From 7b4b208c8579ede963f2c4ecd2543ca0900e2210 Mon Sep 17 00:00:00 2001
From: Mark Leary <leary.mark@gmail.com>
Date: Wed, 15 Dec 2021 10:43:19 -0500
Subject: [PATCH] Retry when DHT temp sensor read fails

---
 octoprint_enclosure/getDHTTemp.py | 34 +++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/octoprint_enclosure/getDHTTemp.py b/octoprint_enclosure/getDHTTemp.py
index cb9bfef..e898977 100644
--- a/octoprint_enclosure/getDHTTemp.py
+++ b/octoprint_enclosure/getDHTTemp.py
@@ -1,9 +1,10 @@
 import sys
+import time
 import adafruit_dht
 
 
 # Parse command line parameters.
-sensor_args =   {   
+sensor_args =   {
                     '11': adafruit_dht.DHT11,
                     '22': adafruit_dht.DHT22,
                     '2302': adafruit_dht.DHT22
@@ -16,12 +17,29 @@
     sys.exit(1)
 
 dht_dev = sensor(pin)
-humidity = dht_dev.humidity
-temperature = dht_dev.temperature
 
-if humidity is not None and temperature is not None:
-    print('{0:0.1f} | {1:0.1f}'.format(temperature, humidity))
-else:
-    print('-1 | -1')
+# DHT sensor read fails quite often, causing enclosure plugin to report value of 0.
+# If this happens, retry as suggested in the adafruit_dht docs.
+max_retries = 3
+retry_count = 0
+while retry_count <= max_retries:
+    try:
+        humidity = dht_dev.humidity
+        temperature = dht_dev.temperature
+
+        if humidity is not None and temperature is not None:
+            print('{0:0.1f} | {1:0.1f}'.format(temperature, humidity))
+            sys.exit(1)
+    except RuntimeError as e:
+        time.sleep(2)
+        retry_count += 1
+        continue
+    except Exception as e:
+        dht_dev.exit()
+        raise e
+
+    time.sleep(1)
+    retry_count += 1
 
-sys.exit(1)
+print('-1 | -1')
+sys.exit(1)
\ No newline at end of file