Misc surplus controllers, need help

[Hobbiest]

All right guys. I have access to a bunch of controllers from some biomed injection syringes. They have two stepper circuits, L298 or 97, can't remember which, and they are in the garage right now so I can't check. My digital camera is down...dead actually, so I can't post photos. I was wondering if anybody who seriously knows about this stuff (I am a nuts and bolts guy, not watts and volts), would like a trade. I will ship you two of these boards (4 axis total) in exchange for any info you can give me about how to use them. I would also like an interface board (perf style or whatever) sent to me, and a basic drawing of the schematic for said board if possible, So that I can use them. I am not opposed to figureing out how, and what to get at Radio Chack to build it either, if somebody could help. In other words, this poor boy, may be able to finally get his machine up and running, with these free controllers, if anybody will trade me (provided that it is even possible). I have a machine in the garage that is built out of aluminum scrap castings and extrusions, using much modified drawer slides, and 1/2-10 acme. Very stout for what it is. But I have no way of getting it going without your help (at least not until we are done remodeling our house and sell it. O'Course, then I will be extremely busy building our new house almost completely by myself as those funds will be severely limited and all for the purpose of having a mortgage free house so that I can have more time and money for all of this other insanity!). In the immortal words of Pink Floyd, "is there anybody out there?". Whew!!!! I either need to go to bed or get a cup of tea, a smoke and admire my handywork on our house (just got the tax refund and am trying to finish the whole house for $2000! Wish me luck!).

Cheers!
Jens

PS...sorry for the rowdy ramble...don't know what got into me!

[vladdy]

ok...I could use a challenge.. sounds like a pretty fair deal...
give me a private email if you're interested...
If you can get a photo or other possible model numbers off the controllers themselves, _might_ be able to figure out enough from that to see if they are useable for you [and me], and what hookup requirements would be..

let me know..

[vladdy]

Got the boards yesterday afternoon, and as I mentioned in the email to you..
They are serial ..RS232 /RS485 or possibly CANBUS ..not parallel..
They drive two motors, with optional / possibly required encoders on S1,S2, and S3..
Power input is probably 24v or so [caps are 35v], and input is max 2 amp [on baord 2a fuse]..
The rotary switch is 'likely' address selection for multiple units..

I will pull the eprom [with the eprom onbard it 'probably' will support microstepping], and read it later on..
The op codes in the eprom will give a much better idea of what it needs for imputs and instructions..

The conversion to parallel port operation is probably not feasible, as the are no onboard 'step to phase' driver IC's, unless you want to build that as a front end and just use the 298 drivers..in which case it may be easier to use one of the DIY 298 based controller designs [here on this site and elsewhere], and make a new pcb and using these for some of the major parts, primarily the 298's as most other components are surface mount SMD style..

I should have an hour free later tonight so I can give you some pinouts for testing, as well as ?possibly? jumper settings, etc..

later

[vladdy]

Ok..
to start out with, the input port can be serial at either 9,600 or 38,400, no other speeds supported. Settings are 8 daty,no parity,1 stop bit..and half [not full] duplex..

If you use RS232 [standard serial] it's ok, if you use RS485 serial protocol, you must set the termination on THE LAST controller board with JP2 [in the middle], by both jumpers on , if you are only using ONE controller, this is by default the last controller, so these need to be on. You can leave them on even if you use RS232 as they will be ignored.

the baud rate is selected on jumper block JP1 [the large one] on pin set 4
OFF=9,600 ON=38,400

it will support microstepping, by using the internal eprom code, 1/8 mode only..and this is enabled by JP4 pin set 2 = installed, Eprom ?should be? ON JP1 pin set 3

For initial testing, I would set eprom=off [JP1 pin set 3 not installed], and ,
JP4 pin set 2 not installed, I would also set current limiting on JP1 pin set 1....

It looks like the eprom code will support a rudimetary current limiting mode, not by reducing current, but by sensing a current overload to the stepper motors. This is automatic, and can be bypassed by placing a jumper on JP1 pin set 1 = Disabled

Command set contained on the eprom listing as follows...
A xx move absolute step count report busy
P xx move relative motor1 report busy
D xx move relative motor2 report busy
Z initialises motor1
Y initialises motor2
Z0 or Y0 initialise full motor power
Z1 or Y1 initialize half power
Z [or Y] 13 to 40 intiliaises with speed 13 to 40 used also with;
S set speed 13 to 40 [ie: S13] eprom default value=11
Direction is obtained with the I and O commands, ie:
I sets direction clockwise [I assume]
O sets direction reversed
v [lower case] is start velocity , eprom default is 901, so I assume steps per second?
V [upper case] is maximum velocity, eprom default is 1400
K is backlash adjustment, in steps, eprom default is 24

you have to generate a command string, and send it to the controller, along with R to execute the string,

X indicates it will repeat last comand string, Also;
H halts command string; or H3 will halt in 3 steps, etc..
T terminates the current command string at the point where the command is recieved, if previous command are NOT sent indicating a BUSY return to the software, otherwise [I assume] it would not terminate [or halt] until current command was completed..

