Let's Get The Show On The Road......

[Garfield2]

Originally Posted by santiniuk Can someone confirm the value of Resistors R1-R5 on the interface board. They look like pull-ups.

Indeed, they're 10K. Just a normal pull-up resistor

Originally Posted by santiniuk Also the switches, I'm not entirely sure what all 14 are required for. Can someone please clarify ?

The 2x2 blocks are for setting the modes of the controllers (Full, Half, 1/4, 1/8th), they're just jumper blocks. The other six are just general inputs for home switches etc. If you don't need them you can just leave them out along with the pull-up resistors. The "CONN7" block is an output block for 3 pins on the parallel port which you can use to trigger your own relay drivers to turn on/off motors/pumps/routers.

Originally Posted by santiniuk Lastly on the control boards I have some 470pf caps instead of the 500pf specified will these be ok ?

470pF will be fine to replace the C2/C4 capacitors. The only critical value there is the 2.2nF's of C1/C3 as they set the RC up for the PWM timing.

Also ignore the error in the schematic for the values of R2/R4 these two resistors set the current limit for each coil and should be set the same using this equation to work out their values :-

resistor value = 20000 / coil current

eg 20000 / 0.7A = 28K


The interface board uses the same screw terminal block of the controller boards. The 2x2 are just 2x2 IDC pins.


Cheers,
Alan.

PS quite busy organising new infrastructure at work, so I cannot monitor these forums or my email for the next few weeks. Thanks.

[santiniuk]

As always help when needed. Thank's guy's.

I appreciate the assistance.

Cheers

[BobLWeiss]

I used a 470pf cap as well. I cannot find a 500pf cap anywhere and believe me I looked. I don't belive they make one. It should be ok.

The 5 resistors are pullups for the external input switches. The reason for so many is because the lines are available so why not use them? (I'm guessing). I am using them for home and limit switches.

[santiniuk]

Not guite 100% but nearly there....

Missing a couple of components but got all 4 boards built to 99%

Not going to have a chance to do much this weekend so it will be Monday before much more is done.

I have the bits to make the IDC leads and will make these on Monday.

I messed a bit with my camera trying to get some decent pic's. Not great, maybe when you have some time Alan you can give a few pointers on how to get good closeup shots.

I must dust off the boards before I take pics next time
Cheers,

[BobLWeiss]

Looks good...your pictures are fine the way they are now.

I am at the same stage as well..they messed up my order so I have to wait till Monday to get the rest of my parts...its a race to see who's done first...

Bob

[Garfield2]

Originally Posted by santiniuk Not guite 100% but nearly there.... Missing a couple of components but got all 4 boards built to 99% Not going to have a chance to do much this weekend so it will be Monday before much more is done. I have the bits to make the IDC leads and will make these on Monday.

Looks excellent. Making massive progress! Well done.

Originally Posted by santiniuk I messed a bit with my camera trying to get some decent pic's. Not great, maybe when you have some time Alan you can give a few pointers on how to get good closeup shots.

Unfortunately it's called a really expensive camera and a really good 35mm lens. I have a Canon 10D and I used a Canon EF 28mm f/1.8 lens. But! you can get really good results with everyday digital cameras. My mate Dan has written a very good basic photographic tutorial at :

http://www.dansdata.com/

Originally Posted by santiniuk I must dust off the boards before I take pics next time Cheers,

Guilty of that too!



-A

[BobLWeiss]

Just to make sure I read your code right, whats the four jumper settings for the modes? I mean what is both off, both on, left on & right off (looking at the board from the top with the parallel port to the bottom) & finally right on & left off?

Thanks

[Garfield2]

Originally Posted by BobLWeiss Just to make sure I read your code right, whats the four jumper settings for the modes? I mean what is both off, both on, left on & right off (looking at the board from the top with the parallel port to the bottom) & finally right on & left off? Thanks

From memory it's like this :-

00 - 1/8th
01 - 1/4
10 - 1/2
11 - Full

(or it could be the reverse. you can change it easily enough while the drivers are running if you wish. It's pretty obvious which is which, hence why I cannot remember)

-A.

[Garfield2]

Originally Posted by santiniuk Not guite 100% but nearly there....

One thing I noticed with your pictures is that you've soldered in the current setting resistors in place. Did you mean to do this?

I normally use the inner of a round pin IC-Socket so I can push the legs of the resistors into place and replace/change them easily. Unless you extremely happy with your load setting straight up that's fine to solder them in.

When I first powered up my drivers I had my motors driven with like 100mA just so I could get a feel for what the drivers where doing before I juiced them to 1.5A.

Just an idea.

[BobLWeiss]

Yeah I used a breakable female header strip and just soldered 1 pin into each of the resistor holes on the pc so I could change the resistors easily down the road. I am not sure what current I want to drive the motors with either at first.

[santiniuk]

Thanks for the feedback folks. It's certainly the incentive to keep going.

Bob I too was going to post a query on the jumper settings but you beat me too it. Let the race begin

Dan's photographic tutorial is a good read, I like the writing style. Will put some of his tips into action on the next pic's.

Looks like I was caught out on the current setting resistors. I noticed this after the boards were built. Will swap these for some socket's.

I intend to try the 20 Mhz Crystals on Monday with two 27pf cap's from each leg down to gnd. Hopefully this will work. Will I need to change any config bits during the programming stage of the micro ? Not too sure on that.

I made a few notes when putting the pcb's together and marked up Alans image. On my pcb's the pads highlighted in red were almost merged into the track.There is very little clearance. The pads marked in blue are just about usable after being drilled for the connector. Maybe a bigger pad is required for home etching.

That's it I have one stepper motor to try out that has 8 wires. R.S components part number 440-470. I better see how this converts to a 4 wire device now.

Cheers,

[BobLWeiss]

What size bit are you using for drilling? I used a 56 for most of the board and there is adequate room for soldering. I had to use a bigger bit for the ic's and screw terminals.

As for using a crystal instead of a resonator, you don't have to change anything with the code or config bits.

I am too going to be trying a 8 lead stepper.