max6952 display driver

[deneve]

I want to design and build an LED dot matrix display board using the max6952 controlled from a pc. Has anyone played around with these - the data sheets seem complicated for the noobie. I could really do with some sample circuits and leads on how to do software control from PC ports.

many thanks

 

[philba]

Have you looked on the maxim site? probably not, from the sounds of it. there is a datasheet and 7 app notes that apply.

https://www.electro-tech-online.com/custompdfs/2007/03/MAX6952.pdf

**broken link removed** - MAX6952

**broken link removed** - MAX6952

**broken link removed** - MAX6952

**broken link removed** - MAX6952

**broken link removed** - MAX6952

**broken link removed** - MAX6952

**broken link removed** - MAX6952

 

[Papabravo]

You're going to have a very hard time with this project since PC's don't have SPI interfaces. Most of them don't have serial ports either. Bit banging SPI using the parallel port. Well Mr. Softie will do just about everything in his power to frustrate that effort.

My suggestion:
Get a microcontroller development board with an SPI capable processor and tack your MAX6952 onto that. You'll loose a great deal less hair and sleep that way.

 

[deneve]

Actually yes I have browsed some of these data sheets. Am I right in thinking that the max chip is all that is needed apart from dot matrix blocks to daisy chain any size board within reason. Also the data sheets don't appear to be clear about how you can send ascii data to the boards from an "own made program - say done in C. Maybe all this info is there but I have'nt really swallowed it up. Are my intuitions about whether this can be done like this reasonable though?

Many thanks for any advice - sorry if I am seemingly a bit dim but I haven't gone down to chip level for 20 years now and it's all changed a bit since I was there.

Nick

 

[deneve]

Thank you papabravo.
So let me see if I have you right.
First use a microcontroller to drive the max chip - probably one per chip?

then will I be able to pipe real time data to the arrangement say via USB or serial Com port to be displayed on the dot matrix and updated as by the software. The application is a message board for temperature and humidity plus calculated response variables requiring periodic software recalculation and update.

 

[Papabravo]

The MAX6952 will drive only four(4) monocolor LED characters. You may have several MAX6952 chips on a single SPI bus connected to a single microcontroller.

You're still going to have a substantial problem getting RS232 data or USB data down to the microcontroller from a PC. That process is getting so challenging that as a beginner your bitting off a large and expensive process. There is no longer a cheap and easy way of using a PC as a development tool. Maybe if it runs linux, but I'm no expert.

In short most PC's are sold without parallel ports or serial ports. They have one or more USB ports and the USB to serial converters have a mixed performance record in my experience. This connection is where you will spend the bulk of your time and effort.

Rotsa Ruck and vaya con dios amigo.

 

[deneve]

Thanks Papabravo

OK so what about using the Picaxe microcontroller system? It doesn't use an external programmer board just a single PC to USB to Micro connection. Picaxe is at



Can't I just use one of these to program the microcontroller and a velleman Input/Output board which connects to the USB to port data out to the display system?

Velleman v110 or kit form K8055 is at
**broken link removed**


Many thanks

 

[philba]

actually, the second link I listed is for an app note that shows how to drive the chip from a PC. VB (ugh,...) source code and all. It only takes a little looking... Yo may have to buy a serial card.

I suggest you read all of those ap notes before asking any more questions here.

 

[philba]

Thinking about it a bit more, if you are not faint-of-heart, look into the 18F4550 PIC. It's got built in USB and isn't too hard to drive from a PC. Use the PIC to also drive as many of the MAX6952s as you want. It will take a little learning curve but the information is readily available.

 

[deneve]

Thank you Philba

When I first looked at the max data sheets you gave me I wasn't sure whether the exe vb program was a test bed to play around with the systems because it did not seem to give clear details how to "talk" to the max drivers from the designers (my) software via .dll's. That's probably because I can't see wood for trees but I'm still not so sure!

I'm sorry if I seem a bit dim, but it's twenty years since I worked at chip level as a control engineer (been in maths and computer modeling for a long while) and I'm out of touch - things have changed such a lot - but I am keen to get back into the field. I don't always know what I'm reading about though - did'nt even know what an spi was until three days ago! I would like to feel that I can post messages even if they do seem a bit simple or I goof up.I don't want to waste anyone's time but I hope you will still consider me worthy of replying to in future.

Kind regards

Nick