Arduino focus control for DC AND stepper motors?

[michaelmorris]

Well, all the basic bits a have arrived and I've put it together. I've uploaded the firmware to the board and downloaded the ASCOM drivers and software to my computer  ... 

[michaelmorris]

It works!!! 

 

Next I need to order the buttons for manual control , sort out a 9v power supply and put it all in a case. 

Edited January 6, 2017 by michaelmorris

[Dr_Ju_ju]

for the 9v supply, get a bucky converter http://www.ebay.co.uk/itm/LM2596-DC-DC-Switching-Adjustable-Step-Down-Voltage-Regulator-Converter-3V-40V-/172058668488?var=&hash=item280f7eedc8:m:mDHLwFGVrh49Tb7BA-Y6CWg & run it from your 12v supply

[michaelmorris]

7 hours ago, Dr_Ju_ju said:

for the 9v supply, get a bucky converter http://www.ebay.co.uk/itm/LM2596-DC-DC-Switching-Adjustable-Step-Down-Voltage-Regulator-Converter-3V-40V-/172058668488?var=&hash=item280f7eedc8:m:mDHLwFGVrh49Tb7BA-Y6CWg & run it from your 12v supply

Thanks

[michaelmorris]

The push buttons have now arrived so that I can operate the focuser when I'm next to the scope.  I've read through the myDCFocuser documents and I can't for the life of me work out where to wire them in. Help!

Please bear in mind that I am to electronics what Jack Nicholas was to Greco-Roman wrestling!

Edited January 13, 2017 by michaelmorris

[brown_rb]

They wire to A0 as shown in circuit diagram :-)

[michaelmorris]

2 minutes ago, brown_rb said:

They wire to A0 as shown in circuit diagram :-)

Thanks Rob

I get parts of the diagram, but other bits are a bit of mystery to me.

There are 3 x 1.2Kohm resistors and a 1Mohm resistor in the circuit and one end of the circuitis  attached to the 0 (Marked RXC) terminal on the Arduino. Is this correct? 

Do the other ends of the circuit attach to the 5v and one of the GND terminals on the Power section of the Arduino?

Also, what is the triangle of three lines of diminishing size symbolise?

Sorry for the numpty questions, but I'm more or less a complete newbie at his.

[brown_rb]

4 hours ago, michaelmorris said:

Thanks Rob

I get parts of the diagram, but other bits are a bit of mystery to me.

There are 3 x 1.2Kohm resistors and a 1Mohm resistor in the circuit and one end of the circuitis  attached to the 0 (Marked RXC) terminal on the Arduino. Is this correct? 

Do the other ends of the circuit attach to the 5v and one of the GND terminals on the Power section of the Arduino?

Also, what is the triangle of three lines of diminishing size symbolise?

Sorry for the numpty questions, but I'm more or less a complete newbie at his.

 

[brown_rb]

I guess the sawtooth lines represent a resistor.

There are 4 resistors, 3 at 1.2K ohms and 1 at 1MegOhm

There are 2 switches (probably has 3 pins, one pin in the center - if there are only 2 pins this is fine) .

Take the first 1.2k resistor and we will call it R11. Wire one end to the resistor to 5V on the arduino.

Take the next 1.2k resistor and we will call it R12. Wire one end of the resistor to GND on the arduino.

Take the next 1.2k resistor and we will call it R13. Wire one end to the spare end of R11. We will call this join R11/R13.

Take the spare end of R13 and wire it to the spare end of R12. We will call this join R13/R12.

Solder a wire from the Join R11/R13 to the center pin of switch1 (if switch1 only has 2 pins wire the Join R11/R13 to any pin of Switch1).

Solder a wire from the Join R13/R12 to the center pin of switch2 (if switch2 only has 2 pins wire the Join R11/R13 to any pin of Switch2).

Solder the remaining free pin on Switch1 to the remaining free pin on Switch2. We will call this join S1/S2. Take one end of the next resistor 1M-Ohm which we will call R10 and wire one end to this join S1/S2.

Take the spare end of the R10 resistor and solder it to the GND on the Arduino.

Solder one end a wire to the Join S1/S2 and the other end of the same wire to A0 (Analog Pin 0) of the Arduino.

 

 

Edited January 14, 2017 by brown_rb

[michaelmorris]

Thanks ?

[SonnyE]

8 hours ago, michaelmorris said:

The push buttons have now arrived so that I can operate the focuser when I'm next to the scope.  I've read through the myDCFocuser documents and I can't for the life of me work out where to wire them in. Help!

Please bear in mind that I am to electronics what Jack Nicholas was to Greco-Roman wrestling!

Everybody starts somewhere Michael. Take heart, at this point you are ahead of me.

[brown_rb]

[SonnyE]

Michael and RB,

Here is a link to some basic symbols you are encountering as you slowly sink into the mire of electronics.

http://www.electronic-symbols.com/electronic-electrical-symbols/basic-electrical-electronic-symbols.htm

I'm on my way to an electronic focuser as we speak. Parts on order as of today. I just needed a few confirmations from a friend who is using complete remote on his set-up in frozen North Dakota, U.S.A. One thing I changed about my plans is to go with a direct drive to my fine focus adjuster on my two-speed Crayford. I was concerned about the side loading a belt drive might impart to the tiny shaft (2.7 mm). Matthew (N.D.) has his direct coupled to his fine adjust shaft and assured me the tiny Unidirectional gear motors have plenty of torque to do the adjusting. So the side loading became a non-issue.

The motors I ordered are the 28byj 48, 5 volt, with Uln2003 Driver Board for Arduino. Same format as my friend has on his focuser.

