>Folks >>I'll upload the code tonight to Avsim's file library, plus a >small demo program in VB so you can see how to use the >classes. Stay tuned, and please provide feedback. >>Dave Really looking forward for it!Are going to provide connection diagrams?This way i could test the max right away i think (hoping the vb thing is not too much complex)Best regardsClaudio

Is it possible for someone to create a "7-Segment Display System for Dummies" paper describing all the wiring/components required, as well as how everything is connected? I'm sure it would be a great help to those just starting out.Best regards,Pesach(KJFK)

Well, I've got some hideous back-of-envelope drawings I could tart up and upload. Maybe I'll do that, shouldnt be too difficult to do....Give me 'til tomorrow and I'll get some nice piccies drawn up to go with the software.Dave

OK,Just uploaded to the file library a file called "FSDigit.zip"Archive includes a basic circuit diagram, textual description of how to build the circuit (very easy even for beginners, one IC and one resistor, doesnt come much simpler than that!). Also included is the .dll that drives the displays.In all, building the circuit should take about 30 minutes. It took me about 25 or so, but then my two-year old got loose with the soldering iron!Anyway, take a look. Comments and feedback welcome. More code to come that does more useful things, but anyone who can code even a little will be able to use the supplied classes, they do a pretty good job of abstracting the complexities of serial emulation over a parallel port! Coupled with FSUIPC you have basically everything you need to build your displays for a cockpit. And cheap, cheap, cheap!!RegardsDave T

Thanks so much Dave!Will go and checkout the file now.Best regards,Pesach(KJFK)

Dave,The MAX7219 has arrived... I wonder if you re still going to send me code through e mail, in case you didn't get my e mail address it's [email protected]. Or can I find it in file library? Let me know.

ArthurDo a search in the file library for fsdigit.zip - It had everything you need to test your circuit and get going!RegardsDave T

Hi Dave, Would it be possible for you to send the word doc to my email. Everytime i try to open it from the zipped file I get this fault: WORDPAD caused an invalid page fault in module MSWRD832.CNV at 0167:0140f6d5, and the page shuts [email protected]

The search at digikey found the following parts (each are priced differently):MAX7219CWGMAX7219CNGMAX7219EWGWhich one do I purchase?Best regards,Pesach(KJFK)

HiYou want the 24pin DIP package, I think its the CNG one (you should be able to check that the package is 24pin DIP online)RegardsDave T

Hi Dave,Ok. So I bought all the parts and installed the software and am experimenting with the radio shack IC breadboard. I have three single 7-seg displays which I'm trying to run. I have a few problems (bear in mind that I have NO IDEA about electronics): 1) Where can I get a +5V supply to power this circuit? Would a 9-Volt battery suffice?2) I had used a regular 9-volt and reduced the voltage to around 5V using a series of diodes but I only get the letter "C" on the first and third 7-seg display. And it doesn't change when I click on the "write" button. 3) Also, the first 7-seg is bright and feels really hot, whereas the third one is dim and not hot. Is this a voltage or current issue?4) I am trying to run multipile single 7-seg displays and you can find the spec sheet at: http://rocky.digikey.com/WebLib/Lite-on/We...a/LTS-4301B.pdf Is the circuit adequate for these 7-seg display?5) Am I doing something wrong? I've got MANY wires going from the 7-seg displays to the MAX IC. How simple is this circuit supposed to be for beginners?6) Where can I find cheap boards that can hold multiple single 7-seg displays neatly?Computer specs: Trashy Win98se comp with too little ram to even mention. Pentium 133 processor.Thanks so much for your help!Best regards,Pesach(KJFK)

Hi PesachFor a single 7-seg, you should have 9 wires from the breadboard (maybe 10 in your case). Connect pins 8 and 3 on your LED to digit 0 on the MAX. Then connect each segment (seg A to seg A etc) on the MAX to the corresponding segment on the LED. Make sure and use digit 0 on the MAX to connect to pins 8 and 3 on your LED.Then, ensure that you have 4 wires from the parallel port. Data, Clock, CS and gnd. Connect ground on the par-port to the ground pins on the MAX.I'd be careful with the voltage. I dont know how tolerant the MAX is, I bought a 5v DC supply from Radio Shack for about $10.00The only other component is a resistor (dont remember the pins), just make sure its there otherwise you risk burning out the LED and the MAX.And then play with the software. Its a pretty straight forward circuit so you shouldnt have problems, I built the prototype on a breadboard and it was fine.Since the LED shows some activity, that indicates that its working (to a degree), but the heat angle worries me a bit - I'm driving a lot of LEDS and the device stays cool to the touch. You might want to check your supply.RegardsDave

One other point - I'm not sure how you are using diodes to reduce voltage, you'd be better off buying a cheap voltage regulator...

Hi Dave,Thanks so much for replying so quickly! I actually only have three wires from the parallel port -- I don't have the ground wire. (as a side-not: I think you may have left that parallel port ground connection out of your docs). I have the 47K resistor connected already.Will all 7-seg leds be driven with the same power from the MAX chip? Or is that only an issue when I put LEDs in series?I'm putting diodes in parallel to a 9V battery and I get approx 5V on the output. Maybe I should just get that 5V supply from radio shack. If you add 7-segs to the max number allowable, will it run on that one 5V supply?Are there ready-made boards that hold 7-seg displays? The wiring is getting ready messy.Thanks for your help!Best regards,Pesach(KJFK)

One more thing: Do you have the part number for the 5V power supply from Radio Shack?Best regards,Pesach(KJFK)