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--- en:iot-open:remotelab:sut:generalpurpose2 [2020/07/20 11:26] – external edit 127.0.0.1
+++ en:iot-open:remotelab:sut:generalpurpose2 [Unknown date] (current) – external edit (Unknown date) 127.0.0.1
@@ Line 17: / Line 17: @@
 ==== Technical details for the flap position monitor ====
-End of the air duct is fitted to rectangle flap, The flap is hanging loosely and can be pushed by the airflow. The flap is lighted by LED form the top, and at the opposite side of the flap, there is the photoresistor, which measures light intensity, reflected from the flap. The flap sensing system is connected to the analogue input A0.
+The end of the air duct is fitted to a rectangle flap, The flap is hanging loosely and can be pushed by the airflow. The flap is lighted by LED form the top, and at the opposite side of the flap, there is the photoresistor, which measures light intensity, reflected from the flap. The flap sensing system is connected to the analogue input A0.
 {{:en:iot-open:remotelab:sut:iotrx.jpg?470|}}
-Independent, in the lab there is a sensor of temperature and humidity, DHT22, connected to the D4/GPIO2.
+Independent, in the lab there is a sensor of temperature and humidity, DHT11, connected to the D4/GPIO2.
 {{:en:iot-open:remotelab:sut:iotrx_sch.jpg?470|}}
@@ Line 63: / Line 63: @@
 ===== Support =====
-gabriel.drabik@polsl.pl
+In case the LCD display hangs and you are sure that your code should work but it does not, it may be the case the I2C bus is stuck and hang the I2C to LCD controller converter.\\
+In this case, please use the following code to reset the I2C bus (you can embed it to your source code or run separately, then run your original code, again):
+<code c>
+#include <Arduino.h>
+#include <LiquidCrystal_I2C.h>
+LiquidCrystal_I2C lcd(0x3F,20,4);
+void setup()
+{
+  pinMode(4,OUTPUT);
+  pinMode(5, OUTPUT);
+  digitalWrite(4,LOW);
+  digitalWrite(5,LOW);
+  delay(2000);
+  pinMode(5, INPUT);       // reset pin
+  pinMode(4, INPUT);
+  delay(2050);
+  lcd.init(D2,D1);
+  lcd.backlight();
+  lcd.home();
+  lcd.print("Hello world...");
+}
+void loop()
+{
+}
+</code>
+Finally, you should see Hello World message on the LCD and I2C bus should be recovered now.

en/iot-open/remotelab/sut/generalpurpose2.1595244387.txt.gz · Last modified: 2020/07/20 09:00 (external edit)