Hi Steve,
My 7805 failed one of BC337 to buzzer was blown away.. I just want to know whether the PIC damaged or not? Any idea?
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Hi Steve,
My 7805 failed one of BC337 to buzzer was blown away.. I just want to know whether the PIC damaged or not? Any idea?
Sorry Khalid, I've no idea. (Although the 337 exploding doesn't sound good...) (You may also want to check the LCD.)
A lot depends on how the 7805 failed. I've never known one fail short circuit they've always failed open and so no damage. They have thermal shutdown circuitry to protect them.
Is the input to it fairly high? Maximum is 35v although this would drop 30v across the device which if we assume about 100mA is still 3W dissipation - which is a lot without a good heatsink.
If you're using a high input voltage I'd suggest either another device before the 7805 to drop the voltage (this can be offboard and bolted to a heatsink) or a separate supply (say 8-12v) to power the unit independently.
Good luck - hope it hasn't fried anything.
Hi steve, the 7805 is fed with 22V ....The LCD backlit leds are working and two/three strange vertical lines are also displayed on LCD...
I am afraid i have fried the PIC, any means to check the PIC?
I ahve an expensive PIC programmer on hand (QL-2006):
QL2006 USB & RS232 PIC Programmer for Microchip MCU
i want to program a new PIC452 with it..what initial settings i should use?The PIC is not bootloaded..need help please.
Should be fine on 22v. That's about what I run mine on, I do have a reasonable heatsink though. When it's working again check how hot it gets, as a rule of thumb if something gets too hot to hold for a short amount of time - then I stick an heatsink on it :0)
If you load the HEX file into your programmer software you shouldn't need to set up anything - it should just work. All the settings are contained within the hex file itself.
If the PIC has been fried then I'm afraid imo the LCD will have died too...
Thanks Steve:)...I have to built the complete unit again...I think someone here posted the wide-traces PCB files...
Have just to search this thread or if someone help me point out workable PCB sketch with wide and clear traces so that etching possible without any loose or connected traces..PS:
I found the LCD backlight LED's are working...i hope the LCD not damage..:)
Hi Khalid,Quote:
Originally Posted by Khalid
On page 29 post No. 347 Lucas posted the copper and silkscreen pdf of a PCB with wider tracks. This is his corrected version. There is some pictures of the built PCB on the next 2 pages.
It looks quite good to me but I would like it with wider solder pads.
I had been looking at it myself as I melted some of the small round solder pads when I soldered the resistors on Kwackers PCB.
I hope this is what you require.
Regards,
Bravo.
Hi Bravo, Thank you for pointing out and confirming the correct workable PCB with wide-tracks and thanks to Lucas too for taking time and posting his PCB...
My Question will be, the dimensions of Steve and Lucas PCB.. as it is very important for me because i have to replace the Steve PCB with Lucas PCB on the existing box..
Almost completed the 2nd Board the same as Lucas did in page 29. Lucas or anybody else can tell me why the Backlight resistor required and what is the value of that resistor?
Regards
The value depends on the LCD you use.
Most LCD's have a led array wich needs something like 4.2V and the current depends on the type of LCD.
So you need a resistor to drop the 5V to the backlight value for the given current.
In my case it was 4.2V @ 260mA, the math results in 3 ohm.
But that 260mA also passes through the 7805, if you use 24V then the 7805 has to dissipate an additional 5W so it will need a very large heatsink.
This is why I experimented and tried a 56 ohm resistor, the backlight current is reduced and the LCD readability is good enough.
Do you have the spec's of your LCD?
Note that some LCD's have that resistor already installed and thus work on 5V.
Luc.
Hi Luc.. thanks for the detail reply and calculation. Following is the spec sheet of the LCD i am using:Quote:
Originally Posted by lucas
Welcome to Kingsun United Development Co., Ltd.
http://www.topwaydisplay.com/Pub/Man...ual-Rev0.1.pdf
Onething more to ask.. The Backlight resistor is installed on 5V output of 7805 IC?? So why to give 22V or 24VDC? your resistor seems to me of 1/2watt or 3/4watt as its too fat as compared to others resistors..
Reason for the fatter resistor: didn't have a smaller one.
The entire unit runs on 5V, thus also the backlight.
IC 7805 regulates the external supply to that 5V and must dissipate the excess power, with your display and the 22V input supply you are using it will also be around 5 Watt. So a decent heatsink on the 7805 is needed.
Your display has the resistor included so you can use a jumper wire to feed the 5V to it. If it doen't have to be real bright then you could use a low value resistor.
BTW: What did you use before? Is this still the same LCD?
If it is, then it should work as your original unit before it broke down.
Hi Steve,
This is my first time programming of PIC.. i do not know much about..I uploaded your Firmware V2.1 in QL-2006 software and here in attached pictures you will find some parameters..
Are these okay or need any changes.. Dont forget i am using your V2.1 firmware.
Thanks Steve and Lucas.. My second PCB work fine now.. I have reduced the input volts to 7805 about 9VDC...
