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--- en:iot-open:remotelab:sut:generalpurpose2:b7 [2020/07/20 11:26] – external edit 127.0.0.1
+++ en:iot-open:remotelab:sut:generalpurpose2:b7 [Unknown date] (current) – external edit (Unknown date) 127.0.0.1
@@ Line 8: / Line 8: @@
 === Prerequisites ===
-You need to understand how typical servomotor looks like and how it works.\\
+You need to understand how a typical servomotor looks like and how it works.\\
-The servo is controlled using predefined, precise PWM timing. Most servos share exactly the same model (0-180 degree servos), regardless of their size and power voltage. Classical, analogue servo frequency is 50Hz = 20ms period and duty cycle of the high signal is 1ms for 0deg and 2ms for 180deg. So changing the PWM duty cycle from 1ms to 2ms (5% to 10%) rotates servo. There is no need, however, to implement manually (still you can do) but you will use a predefined library instead of manually setting-up PWM. This brings features like range mapping to control servo logical way (i.e. providing angle, not duty cycle).\\
+The servo is controlled using predefined, precise PWM timing. Most servos share exactly the same model (0-180 degree servos), regardless of their size and power voltage. Classical, analogue servo frequency is 50Hz = 20ms period and duty cycle of the high signal is 1ms for 0deg and 2ms for 180deg. So changing the PWM duty cycle from 1ms to 2ms (5% to 10%) rotates servo. There is no need, however, to implement manually (still you can do it) but you will use a predefined library instead of manually setting up PWM. This brings features like range mapping to control servo logical way (i.e. providing angle, not duty cycle).\\
 The library is ''Servo.h''.
@@ Line 15: / Line 15: @@
 === Scenario ===
-In this scenario, you will rotate the servo to the 0 degrees, then 45, 90, 135 and 180 degrees counter wise, then 180, 90, 0, clockwise. Note - Arrow pointing left means servo is set to 0, pointing right is 180 degrees, and when 90 degrees, arrow points down.
+In this scenario, you will rotate the servo to 0 degrees, then 45, 90, 135 and 180 degrees counter wise, then 180, 90, 0, clockwise. Note - Arrow pointing left means servo is set to 0, pointing right is 180 degrees, and when 90 degrees, arrow points down.
-We use LCD to get feedback about requested servo angle and to compare it with the result, but please note, it is just for information only and is not necessary to implement servo rotation.
+We use LCD to get feedback about the requested servo angle and to compare it with the result, but please note, it is just for information only and is not necessary to implement servo rotation.
 <note warning>Please DO NOT use ''loop()'' to implement infinite servo rotation as it will wear out quickly and can even burn. Servo is NOT INTENDED to rotate as a motor. Instead, implement your code to run once or twice in the ''setup()'' function. You may reset the node to restart your code without the need to recompile.</note>
@@ Line 45: / Line 45: @@
 <code c>
 ...
-int angles[] = {0,45,90,135,180,90,0};
+byte angles[] = {0,45,90,135,180,90,0};
 ...
 </code>
@@ Line 53: / Line 53: @@
 <code c>
 ...
-LiquidCrystal_I2C lcd(0x3F,20,4);   // set the LCD address to 0x3F for nodes 1 through 5, 8 and 9 for a 20 chars and 4 line display
+LiquidCrystal_I2C lcd(0x3F,20,4);   // set the LCD address to 0x3F for nodes 1 through 5,
+                                 //8 and 9 for a 20 chars and 4 line display
 //LiquidCrystal_I2C lcd(0x27,20,4); // for nodes 10 and 11 only!
 ...
@@ Line 71: / Line 72: @@
 ...
 </code>
-Setting servo to desired angle is as simple as calling ''servo.write(angle);''. Default mapping is 0...180 degrees for micro servos we use here.
+Setting servo to the desired angle is as simple as calling ''servo.write(angle);''. The default mapping is 0...180 degrees for micro servos we use here.
 \\
@@ Line 81: / Line 82: @@
 ...
 </code>
-The ''sizeof'' operator above brings you automated evaluation of the array size during compilation, thus if you add or remove an item(s) from the array in the declaration section, loop will automatically change iteration scope, according to the new array size.
+The ''sizeof'' operator above brings you an automated evaluation of the array size during compilation, thus if you add or remove an item(s) from the array in the declaration section, the loop will automatically change iteration scope, according to the new array size.
@@ Line 87: / Line 88: @@
 == Step 5 ==
-Keep ''loop()'' dummy, empty method not to overheat the servo or to wear out it's gears:
+Keep ''loop()'' dummy, empty method not to overheat the servo or to wear out its gears:
 <code c>
 ...

en/iot-open/remotelab/sut/generalpurpose2/b7.1595244387.txt.gz · Last modified: 2020/07/20 09:00 (external edit)