Jump to content

Sign in to follow this  
Guest

Any Circuit diagram for Seven Segment display that can

Recommended Posts

Guest

Hi Guys, I metioned on other forum few months ago about seven segment digit display. I am looking for anyone who know or has experience going through build up circuit and have seven segment digit display to work with EPIC instead of purchasing another board which I already have. You see, My cockpit needs about 42 display to operate like real life situation, and the board manufactured by EPIC can only get it operate up to 32, Like wise I would need 10 more display to operate. And I did not want to purchase another board. instead of build up up to 10 displays. So any idea about circuit diagram, or refer to your experience if you have? Let me know.

Share this post


Link to post
Share on other sites
Guest MikePowell

Hi, Arthur,Have you seen what Dirk Anderseck is doing with PIC micro controllers over at www.fsbus.de ?Mikewww.mikesflightdeck.comInfo for simpit builders

Share this post


Link to post
Share on other sites
Guest

Hi ArthurIts also possible to use MAX7219 direct from the parallel port. With 8 data pins available, you get 64 segments per device, 8 devices per pin, so lets see, thats 8 * 8 * 64 = 4096 idividual leds, or 64 7 segs plus some extra.I'm doing this right now, works very well, and no EPIC needed. Cheap too, about $7 for the MAX7219 plus the cost of 7-segs.Dave

Share this post


Link to post
Share on other sites
Guest MikePowell

Dave,What software are you using to interface to FS, and to talk with the parallel port?Mikewww.mikesflightdeck.comInfo for simpit builders

Share this post


Link to post
Share on other sites
Guest

Mike, Thank you for this wonderful webpage... I took look at it and it seem to be the perfect webpage in which, that way I could collect all information about build up circuits. Thanks again.Dave, About MAX, sound good. But would I need PIC, or any such microcontroller to operate with seven segment displays? would it work with peter dowson's vxd?? for my cockpit, I would want it to display same number once FS2002 indicate such as COMM Frequency, say will that chip work?

Share this post


Link to post
Share on other sites
Guest

MikeI'm using some classes I wrote to abstract the parallel port, basically you represent a pin on the port as a logical serial device, and just give it a bunch of "digits" that know how to render themselves over the serial link - if you want the class binaries I'll email you them to play with. For talking to FS, I'm using FSUIPC, again i have a class that abstracts an offset. Then just some real basic glue code that periodically reads from FS and updates the display.In the future though, I will link the classes for writing the port direct to the rotary encoders (faster update cycles), and then periodically write to FS the value that the display controller has. I have this functioning now, but the code is ugly!!! The end state is that everything will be modular and linked to a work-flow framework (which I have built already). You can then swap bits in and out. (Its written in VB6)Very cheap, very fast, and works like a charm!!RegardsDave

Share this post


Link to post
Share on other sites
Guest

Hi Arthur,you dont need a PIC - basically the software makes a pin on the parallel port behave like a serial device that is compatible with the MAX serial input port. The classes that talk to the MAX dont talk to FS, but I have other classes that do exactly that. They extract the value from the offset, apply a "adjuster" (so that we can turn the FS values into, say, degrees) and then pass the data to the classes that talk to the MAX. For driving the MAX, you need a parallel port device driver, I'm using tvichw32.zip (do a google for it). The classes then make calls to this device driver to send the serial data. Works very well.Dave

Share this post


Link to post
Share on other sites
Guest MikePowell

Thanks, Dave.Sounds like a nice approach; cheap and fast. I'm working with PIC's and serial interfaces right now, but it's nice to know there are still other options. (Haven't got the patience currently to invest the time in learning USB.)Mikewww.mikesflightdeck.com

Share this post


Link to post
Share on other sites
Guest

Hi Dave, Really, I could get those digit working with parellel port using Max chips? Why wasn't I told?!?! That would have saved me some money instead have to spend on EPIC. Now I am duly noted and would get to use it for my next project when I am ready to start working on interfaced circuit with MAX's IC chips (More likely it will be Dornier 328, DASH 8, SABB 240 and such other propeller commute aircraft) Any wau would a such command program get those digit to function in my desire method be a free downloadable? where can I find those through webpage? How will I start learning about those program. Actually I am somewhat proficent into connecting up digits with IC or such other components, the problem is I m some what "stupid" into programming except for EPIC. Share some details regarding to your experience, or your advices.P.S. Where can I find webpage for MAX chips, I think I am ready to order one of those.

Share this post


Link to post
Share on other sites
Guest

Arthur,Web page for MAX - take a look at www.digi-key.com and do a search for MAX7219, you'll find a data sheet for the IC there.Once I have the software working satisfactorily, I'll upload the binaries for sure. I have the classes working fine, if you want a beta set drop me an email and I'll send them by return. You'll need to know VB, or some language capable of calling into a COM component.Dave

Share this post


Link to post
Share on other sites
Guest

Hi Dave, Thank you for the reference for MAX Chips, it was truly appreciated by me.First of all, I assure it'd be much easy for me to attach wire circuity of MAX7219. This is the least fear I ever experienced. I have all knowledge with digital chips and I am somewhat proficent into electronics.But the least knowledge I have is doing the with Visual Basic. This is my most fear of doing it, It sure gives me few headaches if I am unable to know how to use it. Well, What I am saying is... I have no problem typing in those commands as I did to EPIC, I have no Problem understanding BCD system. The only problem I have is I am not aware how to start creating program, I don't have that kind of knowledge in the values or parameters based on flight simulator 2002's requirements. So, if you be so kind to try to help me out by bring up advices, or any kind of recommend for me to be able start learning how to use Visual Basic, I would be so much obliaged to start inputing those VB details in my brain. What reference would you recommend me to start off learning how to use Visual Basic at home? I would be obligated for that, I would be rolling up my sleves and have moviation for this. Anyway, You can send the Beta set to me at Projectb767@aol.com. Once again, Thank you for all of those wonderful, information you shared with me...

