Create dht_time_calibration.py

Addition of a script to test best timing for DHT sensor.

examples/dht_time_calibration.py

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+import json
+import time
+
+import board
+
+import adafruit_dht
+
+pin_to_use = 'PG6'
+
+# Maximum number of tries per timing
+max_retries_per_time = 10
+# Minimum time from where to start testing
+min_time = 500
+# Maximum time on where to stop testing
+max_time = 2000
+# Increment on time
+time_increment = 100
+
+# Variable to store all reads on a try
+reads = {}
+
+print("\nInitializing test.\n")
+
+for milliseconds in range(min_time, max_time, time_increment):
+    # Instantiate the DHT11 object.
+    dhtDevice = adafruit_dht.DHT11(pin=getattr(board, pin_to_use))
+    # Change the default wait time for triggering the read.
+    dhtDevice._trig_wait = milliseconds
+
+    print(f"Using 'trig_wait' of {dhtDevice._trig_wait}")
+    # Reset the read count for next loop
+    reads_count = 0
+
+    # Create the key on the reads dictionary with the milliseconds used on
+    # this try.
+    if milliseconds not in reads:
+        reads[milliseconds] = {
+            "total_reads": 0
+        }
+
+    for try_number in range(0, max_retries_per_time):
+        try:
+            # Read temperature and humidity
+            temperature = dhtDevice.temperature
+            humidity = dhtDevice.humidity
+            read_values = {
+                "temperature": temperature,
+                "humidity": humidity
+            }
+
+            if try_number not in reads[milliseconds]:
+                reads[milliseconds][try_number] = read_values
+
+            reads_count += 1
+        except RuntimeError as e:
+            time.sleep(2)
+        else:
+            time.sleep(1)
+
+    reads[milliseconds]["total_reads"] = reads_count
+
+    print(f"Total read(s): {reads[milliseconds]['total_reads']}\n")
+    dhtDevice.exit()
+
+
+# Gather the highest read numbers from all reads done.
+best_result = max(
+    [
+        reads[milliseconds]["total_reads"] for milliseconds in reads
+    ]
+)
+
+# Gather best time(s) in milliseconds where we got more reads
+best_times = [
+    milliseconds for milliseconds in reads if reads[milliseconds]['total_reads'] == best_result
+]
+print(
+    f"Maximum reads: {best_result} with the "
+    f"following times: {''.join([str(t) for t in best_times])}"
+)
+
+# change the value on the line below to see all reads performed.
+print_all = False
+print(json.dumps(reads)) if print_all else None