VelTek shield motor step - Revision history

Andb: /* Problems?? */

2019-09-25T11:48:00Z

Problems??

Andb: /* Usage */

2019-09-25T11:47:24Z

Usage

Andb: /* Usage */

2019-09-25T11:41:39Z

Usage

Andb: /* Setup */

2019-09-24T12:09:02Z

Setup

Andb: /* Setup */

2019-09-24T12:04:59Z

Setup

Andb: /* Setup */

2019-09-24T12:03:40Z

Setup

Andb: /* Getting started */

2019-09-24T11:34:16Z

Getting started

Andb: /* Required software */

2019-09-24T11:29:51Z

Required software

Andb: /* Software description */

2019-09-24T11:25:36Z

Software description

Andb: /* Serial commands */

2019-09-24T11:05:19Z

Serial commands

@@ Line 77: / Line 77: @@
 == Problems?? ==
-* Problem: The numbers in the first column (motor angle) never changes, or can only increase.
+* '''Problem:''' The numbers in the first column (motor angle) never changes, or can only increase.
-** Solution: The encoder signals (purple and orange wire) are probably not connected correctly. They should connect to the pin directly next to the little grey wire. Click on the close-up picture of the board to view it in large format and double check all connections.
+** '''Solution:''' The encoder signals (purple and orange wire) are probably not connected correctly. They should connect to the pin directly next to the little grey wire. Click on the close-up picture of the board to view it in large format and double check all connections.
 = Hardware description =

← Older revision		Revision as of 11:47, 25 September 2019
Line 74:		Line 74:

	Interresting functions for creating a feedback control system could be '''motor.getMotorPositionAngle()''' and '''motor.getDeltaMotorPositionAngle()'''. You find available functions declared in the header file '''VTMotorControl.h'''.		Interresting functions for creating a feedback control system could be '''motor.getMotorPositionAngle()''' and '''motor.getDeltaMotorPositionAngle()'''. You find available functions declared in the header file '''VTMotorControl.h'''.
		+
		+	== Problems?? ==
		+
		+	* Problem: The numbers in the first column (motor angle) never changes, or can only increase.
		+	** Solution: The encoder signals (purple and orange wire) are probably not connected correctly. They should connect to the pin directly next to the little grey wire. Click on the close-up picture of the board to view it in large format and double check all connections.

	= Hardware description =		= Hardware description =

@@ Line 61: / Line 61: @@
 == Creating velocity feedback ==
-Every line of code inside the Arduino function '''void loop()''' (bottom of Arduino sketch file veltek-shield-motor-ab-encoder.ino) will be executed repeatedly as fast as possible, but we don't have any control over exactly how fast. This is bad for control systems where we want to know the sample rate in Hz. An easy fix is to create a function that can measure if a fixed amount of time has passed. This is exactly what '''checkTime()''' does. It returns true if 20 ms (or more) has passed and false otherwise. You can find this '''if(checkTime())''' statement in the void loop() function:
+Every line of code inside the Arduino function '''void loop()''' (bottom of Arduino sketch file veltek-shield-motor-ab-encoder.ino) will be executed repeatedly as fast as possible, but we don't have any control over exactly how fast. This is bad for control systems where we want to know the sample rate in Hz. An easy fix is to create a function that can measure if a fixed amount of time has passed. This is exactly what '''checkTime()''' does. It returns true if 4 ms (or more) has passed and false otherwise. You can find this '''if(checkTime())''' statement in the void loop() function:
   if(checkTime())
@@ Line 70: / Line 70: @@
+  }
-This is responsible for printing out the two columns of numbers (position in milli radians and motor voltage) at a rate of 50Hz (20ms period).
+This is responsible for printing out the two columns of numbers (position in milli radians and motor voltage) at a rate of 250Hz (4ms period).
 If you want to create a feedback system, you can add code here to calculate an error, multiply it with a gain, and feed it to '''motor.setMotorVoltageMilliVolt()'''.

