[pigifly]

With a gnd on JP1(3):
a) pin 1 of the 40106 s/b less than .2volts reading 0V
b) pin 2 s/b greater than 3.5V, reading 4.92V
c) pin 3 s/b the same reading as pin 2 reading 4.92V
d) and pin 4 s/b < 1v. reading 0V

With JP1(3) open:
e) pin 1 of the 40106 s/b greater than 4.5V reading 4.92V
f) pin 2 s/b<1V reading 0V
g) pin 3 should read the same as pin 2 reading 0V
h) pin 3 s/b greater than 3.5V. reading 4.97V

Moreover, on the motor connector I read 2.37+V when it is not moving.
Shouldn't it be 0V ?


Pigi

[pminmo]

Pigi,
My mistake (again, oh well) To measure the voltage correctly on pin 17 of the L297, there needs to be a jumper on JP2. Then pin 17 should go between less than 1V and greater than 3.5 volts when you open and gnd JP1(3).

Don't be overly concerned measureing the motor voltage. All 4 motor connections will be a chopped DC signal. (i.e. on and off at a significantly higher frequency reading than your voltmeter will read correctly)

Phil

[pigifly]

Well, I didn't did the last test ( pin 17 of L297 ) as everithing now seems correct.
The motor goes ahead and back whenever I push on the button I put between GND and JP1(5) and I change the jumper JP2.

The L298 goes hot but I can "cure" it with a good heatsink, and evntually with some forced ventilation when I close everithing into a case.

For another error I did in my previous post, the voltage on the two output connector is 12V ( which is also the voltage I give to he board ) and goes from +12 to -12 when I pulse the button.

The noise from the motors is still there, and if you say I should not be concerned on this I won't.
It (obviously ) disappear if I disable the output ( JP1(1) to GND ).

It actually seems then that it should all be right, or there are other things to do ?

Pigi

P.S. Also the other drivers boards are so noisy ? I don't rember this noise when the motors were on the printer

[pminmo]

Well, I didn't did the last test ( pin 17 of L297 ) as everithing now seems correct.

For another error I did in my previous post, the voltage on the two output connector is 12V ( which is also the voltage I give to he board ) and goes from +12 to -12 when I pulse the button.

(I suspect that is correct if your using it in the full step mode)

The noise from the motors is still there, and if you say I should not be concerned on this I won't.
It (obviously ) disappear if I disable the output ( JP1(1) to GND ).

(see if going to the half step mode changes the noise level)

It actually seems then that it should all be right, or there are other things to do ?

(Other than run the motors for a while to see if anything crops up, not at this time, but you'll have to heat sink before you do that)

Pigi

P.S. Also the other drivers boards are so noisy ? I don't rember this noise when the motors were on the printer

Could be for several reasons, I wouldn't expect them to be real loud, but I would expect you to notice the noise. Some printers have sound deadining in them, they might also be running drivers that can do microsteps which are supposedly quieter.

Phil

[pminmo]

What's up pigi? Any new news?

Phil

[pigifly]

I'm sorry being in late, but I had to spend some time in create something to test the board.
I ended up in adapting and building this circuit ( in attachement).

This demonstrate that everithing it's all right on the L297 Board. I can move the motor back and ahead, and change the speed of the motor.
At some speed the motor loose some step, but I suppose it's a problem with my circuit, not with the L297/8 board.

If you want, I've created a board with 3 of this circuits, and routed it. This could be used as test circuit, rather than a simple "hand controller" for the boards. We could maybe upload on your site.
I have also a version "single" output that is very good for tests.

On the ENA jumper it should be attached a pushbutton Normally Closed, and on the DIR jumper it s/b attacched a normal switch. The supply comes directly from the L297 board, and the output connector is compatible with the input connector of the board.