I have developed 4x4 Keypad for big buttons.. Is their anybody who can verify or correction?
Regards
Finished untested board:
Attach is the PDF file for etching.
tested the keypad and its working perfect...
Apologies if someone was expecting a reply from me... After a brief respite I've stopped getting "new-post" alerts...
Updated manual and new HEX file
Attached to his post is an updated manual with the missing options in setup I added a while ago put in.
Also a new HEX file. This file has NO extra functionality so is of no interest to most - but it DOES (in theory) work with the 18F4520, the same HEX file should also be capable of being used on a 18F452 - although I should point out I've run out of spare 452's and so haven't tested it...
If there are any problems let me know...
(Thanks to Marty and Lee for taking the time to figure out why the code didn't work properly on the 4520.)
(Just spotted, in the manual I've missed out saying you can zero position etc in any mode by pressing the zero [0] key...)
Khalid- Your keypad looks great. What sort of overlay will you use over the keys?
HELP !!
Steve has very kindly blown a couple of chips for me and now I need a pcb. I have tried the 'Press-n-Peel' film but my c****y Brother HL2030 puts two great 'cart tracks' across the print despite trying different locations on the sheet and different sheet sizes I just don't seem to be able to avoid them and I cannot get toner to transfer despite scrubbing the pcb material with scotchbright and then handling it with vinel gloves on. Is there anyone in the UK who can help me out with a pcb or transparancy of Steve's pcb design or any other so long as it works. I am only too happy to pay any costs.
Marzetti,
I dont know how to make overlay so i just painted on the button with white permanent marker.
ARTIFECERJON:
Have you ever tried the normal printer paper and ironing?.. I use the office papers to lasaer print and then ironing the design on PCB. Its simple and no special paper.
Kahlid,
Thanks for the reply but I have tried the toner transfer method which didn't work for me. I have one last hope, I have found some transparency film, the stuff you used to produce OHP transparancies before Powerpoint ruled the presentation world, and have printed the layout on to it. I hope it's dense enough to let me use it to transfer the image on to sensitised pcb material via a uv light. I will let you know how I get on.
@khalid.
A good way to make overlays is to print them on photo paper and then run them through a laminator. You can get excellent overlays doing this.
One trick I found was to run a sheet of paper through behind the overlay ( slightly bigger) then cut the overlay to size, doing this the back of the laminate comes away with the paper and prevents the overlay being too thick and rigid. (i.e. the overlay is only laminated on one side).
@artificerjon
I've never tried transparencies with a laser so can't vouch for them.
All my PCB's are made using inkjet printed transparencies though. However I find to be reliable I need to print them twice...
What I do is run the transparency through on 'luxury photo' mode (or whatever mode will put down the most ink), when it comes out hold it up to the light and you should see its fairly dense - but not quite black (if it is job done!).
I leave it to dry and then run it through again, that usually produces a nice dense transparency.
The problem with this method is registration. I find left to it's own devices my printer doesn't load the paper consistently. To get round this I apply light pressure to one side of the transparency as the printer pulls it in. I've had good results doing this even where very fine traces are used.
[edit]
I should add - make your transparency so it needs to be ink against the pcb rather than ink away. The thickness of the transparency is enough to create fuzzy lines otherwise...
Hope this helps.
Finally, I finished my Rotary table and all is well! I machined the surface and periphery of the table itself using the indexer (in continuous mode) and milled four T-slots into it in degree mode. Very happy with it indeed!
As previously reported, the self-adhesivve cheap keypad I used had one half of the connections reversed. Since this may be an issue for others as well, I have drawn a modified version of the "Lucas" PCB which allows for both versions of keypad connections.
To confirm operation, simply wire the 4 pairs of solder pads straight through with wire links. If the keypad produces wrong numbers and commands, remove the links again and arrange them in the alternative (crossover) pattern. I suggest one pair on one side and the other on the opposite side of the PDB to make it easy to keep them separated.
Lucas: could you please incorporate that in the PDF file - I have currently no way too save as a PDF file with the correct dimensions.
Cheers,
Joe
Steve, Have sent you a PM regarding a similar project I'm working on.
Thanks Pete.
Steve,
I have completed your fantastic digital rotary table indexer. I have run all tests and all parameters work beautifully, however I have one annoying anomaly. When running in degree mode I select for example 60 degree increments and press direction, table moves 60 degrees, press forward and the table advances to 120 degrees, everything works fine until I advance to go to 240 degrees. The stepper passes the 240 degree stop and continues past 360 degrees to 1.390 degrees. If I do the same with 5 degree increments it works fine until around 220 degrees and continues on past 360 degree to 1.390 degrees.
I have changed over the chips with the same result. Has anyone else found the same anomaly? Any suggestions as to what might be causing this issue? Division mode works fine right around the 360 degrees so I'm at a loss why this occurs only in degree mode.
