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--- en:iot-open:remotelab:sut:generalpurpose3 [2020/04/26 21:15] – created pczekalski
+++ en:iot-open:remotelab:sut:generalpurpose3 [Unknown date] (current) – external edit (Unknown date) 127.0.0.1
@@ Line 14: / Line 14: @@
 ===== Sensors =====
 Each node contains the following set of sensors:
-  * DHT sensor measuring temperature and humidity (Blue is DHT11, White is DHT22) connected to the D4/GPIO2.
+  * DHT sensor measuring temperature and humidity DHT11, connected to the D4/GPIO2.
-  * Bosch BMP280 air pressure sensor, reporting absolute air pressure measurements in Pa, located inside of the yellow air chamber (operating of the fan changes pressure reported by the sensor when the fan is off, it measures absolute air pressure - please note, the laboratory is located at the 3rd floor + base floor, so it is not a ground-level pressure). This sensor uses I2C protocol and is connected to the D1 and D2 GPIOs (D2 is SDA, D1 is SCL).
+  * Bosch BMP280 air pressure sensor, reporting absolute air pressure measurements in Pa, located inside of the yellow air chamber (operating of the fan changes pressure reported by the sensor when the fan is off, it measures absolute air pressure - please note, the laboratory is located at the 3rd floor + base floor, so it is not a ground-level pressure). This sensor uses the I2C protocol and is connected to the D1 and D2 GPIOs (D2 is SDA, D1 is SCL). The sensor I2C address is 0x76.
 ==== Technical overview of the node and air pressure chamber overview ====
@@ Line 26: / Line 26: @@
 <figure VREL8_9_10_11>
 {{:en:iot-open:remotelab:sut:vrel8-11_bb.png?470|}}
-<caption>VREL components (circuit)</caption>
+<caption>VREL #8-#11 components (circuit)</caption>
 </figure>
 ===== Actuators =====
-There are no mechanical actuators in this laboratory.\\
+There are two mechanical actuators in this laboratory:
-LCD Display is 4x20 characters. LCD is controlled via I2C extender: LCM1602. The I2C extender address is 0x3F and the I2C bus is connected to the pins D1/GPIO5 and D2/GPIO4 (D1 is SCL and D2 is SDA).\\ As you do not have any access to the serial console, use LCD to visually trace the progress of your program, connection status, etc. By the LCD display, there are two LEDs that can be used to trace status. One LED is connected to the pin GPIO 16 while the other one to the GPIO pin 2. The former one (GPIO 2) is connected to the Serial Port TX as well so expect it flashing when communicating over serial protocol (i.e. flashing new firmware that is beyond the control of your code).
+  * Classical servo (180 degrees) controlled via pin D5 with arrow presenting its position.
+  * DC fan, located in the inlet of the air chamber, controlled with pin D8.
+LCD Display is 4x20 characters. LCD is controlled via I2C extender: LCM1602. The I2C extender address is 0x3F for nodes 8 and 9 and 0x27 for nodes 10 and 11. The I2C bus is connected to the pins D1/GPIO5 and D2/GPIO4 (D1 is SCL and D2 is SDA).\\ As you do not have any access to the serial console, use LCD to visually trace the progress of your program, connection status, etc. By the LCD display, there are two LEDs that can be used to trace status. One LED is connected to the pin GPIO 16 while the other one to the GPIO pin 2. The former one (GPIO 2) is connected to the Serial Port TX as well so expect it flashing when communicating over serial protocol (i.e. flashing new firmware that is beyond the control of your code).
 <note important>Please note cameras are running only with some 5-10fps so do not implement quick flashing light as you may not be able to observe it remotely. Same note applies to the quick changes of the LCD contents.</note>
 <note tip>Build in LEDs (both) are active with signal LOW so setting HIGH on GPIO 16 or 4 switches them off while setting LOW switches them on.</note>
+<note important>Even if 20x4 LCD displays look same in different nodes, nodes 8 and 9 use 0x3F address while nodes 10 and 11 use 0x27. Using invalid I2C address in your code causes the display to become inoperable.</note>
 ===== 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'']].
+==== LCD Display ====
 The LCD I2C control library can be imported to the source code via:
 <code c>
 #include <LiquidCrystal_I2C.h>
 </code>
-Then configure your LCD controller:
+Then configure your LCD controller for nodes 8 and 9:
 <code c>
 LiquidCrystal_I2C lcd(0x3F,20,4);  // set the LCD address to 0x3F
                                    // for a 20 chars and 4 line display
+                                   // Nodes 8 and 9
 </code>
+or for nodes 10 and 11
+<code c>
+LiquidCrystal_I2C lcd(0x27F,20,4); // set the LCD address to 0x3F
+                                   // for a 20 chars and 4 line display
+                                   // Nodes 10 and 11
+</code>
+==== Servo ====
+The easiest way to control a servo it is using a dedicated library. Still, low-level PWM programming is possible.
+<code c>
+#include <Servo.h>
-=== 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]
+#define servoPin D5
-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>
+<code d>
+Servo servo;
+servo.attach(servoPin);
+</code>
+==== Fan ====
+Fan operation is controlled via classical PWM. We control fan using ''analogWrite''. Suggested PWM frequency is about 250 Hz:
+<code c>
+  #define PWMFanPin D8
+  ...
+  pinMode(PWMFanPin,OUTPUT);
+  analogWriteFreq(250);
+  analogWrite(PWMFanPin,0); //stop FAN
+</code>
+<note important>Setting too high PWM frequency causes fan to operate binary (on/off) and limits controlling range.</note>
 ===== Communication =====
@@ Line 85: / Line 105: @@
 ===== Limits =====
-At the same time, only one user can be programming the controller, although analysing the signal by others (unlimited number) the user has sense. Model is provided to work continuously, without service breaks.
+At the same time, only one user can be programming the controller, although analysing the signal by others (unlimited number) the user has sense. ode does not require physical human interaction and is supposed to work continuously, without service breaks.
 ===== 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). Mind to use appropriate I2C address, regarding the node booked (nodes 8 and 9 are using 0x3F, nodes 10 and 11 use 0x27):
+<code c>
+#include <Arduino.h>
+#include <LiquidCrystal_I2C.h>
+LiquidCrystal_I2C lcd(0x3F,20,4);  // set the LCD address to 0x27 for nodes 10 and 11
+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/generalpurpose3.1587935756.txt.gz · Last modified: 2020/07/20 09:00 (external edit)