Share this post


Link to post
Share on other sites
Guest

Thank you for the reference for MAX Chips, it was truly appreciated by me.First of all, I assure it'd be much easy for me to attach wire circuity of MAX7219. This is the least fear I ever experienced. I have all knowledge with digital chips and I am somewhat proficent into electronics.But the least knowledge I have is doing the with Visual Basic. This is my most fear of doing it, It sure gives me few headaches if I am unable to know how to use it. Well, What I am saying is... I have no problem typing in those commands as I did to EPIC, I have no Problem understanding BCD system. The only problem I have is I am not aware how to start creating program, I don't have that kind of knowledge in the values or parameters based on flight simulator 2002's requirements. So, if you be so kind to try to help me out by bring up advices, or any kind of recommend for me to be able start learning how to use Visual Basic, I would be so much obliaged to start inputing those VB details in my brain. What reference would you recommend me to start off learning how to use Visual Basic at home? I would be obligated for that, I would be rolling up my sleves and have moviation for this. Anyway, You can send the Beta set to me at Projectb767@aol.com. Once again, Thank you for all of those wonderful, information you shared with me...

Share this post


Link to post
Share on other sites
Guest

Hi Dave, I am still wondering if you would be able to attach the beta set to my e mail?

Share this post


Link to post
Share on other sites
Guest

ArthurForgive me, I'm travelling for business and dont have access to the code. Soon as I get back (late Wednesday), I'll email a copy plus a small test program that you can use.Dave

Share this post


Link to post
Share on other sites
Guest

Hi Dave, That's okay.. Take your time.. enjoy your business trip. On other issue, I figured out that IC7446/7447/7448 would work same way as Max7219, wouldn't they? Would that have 8 data bits similar to Max7219? I did few research on both chips through internet. The only thing I don't understand the function of MAX7219. I am assuming it's for digit display to make a communication to parallel port, which can be determine by the desired value through programming system, and 7446/7447/7448 wouldn't have that, is that correct? Lemme know : D

Share this post


Link to post
Share on other sites
Guest

Arthur,No, I dont think they are the same thing at all. The MAX has a serial interface and can drive 64 individual LEDs, and while I dont know what a 7448 is, if its a 74LS series IC of some sort, then I'm pretty sure they are not the same thing.Dave

Share this post


Link to post
Share on other sites
Guest

Hi Dave, Okay... I am duly noted, They are not same... Apparently, all of the information I need are stacked up in my mind, except for one thing...Do you know if I could find any circuit diagram of Max7219 along with Seven Segment digit display? I just want to take a look at it and prepare everything because I have already order MAX7219 from digitkey.

Share this post


Link to post
Share on other sites
Guest MikePowell

Arthur,You can find a lot of information about the MAX7219 on the Maxim/Dallas web site www.maxim-ic.com/quick_view2.cfm?qv_pk=1339 The 7447 and similar chips are very basic seven segment decoder/drivers. They take a 4 bit BCD code as input and provide the drive current for the individual LED segments of a single 7-segment display. The MAX7219 or ICM7219 and their varients are significantly more complex and capable. You might think of them as incorporating the 7447 circuitry along with memory to hold the digits they are to display, an interface better suited to micro processors and the scan circuitry to allow driving 8 7-segment displays.Mikewww.mikesflightdeck.comInfo for simpit builders

Share this post


Link to post
Share on other sites

...that actually sounds like the ol' 7447 - 7490 Up/Dn Counters with Latch.Living a few blocks away from the local Radio Shack as a child did have it's advantages, but was a constant drain on my allowance!

Share this post


Link to post
Share on other sites
Guest MikePowell

That's it. This functionality was developed back in the days of nMOS chips by Intersil (probably by others as well) as a replacement for the TTL approach. It's been improved as silicon processes have developed, but the functionality is pretty much the same. Mikewww.mikesflightdeck.com

Share this post


Link to post
Share on other sites
Guest

Only thing I hear is, 7447 has a constant changing on the BCD based on everytime I toggle the switches. but, would not make a compatible with EPIC-- meaning, for instance if running FSXX it will not send any such kind of data information regarding to COMM, NAV or such other kind of freqs along with IC7447 (would not appear on any seg). Unless, I would need to add more chips that would have this kind of function (storing information/memory) . So, MAX7219 has everything I need, and it would be the best answer...

Share this post


Link to post
Share on other sites
Guest MikePowell

Arthur,You are correct. A 74LS47 would not by itself do what you need. The MAX7219 has significantly more functionality. You could build that same capability by using a number of 74LS-series chips, or by using a microcontroller like a PIC16F628 with a few support chips, but it is likely more simple simply to use the 7219.Mikewww.mikesflightdeck.com

Share this post


Link to post
Share on other sites
Guest

Dave you made me drop from the bed!I had the max 7219 sitting on my desk for too long...I never had the courage to start assembling some code for a pic...Now you tell me you can attach one or more to that stupid thing called parallel port?I think i'll make you a monument!Could you drop that beta thingie to me too?I'm not much in oop and vb, i only now ansi c...But i could anyway use a look if you don't mind.Since max7221 have Cable/Select pins, have you thought about using many of them on the same data line?

Share this post


Link to post
Share on other sites
Guest

Arthur,whats your email address? And yes, I have them cascaded on single pin, max of 8 per pin on the parallel port. So you can have 64 hanging off a single parallel port......Dave

Share this post


Link to post
Share on other sites
Guest

I would be interested too. ThanksMy e-mail: roger.wielgus@noos.fr

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...