[gandalf1]

Hi Steve,
Here on the edge of the East Angular Fens we may sometimes get a little muddled. Buzzing around in my head was something about only being able to divide in multiples of two anyway you have set my mind at rest so I'll now start making bits. First since it is easiest an adaptor to connect my motor to the little home made dividing head and then on to the circuit board.
Thanks for your valued assistance on the project.
John.

[gandalf1]

Hello again Steve,
A thought occurred to me about the uses for your controller. I searched the documentation as best I could but although and found there is a continuous running command. Is it at all posssible to add or is it already included a command for a number of output turns. I have in mind something to instruct say a milling machine to move the table a set distance which would require a number of turns rather than continuous rotation. Maybe I have got it wrong but it would be useful for me to be able to move lathe saddle or crosslide, mill table or even adapt the bench drill pre-determined distances.
Sorry to be a pain yet again.
John.

[kwackers]

Hi John,

There's no trivial function to do that, you may be able to use the program mode to 'hack' something.
One of the biggest issues is the calculation of distance - you'd need to be able to figure out what the displayed angle meant in terms of distance. It may be possible to arrange gearing so that 360.0 was 360mm or 36 inches etc. You'd also then have to watch out that it didn't 'loop' - i.e. because it assumes it's driving a rotary table it thinks it can get to (say) 1.0 from 350.0 by moving forward another 2.0 units...

In simple terms it was only ever designed to replace a set of dividing plates and being digital it can divide quite happily by any and every value from 1 to 9999 (including primes).
Whilst there are many possibilities for a linear version, the work I've done on looking into it shows it to be a much more complex area requiring a fair bit of my time to get anywhere with. I do have software partly written for a linear version but currently just don't have the time to do much on it.

Regards
Steve.

[Khalid]

Steve,Excellent programming and electronics combination... You must be proud of your inventions..and utilizing your skills can make you do some unbelievable projects..You are the man...

[Khalid]

Steve,
All things are working fine here except a minor issue... My LCD display is blinking (The backlight LED) .. This causes bad effect on display, however display is very good readable... Did you program the LCD like this?.. Is it the Refresh rate or something i have to adjust the POT?
Regards

[kwackers]

Hi Khalid,

The backlight for the LCD has nothing to do with the controller. It's simply fed from a resistor ("Backlight" on overlay - not shown on circuit diagram) via the 5v line.

If it's flashing, then I'd think it's either not intended to be run from 5v via the resistor or there's a fault with the LCD.
If you have the datasheet for the LCD you purchased, might be worth looking at that to see if it can cast any light on the issue, failing that swapping the LCD is all I can suggest.

Regards
Steve.

[Khalid]

Thanks Steve,
I am using LMB204BFC Lcd display from Topway.. Attached is the spec. sheet..Can you please help me resolve the problem?

I am using 2.11 Firmware and all the functions working perfect..The only problem is flashing of LED's of LCD...

[kwackers]

I can't see anything unusual about the display, looks pretty normal. (The backlight circuitry looks as if it might have it's own current limiting resistors already).

The only thing I can suggest is separating out the backlight supply. Disconnect pins 15 & 16 and run them through a new resistor to the power coming into the board.

Your docs show a vFwd for the backlight of 5v and a max current of 80mA. If we limit the current to say 50mA to be on the safe side then we can calculate a resistor (ignoring the resistors shown since we don't know what they are).

Using the formula R = V/I, where V is the supply voltage minus 5 and I is the 50mA.

So say your supply is 24v, then R = (24 - 5) / 0.05 = 19 / 0.05 = 380 ohms (or nearest value you can find).

Bear in mind power loss in the resistor is given by P = V*I, or 19 * 0.05 = 0.95W
So the resistor would need to be at least 1W.

[redpiperbob]

Hi Kwackers
can you tell me if the K8076 - PIC Programmer Board KIT can programme the pic 18f452 chip. I have emailed the makers but have had no reply. While I am on thank you for all your hard work.
Bob

[Khalid]

Thanks Steve for advice and calculating the resistor value...,
I will try to install new resistor and will show you the results...
I am using 12Volt logic supply (Resistor: R140 1/2Watt)to your controller and will use Gecko 203V drive with seperate supply 48V to run a stepper motor 600 Oz-in 4A 1.8 degree per step.. I dont know how the G203V will handle the step and direction signal from rotary indexer controller.... This is because the G203V itself has specially designed 10microstep and i dont know how will it behave...

[kwackers]

@redpiperbob. I'm afraid I know no more than you, I googled it but the 452 isn't shown in it's list of supported devices so may be best to assume not.
There are many cheap programmers available on eBay (usually from the far east) that are available (search for "JDM programmer").

@Khalid
Just one point with regards your driver, the maximum number of steps my controller can issue per full revolution of the table is 65535. When microstepping you may find the number of microsteps required to rotate the table exceeds this. I would advise only using half stepping if it's available. For this application there is nothing to be gained by microstepping.

[Khalid]

Hi Steve,
by reading the following document of Mariss its confusing... It seems that with different speed the G203V changes microstep..At a specific speed it runs in full step mode while in low speed it runs in microstep.. a difficult archetecture
http://www.geckodrive.com/upload/How...your_motor.pdf

[kwackers]

Unless I'm misunderstanding the documentation it sounds like the driver 'chooses' whether to microstep or not itself based on the motor speed. If this is the case the microstepping is internal to the driver and shouldn't matter to the controller.

You'll still need to know how many steps constitute a single rotation though. The motors are usually 200 steps per RPM (multiplied by your reduction/worm ratio), in half step mode (what I'd usually use) they're 400.

[redpiperbob]

Thanks Steve JDM ordered
Bob

[Khalid]

Steve,
My Indexer is 12inch with 40:1 ratio.. The motor is 200 steps and as i know from your FIRMWARE 2.11, this should be 400...

So if i am not doing wrong :
My settings will be: 4000steps for one full rotation?

My very regards to you steve..

[kwackers]

4000 is correct

[redpiperbob]

Hi Steve
I etched a board for your rotary table indexer. But it has not come out too well my problem is that i only have the iron-on material to stick to the board and your board is too fine a detail for the material. (or maybe I'm doing it wrong) So I was wondering if you ended up making the boards for this project.
and if so could I purchase one.
Thanks Bob

[redpiperbob]

Hi Steve
I etched a board for your rotary table indexer. But it has not come out too well my problem is that i only have the iron-on material to stick to the board and your board is too fine a detail for the material. (or maybe I'm doing it wrong) So I was wondering if you ended up making the boards for this project.
and if so could I purchase one.
Thanks Bob

[redpiperbob]

sorry about the double post
Bob

[kwackers]

Hi Bob,

I was going to make up some PCB's, but having just been made redundant all my efforts are currently going into drumming up work.

If anyone else fancies having some made up then by all means feel free. I know there are people on other forums who would like some. I'd estimate there are an easy 20 or so people out there who want one - almost certainly more if they where made available and advertised on the forums.

As an aside thanks to Marty E (and friend) for getting the code working on 18f4520. As soon as I've checked the code I'll post up an elf for that chip (for anyone having problems picking up 452's).

Steve.