← Older revision		Revision as of 12:09, 24 September 2019
Line 41:		Line 41:


−	'''Note:''' Make sure that you connect the 12V adaptor to your Arduino board before connecting it to your computer via USB.	+	<span style="background:orange">'''Note:''' Make sure that you connect the 12V adaptor to your Arduino board before connecting it to your computer via USB.</span>

	= Usage =		= Usage =

@@ Line 30: / Line 30: @@
 = Setup =
 [[File:IMG_motor_cable_mounted.jpg|200px|float|thumb|motor encoder cable mounted correctly]]
-[[File:IMG_arduino_motor_shield_connected_v2.JPG|200px|float|thumb|motor connected to VelTek shield]]
+[[File:IMG_arduino_motor_shield_connected_v2.jpg|200px|float|thumb|motor connected to VelTek shield]]
 # Mount VelTek shield on top of Arduino. Take care that all pins mate correctly to their sockets before pressing together.
 # Connect motor cable to DC motor. The little white plug can only go in one way. When inserted correctly, the orange wire is towards the edge of the circuitboard. (See picture)

@@ Line 49: / Line 49: @@
 To test that motor and encoder works, try to turn the motor axel by hand. You should see the number in the first column increase og decrease. The number is motor position in milli radians (6283 milli rad / turn)
-Click on the text box in top of the serial monitor window, type a single digit from 1-9 and press enter. The motor should start turning. 1 is the lowest speed (voltage), 9 is max voltage (12 V = 12000 mV). Type 0 and enter to stop the motor (0 V)
+Click on the text box in top of the serial monitor window, type the string "v5000" and press enter. The motor should start turning. The number is voltage in millvolt (12 V = 12000 mV). Type "v0" and enter to stop the motor (0 V)
 == Serial commands ==

@@ Line 24: / Line 24: @@
 * Serial terminal program with logging capabilities. We recommend [https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html Putty] which is available on Windows/Linux/Mac.
 * Math program capable of importing numbers from a text file. Matlab or [https://www.gnu.org/software/octave/download.html Octave] (free) is recommended, but Microsoft Excel can also be used.
-* Arduino sketch (C/C++ program for the Arduino) [[File:Veltek-shield-motor-ab-encoder-1.0-beta1.zip]] that starts the DC motor and count pulses from the encoder on the motor.
+* Arduino sketch (C/C++ program for the Arduino) [[File:Veltek-shield-motor-ab-encoder.zip]] that starts the DC motor and count pulses from the encoder on the motor.
 :'''Important:''' After unpacking the .zip file, make sure that the folder name is the same as the .ino file name inside. E.g.: '''veltek-shield-motor-ab-encoder'''.
 * [https://www.arduino.cc/en/Main/Software Arduino IDE] to compile and upload the sketch to your Arduino. This is available on Windows/Linux/Mac

@@ Line 86: / Line 86: @@
 :Main sketch file with the two important Arduino functions '''setup()'''  and '''loop()''' plus some extra utility functions to help the system measure and keep sample time and read user input/commands form the serial port.
-;VTMotorControl.cpp
+;VTMotorControl.cpp (and .hpp)
 :Implementation of the motor control functions
-;VTMotorControl.hp
+;VTSerialParser.cpp (and .hpp)
-:Header file for VTMotorControl.cpp class
+:Helper functions that converts a received number on the serial port to an integer.
 ;VTShieldPins.h
 :Pin and signal definitions for VelTek shield.

@@ Line 58: / Line 58: @@
      u<n> -where n is the desired wave form amplitude upper value in millivolt. Range: -12000 >= n >= 12000
      l<n> -where n is the desired wave form amplitude lower value in millivolt. Range: -12000 >= n >= 12000
-     t<n> -where n is the desired wave form type. 1=sine, 2=triangle
+     t<n> -where n is the desired wave form type. 1=sine, 2=triangle, 3=step function
 == Creating velocity feedback ==