Edit -
I'm using the 2.11 Hex code. Power input is 12V to the board, the Gecko driver is powered separately with 36V.
Cam
Hi Cam,
Just tried it on mine - and as you can guess it works fine...
Can you tell me what you've got the worm ratio set to? (or the Set Steps Per 360 - if you're using that version).
Presumably you're using a 452 and not a 4520?
Steve.
Thanks for the reply Steve, I have a 90-1 worm with a 200 step motor set at 1/10 stepping mode so the programed stepping ratio is 450.
Cam
Hi Cam,
Basically you've exceeded the resolution of the internal maths.
It calculates a value for the number of steps per 360 of the table which in your case is 200 * 90 * 10 = 180,000.
However it's a 16 bit number so the max it can be is 65535.
The last couple of versions of the firmware require this number to be entered directly and so you can't exceed 64k.
What you need to do is change the 1/10th micro step to half step (i.e. 2 steps instead of 10). In this application there's no point in microstepping anyway.
Apologies for that, the firmware doesn't check for overflow - although I think it's mentioned in the manual....
Steve.
Steve thanks for the info, Unfortunately I can't change the stepping resolution on the Gecko G250 so I'll purchase a stepper of e-bay that I can adjust to half stepping. I'll let you know how I go.
I notice a few of the others are using the Gecko 10th stepper drives, they possibly haven't tried in degrees mode for a full 360 degree rotation.
Regards
Cam
I'm surprised it works properly in any mode tbh.
If I had time I could probably have a whizz through the code and try to figure out what's actually going on when you exceed the limits.
Latest code though won't let you since you have to enter a value for 360 deg.
i also posted a video where a 144 teeth gear was machined. I am using G203V that is also 10 microstep drive but my indexer gearing ratio is less, i donot remeber but i have posted the details few pages before...Quote:
Originally Posted by Me2
I am having no problem, i am using V2.1 firmware not the latest one.
G'Day Khalid, Yep mine works fine in division mode, I ran with 130 teeth as a dry run and it worked fine. However in degrees mode it ran up until around 220 degrees and it took off and continued running without stopping at the next point, I'd be interested to see if your does the same in degrees mode with the 1/10th stepper.
Steve, I'm probably going over old ground but could give the maths for calculating the ratio. I understand that the controller is set to 400 for a 90-1 gear ratio at 1/2 step ie 200 stepper x 2 = 400. At 1/10 stepping shouldn't the controller be set at 200 x 10 = 2000. I set it to 450 at it gives the correct rotation in degrees but I think I fluked it.
I'm a little bit lost, but that's usually me.
Cam
The version of the firmware you're using makes an assumption that the motor is half stepping (i.e. 400 steps per rev).
This is one of the reasons I changed it to allow you to enter the steps per table revolution, it also allows oddball ratios and stepper motors to be input too.
Basically the maths works like this.
With the assumption you have a 400:1 half stepping motor then you'd simply input your worm ratio directly, i.e. 90.
But since you're 1/10 stepping (i.e 5 x as great) then you'd input that value x 5.
90 x 5 = 450.
With regards it working with bigger numbers, I have a theory but without working it out in the code I can't be sure...
In simple terms though I think the overwrap isn't an issue as long as the values are small enough. (I can't test it here because the later version of the software won't allow me to input a big enough number!).
Kwackers and Me2:
I'm using the G251 (1/10th step) driver too. My worm ratio is only 30:1 though, that's why mine works fine too.
What you say makes perfect sense, Steve - I'm glad I accidentally used this small ratio worm drive!
Me2,
The same happen to me when i was using cheap chinese keypad..it was very sensitive, also i was using the PCB by the STEVE at that time..may be some problem,... After few days my whole PCB and the PIC IC found damaged, so i did the new PCB with thick routing someone posted 3 or 4 pages before..I also made my own version of keypad and now i have no problems at all..
I will check by tomorrow whether in degree mode i also get the problem like you.
Thanks for the input and help felle's, Payday next week so I'll buy one of these -
Cnc 3.5A 2 phase hybrid stepper motor driver controller | eBay
Should do the job nicely. My input power supply is 36V.
Cam
G'day Steve,
Received my half stepper driver today. Hooked it up and everything working perfectly. Very happy! I've printed off a few keypad overlays, they are the one side laminate as previously described. What have you or others done to 'glue' them down to the face of the keypad, I was looking at a non wetting adhesive like silicon so the print doesn't bleed from underneath when in contact with the adhesive. Any other alternatives?
I'll post pics when I get the whole thing into a box and setup.
Thanks again
Cam
G'day Steve,
Received my half stepper driver today. Hooked it up and everything working perfectly. Very happy! I've printed off a few keypad overlays, they are the one side laminate as previously described. What have you or others done to 'glue' them down to the face of the keypad, I was looking at a non wetting adhesive like silicon so the print doesn't bleed from underneath when in contact with the adhesive. Any other alternatives?
I'll post pics when I get the whole thing into a box and setup.
Thanks again
Cam