Arduino Servo Point Motor Control

Now looking on the web - where else these days, I found the DCC++ project

https://github.com/DccPlusPlus/BaseStation/blob/master/README.md

This uses an Arduino UNO or MEGA plus the Arduino motor shield to form the base station, in addition JMRI now has support for the DCC++ system. By using off the shelf shields no soldering is required, but does work out dearer than building your own.

Communication between a PC and the Arduino is via a serial connection (USB port) or via blue tooth (provided a bluetooth adapter is fitted).

JMRI would give an easy way of producing a mimic interface, and also routing.

DCC++ also has its own software application, primarily aimed at running trains, but also can make a mimic panel and operate accessories.

For those already having DCC, this be able to make a standalone programming track.

I know you could use the MERG Command station kit, or a Sprog,

Paul

 

With JMRI, you can use either the throttles on the computer screen, or via the appropriate app (engine driver for android) use mobile phones as wireless throttles.

They do work very well, and can have multiple throttles running on each device - I've found more than two locomotive throttles open on a device becomes awkward. The application also has access to the mimic panel, turnout tables and routing tables, so you can fully control your layout from a phone or tablet.

JMRI support for DCC systems can be found here

http://jmri.sourceforge.net/help/en/html/hardware/index.shtml

MRC (Gaugemaster is a rebranded MRC system), have only recently released the specifications to allow the JMRI teams to develop support, so can have issues or features missing compared to other systems, but I'm sure will catch up. The same can also be said for DCC++ as it is a relatively new system, however being an open system has allowed developers complete access to the system and features / functionality are catching up with the other systems.

And for what we are looking at is more than capable.

Paul

 

Back on track now......

I think the DCC for DC topic should go on its own thread, so I will create one.

A question no one asked was how do you know what to set the off and on angles to ?

servos[1].address = 2;
servos[1].outputPin = 13;
servos[1].servo.attach(4);
servos[1].offangle = 112;
servos[1].onangle = 62;

Well Ruud Boer comes to the rescue again.

Within his Arduino_DCC_S88 download is a servo tune utility.

Servo Tune v3.0
Ruud Boer
April 24, 2015

Can tune one servo at a time.
Uses 2 setpoints: min, max

Use a wire or switches to make A0 - A3 LOW.

A0 = select max angle setpoint, CCW (looking at axle)
A1 = select min angle setpoint, CW (looking at axle)
A2 = increase angle, CW
A3 = decrease angle CCW

So I will make up this one using an arduino UNO, as per Ruud's instructions.

Paul

 

Early on in this thread Reidy asked how do I know what to connect to the arduino.

For Sketches / projects that are done correctly, the introduction should make all clear.

As for this sketch - as normal Ruud does an excellant job.

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Ruud Boer April 24, 2015
// DCC Servo Tune v3.0
//
// PURPOSE: Tune the angles of 2 setpopints of servos.
// Values are shown on Serial Monitor to be (manually) transferred to DCC_Decoder_Servo.
//
// CONNECT THE SERVO TO PIN 3
//
// REMARK 1: when looking at the axle of the servo, CW = lowe angle values, CCW = higher angle values.
//
// REMARK 2: Timing for Servo, Setpoint and Print can be changed in lines 37,38,39.
//
// REMARK 3: To avoid servo movement which can give high current draw at startup,
// first start the Arduino and after led blinked 5 times switch the servo power on.
// Before power down, move the servo to setpoint 1 = CCWidle.
//
// OPERATION:
// A0: Select setpoint 0 MAX angle, CCW (looking at axle)
// A1: Select setpoint 1 MIN angle, CW (looking at axle)
// A2: Increase angle of current Setpoint, CCW
// A3: Decrease angle of current Setpoint. CW
//
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

From the above Pin D3 will connect to the servo signal wire (the +5V and 0V will connect direct to the 5V power supply with possibly an off/on switch added) & four switches will be required which will be connected Analog ports A0 to A3.

The arduino will also be connected to a PC via its usb cable to display the values.

These values will then need to be manually added to the servo controllers sketch and uploaded to the servo controllers arduino.

Will post more later - my services are required by SWMBO and Spawn of SWMBO

Paul

 

Ok

In its basic form, all I needed to make this was

1 x Arduino UNO
1 x SG90 servo
4 x jumper wires
1 x USB cable connected to the PC running the Arduino software

The sketch was loaded into the arduino via the usb cable, the cable is also providing the power supply - some PC usb ports may not be able to power the arduino and the servo, and a separate 5V power supply will be needed.



Vin (white wire) is connected the positive wire for the servo.
Gnd (black wire) is connected to the 0V or ground of the servo
Gnd (grey wire) is used to insert in either A0, A1, A2 or A3 to act as a switch



The orange wire is connected to D3 and the servo signal wire.

On start up the sketch sets the servo to mid point.

The serial monitor window needs to be started, which will also restart the sketch.

The serial monitor will then output the current settings



By connecting A0 to ground the sketch will make adjustments to max position

then by connecting either A2 or A3 to ground will adjust the position either clockwise (A2) or anti-clockwise (A3).

Once the final position is determined, connect A1 to ground to carry out the same for the min position.

Even keeping the connection in the movement is slow so it is easy to get the setting correct.

Simples



Take note of the final settings and enter the values into the DCC_servo sketch.

Paul

 

Hi Col

My two current layouts - Victoria Road, and Gasworks layout, will only use 10 servo's between them, but as this circuit is so simple, I'm going to see what would be needed to complicate it up a bit

Thinking of adding an lcd screen, switches and a battery for power to make a portable unit, well see........

Paul

 

mmmm looks like I've got a bit of reading to do

Thanks for the link

Paul

 

mmmmmm even better, well impressed.