Lower case commands, ie: a xx ,same as upper except do not report busy to host software.

the command & indicates that it will query and return current firmware version..

Ouput [back to software] codes;
0 no error
1 initialized [or possibly initializing?]
2 invalid command
4 eprom failure [or checksum error?]
7 device not initialized properly
9 motor 1 current overload
10 motor 2 current overload

JP1 3 Installed [Eprom Active] and Device switch set to 'F' internal codes indicates SELF TEST MODE

Connectors;
DB15 is power / gnd / signal in&out

PC DB9 PC DB25 FUNCTION CONTROLLER CARDFUNCTION
N/A N/A POWER 1 POWER
5 7 GROUND 9 and 10 GROUND
2 3 TxDATA 2 RxDATA
3 2 RxDATA 3 TxDATA

see attached image for reference....

To drive these controllers you will need a CNC program that supports serial cards, as well as device addressing, I use parallel [simpler] myself for hobby use, not sure if this is the answer you were looking for, but that's about all I can get from this in one hour..

enjoy..

[vladdy]

I spent a few minutes tonight to see if there were any 'relatively' cheap parallel to serial converters available out there, not a great deal of success..
Most seem to start at around $100 or so, plus shipping, etc,, probably not worth it to try this route with these driver boards..

I'm going to try and see if I can find any demo / shareware / free gcode to serial stepper driver programs out there... none readily come to mind, but never really thought much about them before..

[Hobbiest]

Thanks a lot for all the info. It still is all gibberish to me, but from what I do understand, I might as well just save up for the hobbycnc board, or the xylotex, or like you said, build my own from some of the free designs. Are the 298's worth desoldering? What are some books, websites (books prefered, like to sit on the porch with a cigarette and tea), or other ways to learn about electronics? I am very good with circuits, but don't know didly about elec. Thanks a lot for the input.

[vladdy]

If you have access to a 'larger' amount, say six or more, it is definitely worthwhile to pull a couple of the 298's out, they're not real expensive, but are a substantial portion of a homemade parallel port driver card..as well as the SMD diodes [eight on each channel between 298 and stepper connectors]. Other good parts are the heat sinks [well designed], and the photo interruptors can be used for limit switches if you choose to, S1/S2/S3..
I'm now looking to see if there is some way to drive [at least one channel] directly from the serial port, by using the address mode three can be use basically just the way they are with little [ or no ] modifications..

if you want to, take a look at some of the applications notes from the 298 manufacturer's web sites.. these give a good idea of the basic 'guts' of how the 298 drives a stepper, most hobby designs use a 297 or similar to drive the 298 and provides phase controls..

examples..
home.att.net/~wzmicro/l298.html
http://www.micromint.com/app_notes/p...p/wrkshop6.htm
www.st.com/stonline/books/ascii/docs/1679.htm

lots more out there, as well as on this site..
If you are going to 'roll your own' my personal recommendation is go for a relatively 'simple' design, probably using current limiting resistors.. that way you have a better chance of getting it to work 'quickly', before you run out of ambition [or patience]...

remember.. this is 'supposed' to be a hobby ...

[Hobbiest]

that way you have a better chance of getting it to work 'quickly', before you run out of ambition [or patience]... remember.. this is 'supposed' to be a hobby

A year and a half ago I built my first machine...total POS, but it ran. Wasn't mine, partnerships disolved, machine was never used. Then I built two, (well actually one full, and two "half dones") just to learn more about the mechanicals. Couple that with always being broke, having wife and three kids, selling my Stepperworld controller while I didn't have a machine to run the stuff on, and trying to figure out the least expensive, best hardware store guides, and about 1,000,000 other things, and it is amazing to me that I haven't lost patience or ambition yet. I spent three years once building a car from scratch, so I think this should be no sweat (better get it done this year then-hehe). I think I will just hold on until wee sell our house, and buy a driver, and sometime in the future I'll try to build one.