Differences

This shows you the differences between two versions of the page.

Link to this comparison view

--- en:iot-open:remotelab:sut:generalpurpose [2019/10/26 10:48] – pczekalski
+++ en:iot-open:remotelab:sut:generalpurpose [Unknown date] (current) – external edit (Unknown date) 127.0.0.1
@@ Line 1: / Line 1: @@
-===== VREL #2 and #4: General Purpose IoT Laboratory, air pushing nodes 2 and 4 =====
+====== VREL #2 and #4: General Purpose IoT Laboratory, air pushing nodes 2 and 4 ======
 The laboratory is located at Silesian Technical University, Poland, Gliwice Akademicka 16, room 310.
-==== Introduction  ====
+===== Introduction  =====
 The node is an airflow generator, connected to the appropriate air receiving node. There is an air duct that connects nodes (node 2 send air to node 1, while node 4 send air to node 3).
 The lab consists of the fan which is a source of airflow going to the air duct. The beam of the airflow can be regulated in two ways:
@@ Line 9: / Line 9: @@
 The voltage on the fan is visible on needle multimeter.
-==== Prerequisites ====
+===== Prerequisites =====
 The user needs to know:
   * physical effect of the airflow,
@@ Line 15: / Line 15: @@
   * working od servo-motors and its control.
-==== Technical details ====
+===== Technical details =====
 End of the pipe is fitted to fan which is covered by rectangle flap. The flap is hanging on servomotor lever. Both fan and servomotor, are connected to the PWM outputs (each has its pin, enabling to control them independently) from the SoC. It is possible to change the rotating speed of the fan, and also the position of the flap. Parallel, the voltage on the fan (effective value), is displayed on analogue spindle voltage meter and can be observed via camera.
-{{:en:iot-open:remotelab:sut:iottx.jpg?500|}}
+{{:en:iot-open:remotelab:sut:iottx.jpg?470|}}
-=== Sensors ===
+===== Sensors =====
-There is temperature and humidity sensor in the lab node: DHT22, connected to the GPIO0 (D3).
+There is a temperature and humidity sensor in the lab node: DHT11, connected to the GPIO0 (D4).
-=== Actuators ===
+===== Actuators =====
 There are two actuators (fan, servo) and LCD display.
   * The fan is a DC controlled one, where using PWM one can change rotation speed.
     * the pin is GPIO 15/ D8
-  * The servo is an analogue servo, emax ES08A II:
+  * The servo is an analogue servo, Emax ES08A II:
     * min timing 1500us max timing 1900us
     * the pin is GPIO 14 / D5
@@ Line 37: / Line 37: @@
       * SCL GPIO4 / D2
-{{:en:iot-open:remotelab:sut:iottx_sch.jpg?500|}}
+{{:en:iot-open:remotelab:sut:iottx_sch.jpg?470|}}
-=== Software, libraries and externals ===
+===== Software, libraries and externals =====
 LCD display requires a dedicated library. Of course, you can control it on the low-level programming, writing directly to the I2C registers, but we do suggest using a library first. As there are many universal libraries, and many of them are incompatible with this display, we strongly recommend using [[https://github.com/tonykambo/LiquidCrystal_I2C|''LiquidCrystal_I2C by Tony Kambourakis'']].
 The LCD I2C control library can be imported to the source code via:
@@ Line 47: / Line 47: @@
 Then configure your LCD controller:
 <code c>
-LiquidCrystal_I2C lcd(0x3F,20,4);  // set the LCD address to 0x3F for a 20 chars and 4 line display
+LiquidCrystal_I2C lcd(0x3F,20,4);  // set the LCD address to 0x3F
+                                   // for a 20 chars and 4 line display
 </code>
-== Platformio.ini ==
-<code>
-; PlatformIO Project Configuration File
-;
-;   Build options: build flags, source filter
-;   Upload options: custom upload port, speed and extra flags
-;   Library options: dependencies, extra library storages
-;   Advanced options: extra scripting
-;
-; Please visit documentation for the other options and examples
-; http://docs.platformio.org/page/projectconf.html
-[env:d1_mini]
-platform = espressif8266
-board = d1_mini
-framework = arduino
-lib_deps = Wire, EmonLib, Adafruit NeoPixel, Encoder,DHT sensor library, Adafruit Unified Sensor, LCD, PubSubClient, KS0108_PCF8574, CoAP simple library
-</code>
 === Communication ===
@@ Line 88: / Line 71: @@
-==== Support ====
+===== 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/generalpurpose.1572086889.txt.gz · Last modified: 2020/07/20 09:00 (external edit)