Got my kit...

Bamse

Howdy,

Got my kit on Friday, hooked it up and ran a few demos, everything works great...
Then I started reading the book and I still am reading it...
Great work, it explains everything just on my level, not to easy neither to hard...

I just got to finish up my 24x24 LED sign controlled by my Replica I (A 6502 based Apple I clone) so I can start learning the Propeller.

Great work Andre'...

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Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

T&E Engineer

Good luck with your Hydra. I bought one too recently but haven't been working on it due to an SX project for the moment. I see you want to build a 24x24 LED display. I have built a few of them with my largest recently being 16x16 powered by an SX52 protoboard.

Here's the link. Its about 1/2 way down.

http://forums.parallax.com/showthread.php?p=636887

AndreL

Good thanks. Make sure to run thru all the demos in the demo coder chapter 25, so you can see what crazy stuff we made it do.

Andre'

Bamse

My LED display will of course sooner or later be wired to the Hydra...
I'm actually making it easy for me, the 8x8 Led segments are pre made and I'm using nine MAX7219 to drive them...

So far, I just mounted the LED Segments...



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Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

Post Edited (Bamse) : 3/26/2007 4:44:55 AM GMT

Jasper_M

When that's wired to the Hydra, you could program a Tamagotchi or something for it : P ... also, I saw once a racing game made for a small LED display...

T&E Engineer

Bamse,

I love the larger display. Have you tested the LED's to make sure they are bright enough? My 16x16 display will have to use premade displays like this because they are simply not bright enough (e.g. MCD) - although they are ok for testing. What made you choose 24x24 and not another size? Currious thats all about the design. I have also Googled and seen 16x16 single·piece·LED displays (that I may use). I·currently·am using an SX52 for all of it's I/O. However, the MAX7219 is a good choice. I have never been able (like many people) to "Cascade" them. Let me know how you do this. Lot's of coding for this one but the Hydra has the variable and programming space too.· Does the Hydra (propeller) use interupts (as it was pretty much mandatory for my display) - although if you are using MAX7219 it may not be needed - cascading is your biggest issue (almost no documentation on it) - read the posts about this chip. I have not been able to find any "specific" coding on how to do this other than "general" info on it.

Great idea - I can't wait to see your progress!

Bamse

The choice of 24x24 was simple, I got 10 LED segments for $20 on E-bay, they were actually $5,and the shipping $15...

I'm getting worried about the problem daisy chaining the MAX 7219, I didn't try it on my breadboard...
Just read the documentation and assumed that the data out would just stream the bits through with a 16 bit delay...
By the way, the MAX 7219 were free samples, you got to love Maxim-IC. They sent me two a month so it took a while to get them though...
The brightness is fine even with 2/3 of full brightness, the MAX 7219 is doing a fine job there.
I'm not using the Hydra for power, with a total of 3 Amps (all LED's on full brightness) something would probably break...

Just to keep this thread Hydra-related...

A really cool thing would be to display things like speed, current gear, fuel, life, time, credits or scoring separate on this display.
Or a radar for a flight simulator, music bars, road signs, compass, directions, etc...

I can think of a few things...

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Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

AndreL

I wanted to address your power problem. If raster the leds and only one is on at a time and you refresh the image a zillion times a second then you will get a dim display, but ledable. IF you want to turn on the entire display then you are looking at 3-5 amps, thus you can't use the hydra for power, only control. Your display must have its own power, with common ground to the hydra, then use CMOS preferably to interface the control of the hydra to your board.

Andre'

T&E Engineer

Bamse,

I just·ordered 10 8x8 LED displays for $7 + $10 shipping on Ebay - should be here next week I guess. I would like to use something that can handle more LED's than the MAX7219 (as I have never been able to figure out how to cascade them together). I have 3-4 of the MAX7219 now (2 were free samples from Maxim). I thought I read about a MAX chip that can handle 128 LEDs (but 256 or more would be better).

Any ideas?

Bamse

The reason for the MAX 7219 was the DIP format, I know there are alternatives that are surface mounted...

Try searching on this page, http://www.maxim-ic.com/Display.cfm

MAX6955 seem to be able to drive up to 128 LEDs, maybe I should try get a sample...
I need to get into Surface mounted ICs sooner or later...

I'm biased to Maxim since I gotten so many free samples over the year, but Texas Instuments does have LED drivers as well...

MAX6955, http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3540

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Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

T&E Engineer

I cant order any of the MAXIM 6955 samples as I have reached my max allowance for more 7219 samples I ordered.

Do you have an idea on the TI chips to use?

Bamse

Nope, I haven't tried TI at all...

It took me forever (about 5 months) to get the 10 MAX7219 I needed, keep ordering them and you get like two per month or so...
I think I had to re-order over and over again but it worked...

I know, I'm a cheap bastard...

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Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

LoopyByteloose

I have an 8x8 LED kit powered by an 8051 that has been operating for quite some time. It uses discrete transistors rather than ICs to drive the device.

Scaling up to 16x16 or beyond has been a back burner project for sometime. 24x24 is a lot more ambitious. Because of the one byte microprocessor, it would be easiest to run three 8 bit tall by 24 bit wide lines and have them multiplex [noparse][[/noparse]cycle 1, 2, 3]. Data in put would alternate between the the 3 rows at a speed faster than the eye could see.

Also, having a counter set from 1 to 24 would move to the next column

So it might go Row 1 column 1; Row 2 column 1; Row 3 column 1; Row 1 column 2; and so on.

I am not sure if the MAX7219 would fit into that scheme. I have to read the PDF. I wouldl probably use something like the UNL2803s [noparse][[/noparse]but with a Chip Select feature] for the three ROWs and some kind of adjustible counter IC for the columns.

Andre is right. You cannot power an 8x8 directly from the microprocessor without some dim output or stress. So you need to have each row and column controlled by some kind of power switching [noparse][[/noparse]either included in the ICs or as a discrete transistor]

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"If you want more fiber, eat the package.· Not enough?· Eat the manual."········

···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan

T&E Engineer

I just received 4 free samples from MAXIM of their MAX7219 so I will most likely use these on my new 8x8 LED modules whenever they arrive. Now, if I can only find specific information on how to cascade them.

Bamse

Hope this is not too much off topic but I had no problems daisy chaining two MAX7219...

See my postings in the Replica Forum...
http://www.brielcomputers.com/phpBB2/viewtopic.php?p=936#936

Let's start another thread in the Sandbox forum if we want to continue discuss the MAX7219...

And Yes, sooner or later this display will be hooked up to the Hydra...

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

T&E Engineer

Bamse,

Have you seen my recent posting as of last night on cascading 2 or more MAX7219 ICs to a BS2. I am working on porting this to an SX28 too.

http://forums.parallax.com/showthread.php?p=636061



At the bottom is a schematic and BS2 code.

It's encouraging to see work on the MAX7219 as there seems to be little information on the web on working with it in Non-Decode mode (LED dotmatrix - 64 LEDs).

Start a thread if you wish and I will join in as needed.

Good job on the 6522 / Replica I interface too.