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Poor mans LED controller?

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ids:

Added the 238 (attached)

Unstupid:

I have some flip flops for you but I don't know if it's going to be of much use!



ids:

Perfect - how much you asking?  By the way, I only need the left one....and 8 of them  ;D

MonMotha:

The trick when using the addressable latch is to bus the address inputs but connect one unique data line to each latch.  This means that a write will still update 8 bits, but it will update a single bit on all 8 latches rather than all 8 bits on a single latch.  It's equivalent to the 238+574 solution, but the update order is different, and you save one chip.  There's also less bussed wiring (4 wires rather than 8).

Also, you might look into the TPIC6A259, TPIC6B259, and TPIC6259 (I'm not sure all of these exist).  They have different current handling capabilities and wil have different prices.  Same with the TPIC6273, TPIC6A273, TPIC6B273, and TPIC6C273.  TI will probably sample these to you for free (including shipping!), too, but they may limit you to 4-5 pieces.

The classic way to run busses on perfboard is to "weave" the bus along using uninsulated/tinned bus wire (hence the name) the length of the board, then tap jumpers (insulated except on each end) from the bus lines to the chips in question.  If you prefer to use all bus wire, you can just make sure that the bus is on the opposite side of the board wherever there would be a crossing.

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