples in the samples list
+        # We have to process the raw digital data to get the actual digital data
+        digital_channels = ppk2_test.digital_channels(raw_digital)
+        for ch in digital_channels:
+            # Print last 10 values of each channel
+            print(ch[-10:])
+        print()
+
     time.sleep(0.001)
 
 ppk2_test.toggle_DUT_power("OFF")  # disable DUT power
+ppk2_test.stop_measuring()
 
+"""
+Ampere mode example
+"""
 ppk2_test.use_ampere_meter()  # set ampere meter mode
 
 ppk2_test.start_measuring()
-for i in range(0, 1000):
+while True:
     read_data = ppk2_test.get_data()
     if read_data != b'':
-        samples = ppk2_test.get_samples(read_data)
+        samples, raw_digital = ppk2_test.get_samples(read_data)
         print(f"Average of {len(samples)} samples is: {sum(samples)/len(samples)}uA")
+
+        # Raw digital contains the raw digital data from the PPK2
+        # The number of raw samples is equal to the number of samples in the samples list
+        # We have to process the raw digital data to get the actual digital data
+        digital_channels = ppk2_test.digital_channels(raw_digital)
+        for ch in digital_channels:
+            # Print last 10 values of each channel
+            print(ch[-10:])
+        print()
     time.sleep(0.001)  # lower time between sampling -> less samples read in one sampling period
 
-ppk2_test.stop_measuring()
+# ppk2_test.stop_measuring()

src/ppk2_api/ppk2_api.py

@@ -189,11 +189,10 @@ def _generate_mask(self, bits, pos):
         mask = self._twos_comp(mask)
         return {"mask": mask, "pos": pos}
 
-    def _get_masked_value(self, value, meas):
+    def _get_masked_value(self, value, meas, is_bits=False):
+        # print(f"Value: {value}")
+        # print(f"Meas: {meas}")
         masked_value = (value & meas["mask"]) >> meas["pos"]
-        if meas["pos"] == 24:
-            if masked_value == 255:
-                masked_value = -1
         return masked_value
 
     def _handle_raw_data(self, adc_value):
@@ -205,10 +204,10 @@ def _handle_raw_data(self, adc_value):
             bits = self._get_masked_value(adc_value, self.MEAS_LOGIC)
             analog_value = self.get_adc_result(
                 current_measurement_range, adc_result) * 10**6
-            return analog_value
+            return analog_value, bits
         except Exception as e:
             print("Measurement outside of range!")
-            return None
+            return None, None
 
     @staticmethod
     def list_devices():
@@ -327,6 +326,26 @@ def _digital_to_analog(self, adc_value):
         """Convert discrete value to analog value"""
         return int.from_bytes(adc_value, byteorder="little", signed=False)  # convert reading to analog value
 
+    def digital_channels(self, bits):
+        """
+        Convert raw digital data to digital channels.
+
+        Returns a 2d matrix with 8 rows (one for each channel). Each row contains HIGH and LOW values for the selected channel.
+        """
+
+        # Prepare 2d matrix with 8 rows (one for each channel)
+        digital_channels = [[], [], [], [], [], [], [], []]
+        for sample in bits:
+            digital_channels[0].append((sample & 1) >> 0)
+            digital_channels[1].append((sample & 2) >> 1)
+            digital_channels[2].append((sample & 4) >> 2)
+            digital_channels[3].append((sample & 8) >> 3)
+            digital_channels[4].append((sample & 16) >> 4)
+            digital_channels[5].append((sample & 32) >> 5)
+            digital_channels[6].append((sample & 64) >> 6)
+            digital_channels[7].append((sample & 128) >> 7)
+        return digital_channels
+
     def get_samples(self, buf):
         """
         Returns list of samples read in one sampling period.
@@ -338,28 +357,35 @@ def get_samples(self, buf):
         sample_size = 4  # one analog value is 4 bytes in size
         offset = self.remainder["len"]
         samples = []
+        raw_digital_output = []
 
         first_reading = (
             self.remainder["sequence"] + buf[0:sample_size-offset])[:4]
         adc_val = self._digital_to_analog(first_reading)
-        measurement = self._handle_raw_data(adc_val)
+        measurement, bits = self._handle_raw_data(adc_val)
         if measurement is not None:
             samples.append(measurement)
+        if bits is not None:
+            raw_digital_output.append(bits)
 
         offset = sample_size - offset
 
         while offset <= len(buf) - sample_size:
             next_val = buf[offset:offset + sample_size]
             offset += sample_size
             adc_val = self._digital_to_analog(next_val)
-            measurement = self._handle_raw_data(adc_val)
+            measurement, bits = self._handle_raw_data(adc_val)
             if measurement is not None:
                 samples.append(measurement)
+            if bits is not None:
+                raw_digital_output.append(bits)
 
         self.remainder["sequence"] = buf[offset:len(buf)]
         self.remainder["len"] = len(buf)-offset
 
-        return samples  # return list of samples, handle those lists in PPK2 API wrapper
+        # return list of samples and raw digital outputs
+        # handle those lists in PPK2 API wrapper
+        return samples, raw_digital_output  
 
 
 class PPK_Fetch(threading.Thread):