Addressable LED modules

[pindar]

I want to make a small, cheap module that will allow me to control a single LED based on a serial bus transmitting an address. (either from a PIC or preferably a PC- say ultimately from USB or RS232) I want to be able to daisy chain these together to have hundreds (thousands?) of individually addressable LEDs. The LED state should latch so that only state changes are transmitted.

I'd like to minimise the cost of the boards, as well as size, and the number of wires on the bus. (Just power, ground and serial in?) The bus should be able to drive over a few (3-4?) metres.
The system could be broken down into groups where group master circuits are addressed (over any kind of connection) and each one drives only a few sub-addressable LED modules, over separate 3-wire busses.

There are several similar projects out there such as
https://www.electro-tech-online.com/threads/how-to-control-with-250-light-diods-by-printer-port.2419/?highlight=addressable
or https://www.electro-tech-online.com/threads/individually-addressable-lights.12824/?highlight=addressable
but none seem to really match my criteria- each module should have just one LED.

Ideally I'd actually have variable intensity and/or RGB LEDs (say 24 bit colour?)

Assuming that I or someone out there can come up with a suitable addressable design, what is the best (smallest/cheapest) way of coding an address? e.g. breaking PCB links rather than using a DIP switch? And then matching that address?

Thanks

 

[picasm]

A Maxim/Dallas DS2406 1-wire dual addressable switch appears to provide some of the functions you require and comes in a small to92 package.
Could be expensive though unless you buy them in bulk.
**broken link removed**

 

[Nigel Goodwin]

Requiring just a single LED on each board is going to make it expensive, no matter how you do it - but it's simple to do with a PIC - for one LED per board the tiny ten pin SM ones would be all you require. Each individual address could be hardcoded in the program, or stored in EEPROM (if the 10F series have it?).

 

[weazle]

Anyone had any luck?!? I was thinking of using 8-bit shift registers, using a carry out(from a counter perhaps?) to shift to the next register, and so on.... this way you get the control of 8 led's per chip versus one per chip. Only issue is the software, no clue on how to write serial software to address thousands of led's in this fashion....

Is there an 8-bit serial shift register that has eeprom onboard to program serial addressing? Perhaps programmable via USB?

 

[weazle]

Duplicate post - sorry!

 

[weazle]

How about a chip that is 32-bit output, serial input? Setup 2 of these so you have an array 32x32, thus giving you 1024 LED's to control?!?

Here's an example: http://www.datasheetcatalog.org/datasheet/allegromicrosystems/5833.pdf

One serial input, 32 individual outputs driving your "column" of the array, one more chip controlling your "rows" of the array. I'm sure with some inverters and transistors, you could make this work and also get high current, ultra-bright LED modules working with the transistors.

QUESTION: is there any "good" software out there for 32-bit and greater serial programs?

 

[Ubergeek63]

I want to make a small, cheap module that will allow me to control a single LED based on a serial bus transmitting an address. (either from a PIC or preferably a PC- say ultimately from USB or RS232) I want to be able to daisy chain these together to have hundreds (thousands?) of individually addressable LEDs. The LED state should latch so that only state changes are transmitted.

I'd like to minimise the cost of the boards, as well as size, and the number of wires on the bus. (Just power, ground and serial in?) The bus should be able to drive over a few (3-4?) metres.
The system could be broken down into groups where group master circuits are addressed (over any kind of connection) and each one drives only a few sub-addressable LED modules, over separate 3-wire busses.

There are several similar projects out there such as
https://www.electro-tech-online.com/threads/how-to-control-with-250-light-diods-by-printer-port.2419/?highlight=addressable
or https://www.electro-tech-online.com/threads/individually-addressable-lights.12824/?highlight=addressable
but none seem to really match my criteria- each module should have just one LED.

Ideally I'd actually have variable intensity and/or RGB LEDs (say 24 bit colour?)

Assuming that I or someone out there can come up with a suitable addressable design, what is the best (smallest/cheapest) way of coding an address? e.g. breaking PCB links rather than using a DIP switch? And then matching that address?

Thanks

a single flip/flop, power, ground, data in, data out, and clock... 4 wires, no addressing. for RGB drive a single 8bit shift register for 255 colors.


why do you need it addressable? with a ten mhz clock you could drive 1,000 LEDs 10 times a second at a 99% duty cycle.

dan

 

[elfcurry]

I know of one type of individually addressable RGB LEDs - WS2811 and WS2812.
The former is just a control chip but the latter have the RGB LEDs built into a 5050 chip.

24-bit colour data for each LED is passed along through each to the next, so long strings can be controlled with 4 lines: power data in and data out but possibly large abounts of data and rather fiddly timing.

I've ordered a few to play with.