Let me know what do you think.
Pigi

[pminmo]

Pigi,
I wound up doing something similar, only I used a different oscillator. I just wanted to touch base and make sure you were still on track. I suspect, that your lost steps have to do with the power supply motor voltage and speed. For example if you are using a 12VDC power supply on a 7 volt motor, you wont get as much speed as if the power supply was 35volts. The other thing is that steppers aren't really fast, if you look at the step torque curves, many fall off very quickly above 1,000 steps a second, which isn't that fast. And if your running a low poser supply voltage it's less. Send me your Eagle files on your circuit.

Phil

[pminmo]

Pigi,
What diodes did you use? Did the board have too much space allocated for them?

Phil

[pigifly]

I used the indicate diodes : 1N5822 and I have to say that the space on the board is correct. Not too much, not too few.

Why this question ?

P.S. I will take some photos of my board and post it there as soon as I go home.

[pminmo]

They take a lot of room, I think I have found some alternates that are smaller.

Phil

[pigifly]

I think that there is no need to reduce more the board.
The last design should be OK, otherwise there would be problems in routing the link under the diodes, if we don't reduce the size ( thus the power that could be supported )

Here the photos......

Let me know.

Pigi

[pminmo]

Pigi,
Looks great!

Phil

[pigifly]

Phil, a stupid question....
the home switch could/should be used as limiter switch or they are intended exactly to indicate home ?
and in this case, witch connector could be used as limiter switch ?

Pigi

P.S. I have three board now, and I will start to attach the motor to my mill, and I have to say a very special thank to you, and to everyone on this board that worked on this wonderful free electronic.

[pminmo]

Pigi,
It depends on the software you use. A lot of configurations use 3 switches on each axis. a + limit, a - limit, and home. The limits are on each end of the axis, and the home close to one but inset so as not to indicate home prior to indicating limit.

Phil

[pminmo]

Pigi,
Couple of things, I noticed a layout issue today. Attached is the image. The green area is the ground path to the L298, there isn't enough copper under heavy loads. I suggest you add a wire (shown in red) to the ground pin on the power connection. Also, what do you plan on driving the inputs with, PC wise. You may need to change the 40106 to a 74HC14N which has lower thresholds and would be more compatable with a lot of PC's. The last is have you downloaded the all the associated files for this board? i.e. copper, schematic, layout and eagle files? The reason is I've done a little tweaking and updating and want to upload to the website.

Phil

[pigifly]

Phil,
first of all thanks for your advice. I will fix my boards asap.

For what concern the other files, feel free to make any change to your site, as I have worked on my own copies, and used the master generated from eagle, thus I don't need other files more then eagles one

For PC software, I'm actually workng on a driver for linuxcnc ( www.linuxcnc.org ) and I would like to use it.
The software is free but actually lacks of a driver for your ( our ) board. After I finished my work there, in linuxcnc there would be support for every BOB you have on your site.

Pigi

[pminmo]

Thanks Pigi,
Keep me posted. I believe the 4 axis interface board that is now on my site reflects linuxcnc?

Phil

[pigifly]

No Phil, the board on your site has all the pin swapped from linuxcnc ( standard ).

linuxcnc has
D0, pin 2 X direction
D1, pin 3 X clock
D2, pin 4 Y direction
D3, pin 5 Y clock
D4, pin 6 Z direction
D5, pin 7 Z clock
D6, pin 8 A direction
D7, pin 9 A clock
S3, pin 15 X/Y/Z/ lim +
S4, pin 13 X/Y/Z/ lim -
S5, pin 12 X/Y/Z/ home

while on 4 axis there is

D0, pin 2 X clock
D1, pin 3 X direction
D2, pin 4 Y clock
D3, pin 5 Y direction
D4, pin 6 Z clock
D5, pin 7 Z direction
D6, pin 8 A clock
D7, pin 9 A direction
S3, pin 15 X/Y/Z/ lim +
S4, pin 13 X/Y/Z/ lim -
S5, pin 12 X/Y/Z/ home

[pminmo]

L297-L298 Board files updated on the website.
http://webpages.charter.net/pminmo/cncelectronics.htm
Phil