Troubleshooting the Simple BreakOutBoard and L297 driver

[pigifly]

Hi.
I've just finished building the simple BOB.
I will leave my experience (and all the help I will receive ) on this thread for everyone need to have help on this couple of components.

I think the job should be divided in ( at least ) a couple of step:
The very first one is to test that no ( unwanted ) current flows to the PC port.

The other one is to test that the board works correctly with the software.

Any other hints ?
How should I start with those steps ?


Pigi

[pminmo]

Pigi,
First put power on the board without it hooked up to the pc or driver boards. LED1 should illuminte. Hopefully you saw the errata in the document and installed a jumper inplace of LED2 ? Assuming LED1 illuminates, LED7, LED9, LED10, and LED11 should not. If those verify, placing a jumper accross Xhome should illuminate LED9, placing a jumper accross Yhome should illuminate LED10, placing a jumper accross Zhome should illuminate LED11.
If all is well at that point jumper pad1 or JP4 pin2 to 5VDC pad, when you do that LEd7 should illuminate.

Phil

[pigifly]

Everithing ok on this step.
Removed ( should read better the docs ) the led2 and tried every think you said.
Every led lights up as from docs.
There are few pins on DB25 that have little tension on it ( no more than 1,20 V ) but that should be ok.

Now what ? ( while waiting on L297/8 delivery )


Pigi

[pminmo]

Pigi,
Jumper a wire from Pad 1 to J. Monitoring LED7, you should be able to short alternately the RST(X8) and Estop (X7). This is the Emergency Stop Latch. The LED should hold the On or Off state as you alternately jumper between X7 and X8. If your ok there your ready to hook it up to your computer.

Consider downlaoding a parallel port monitor such as lpt.exe here:
http://neil.fraser.name/software/lpt/


Phil

[pigifly]

Also this part went well.
Ready to hook the PC, then ?
What next ?

Pigi


P.S. A little question:
the sw I've decided to use ( linuxcnc ) seems not to have the X-Y-Z enable signal on the printer port. Am I right thinking I can jumper the enable to +5V ( to keep the level high ) or it's better I use another software ?
Obviosly I will cut the lines toward the DB25 to don't let current flow to PC port.

[pminmo]

Hook up the PC and using lpt or similar monitor, you should be able to toggle the state of the home switches, estop and monitor them on the pc. With jumper JP4 IN , you should be able to set PIN 1 and control LED7.
The enable, no biggy. If you look at the BOB, R10, R8, and R9 are symbolized there for that exact purpose. Where those three components install, there is a small jumper land effectively shorting those components out. (I just noticed, that needs to documented, as I never intended those to be installed, was just an easy way in eagle to provide the physical hooks). One side goes to the db25, the other to each respective pin for enable for each axis. Slit that jumper for each of r8, r9, and r10 and you have disconnected the enable line form the bd25. You can use the pad that connects the enable line to either wire it high or low depending on which state you want or you can wire them to either pad j or l so that estop controls enable. I'm at a disadvantage here I know nothing of linuxcnc. I would suggest setuing up the software.

Phil

p.s. If you or anybody out there has a word processor compatable with Microsoft Word, I'd upload the document so the info here could be added.

[pminmo]

pigifly,
how's it going?

Phil

[pigifly]

Phil, I'm sorry but I haven't received the L297/298 IC yet.

They should be here tomorrow. For the moment I've finished the board anr installed all the other components.
We should wiat until tomorrow evening to accomplish the tests.

If you already have some tests for me I will execute it tomorrow, after installed the chip.

Pigi

[pminmo]

did you hook the BOB to the computer?
Phil

[pigifly]

Yes. I did hook the BOB to PC and everything seems ok.

The L297/8 have been installed to board, so I'm ready to test.
What to the JP3 is for ?

Pigi

[pminmo]

JP3 is for full step or half step. Jumper in is full step. I'd start testing the driver board without anything but power applied, and a jumper from JP1-1 to gnd (this diables the L298 driver outputs). When you turn power on LED1 should illuminate. Measure for 5vdc from JP4 pin 1 to pad IGND. S/b 5 +/-.2
Adjust trim pot R16 for the current limit reference voltage. With .5 ohm sense resistors for R1 and R2, the current limit voltage would be figured as Vref/.05= Imax.
So for a 2A motor Vref = 1V, for a 1A motor .5V....
What if any do you have in test equipment? Voltmeter?

Phil

[pigifly]

My setup include digital and analogic voltmeter, and I can use also an oscilloscope. I don't know very well how to use it, but I can have one ( dual trace ) if needed.

Let me see if I have understood well:
JP1(1) to gnd.
JP4 open.
test 5v from JP4 (1) to pad IGND ( it should be the same to test to one of the GND pin of JP1 isn't it ? )

How can I test the vref ?
I should test between ping 15 of L297 and gnd ?

Pigi