Onward! Into the fog!

[michaelmorris]

7 minutes ago, SonnyE said:

Michael and RB,

Here is a link to some basic symbols you are encountering as you slowly sink into the mire of electronics.

http://www.electronic-symbols.com/electronic-electrical-symbols/basic-electrical-electronic-symbols.htm

I'm on my way to an electronic focuser as we speak. Parts on order as of today. I just needed a few confirmations from a friend who is using complete remote on his set-up in frozen North Dakota, U.S.A. One thing I changed about my plans is to go with a direct drive to my fine focus adjuster on my two-speed Crayford. I was concerned about the side loading a belt drive might impart to the tiny shaft (2.7 mm). Matthew (N.D.) has his direct coupled to his fine adjust shaft and assured me the tiny Unidirectional gear motors have plenty of torque to do the adjusting. So the side loading became a non-issue.

The motors I ordered are the 28byj 48, 5 volt, with Uln2003 Driver Board for Arduino. Same format as my friend has on his focuser.

Onward! Into the fog!

Thanks for the link. I wish you well with your project.

[SonnyE]

46 minutes ago, michaelmorris said:

Thanks for the link. I wish you well with your project.

And you with yours, Michael.

My parts are scheduled for next Monday. I hate the waiting... Sigh!

[michaelmorris]

The resistors arrived yesterday.  I followed Robert's excellent and clear step by step (i.e. idiot proof) instructions and wired it all up using patch cables and a breadboard.  And for the moment of truth ...

It works!!!!!! 

 

Thanks Robert, you are a true hero! 

Next to arrive is the 12v to 9v thingy, then put it all in a box.

 

[brown_rb]

Highly recommend you replace the push buttons with these - they are as solid as a rock and work significantly better

http://www.ebay.com/itm/6Pcs-Mini-12mm-Waterproof-Momentary-ON-OFF-Push-Button-Round-Switch-/201538126654?hash=item2eec9bc33e:g:PAEAAOSwvgdW4C4V

Congrats on getting it working.

[michaelmorris]

2 hours ago, brown_rb said:

Highly recommend you replace the push buttons with these - they are as solid as a rock and work significantly better

http://www.ebay.com/itm/6Pcs-Mini-12mm-Waterproof-Momentary-ON-OFF-Push-Button-Round-Switch-/201538126654?hash=item2eec9bc33e:g:PAEAAOSwvgdW4C4V

Congrats on getting it working.

Thanks for the tip.

[michaelmorris]

I've just order a small 9 x 20 Vero stripboard for producing the permanent circuit for the buttons.

[michaelmorris]

Are the R10 and R11 resistors shown in the myDCfocuser guide the potentiometers for manually altering the pulse interval and length?

If yes, will cheap 10kohm potentiometers from Ebay do, or is there a specific type or make I should be looking to get or avoid?

Thanks

Edited January 18, 2017 by michaelmorris

[brown_rb]

Yes 10k pots, any will do.

http://www.ebay.com/itm/2Pcs-10K-OHM-Linear-Taper-Rotary-Potentiometer-B10K-Pot-Knob-XH2-54-Wire-Cable-/191941882370

 

[michaelmorris]

5 hours ago, brown_rb said:

Yes 10k pots, any will do.

http://www.ebay.com/itm/2Pcs-10K-OHM-Linear-Taper-Rotary-Potentiometer-B10K-Pot-Knob-XH2-54-Wire-Cable-/191941882370

 

Thanks again.

[michaelmorris]

I'm now investigating the best way for me to physically mount all this electronics hardware.

For me, I think the best set up might be to put the Arduino and driver board in one box attached to the mount head.  This would include connections for 12v power, USB and the control/power cables going to focuser motors.  Connected to this would be a separate small box used as a hand controller.  This would include potentiometers and momentary switches, along with related resistors.  Hopefully, this hand controller could be re-used when I eventually upgrade to stepper motors and a stepper motor control board (using MyFocuserPro2).  Does this sound sensible?

If the above is a feasible idea, I would need at least five wires between the hand controller and the Arduino in the main box (5v, ground and three signal cables).  I assume this could be best achieved by using a single multicore cable between the hand controller and the main box.  I would propose using a DE9 (RS232-type) connector to attach the hand controller to the main box.  Is this the best option?  If yes, can anyone recommend the most suitable multi-core cable for this connection lead?

Thanks

Edited January 19, 2017 by michaelmorris

[SkyBound]

I would use a 6p6c modem type cable, which has 6 cores, (flat telephone cable) with the 6pin rj11 plugs on either end, it will make it much lighter, than using serial type sockets and cables.

thats what my Feathertouch motor focuser uses....

[SkyBound]

 Here are the plugs:

http://www.ebay.co.uk/itm/5-PACK-RJ11-RJ-11-Plugs-6-Core-6P6C-for-Telecom-and-ADSL-VDSL-Cable-/272399061897?hash=item3f6c3fd389:g:dYoAAOSwPCVX8WKg

and here is the cable:

http://www.ebay.co.uk/itm/ADJUSTAMATIC-BED-6P6C-RJ12-CABLE-6-WIRE-RJ-1m-2m-3m-4m-5m-/232192412553?var=&hash=item360fbf0b89:m:mwRYDfiwbkUpmCLVG9xGEoA

and the board mounted sockets

http://www.ebay.co.uk/itm/RJJ66NFRA-Mbs-Connect-Rjj-Socket-6P6C-Unshielded-Ra-/132062128153?hash=item1ebf842819:g:-UQAAOxyOalTa35X

 

Edited January 19, 2017 by SkyBound