[TriEmbed] Chain-able EEPROM or Similar

[Adam Haile]

Oh... yeah. Important part. The data in the chip needs to be non-volatile!
So, the data would be stored on each chip individually and then read
serially.

On Mon, Nov 30, 2015 at 2:07 PM, Brian <triembed at undecidedgames.net> wrote:

> If you can spare three pins, shift registers are (maybe) exactly what you
> need.
>
> You didn't mention how the bytes get there to begin with, which does
> affect the answer.
>
> Most (?) serial-out shift registers support chaining out-of-the-box; they
> have a latch signal to preload their internal flip-flops as well as an
> external serial input.  By their very nature, the first (n) bits clocked
> out will be their own bits, followed by whatever bits clock in on the
> serial input.  Natural chaining.
>
> If you have parallel inputs that can all be latched at once, a single
> latch + clock-out + data-in is all you need on the host MCU.
>
> If the data comes into the registers serially, well, that's a bit more
> complicated.
>
> -B
>
>
> On 11/30/2015 1:35 PM, Adam Haile via TriEmbed wrote:
>
>> I have /no/ idea if this technically is something that exists, but I
>> have to imagine it's possible.
>>
>> I need a small, cheap (isn't it always?) chip that can store a few bytes
>> of data. Actually a single byte is all I need. And can be accessed kind
>> of like a shift register where I can query an unknown number of devices
>> int the chain and get, in order, the byte that each one stores.
>>
>> The intent here is  so that I can have multiple, pre-wired, sets of LEDs
>> with an arbitrary order and number of LEDs on each. This chip would
>> store the LED count for each pre-wired section. Without knowing anything
>> about the pre-wired sections, I need to be able to poll all these chips
>> and from that know how many pre-wired sections there are, how many LEDs
>> each has, and in what order. The data returned just needs to basically
>> look like: 48, 36, 24, 18 (4 sections with 48, 36, 24, 18 LEDs, in that
>> order).
>>
>> I assume it would use an SPI-like interface... not exactly since I can't
>> use chip selects. Since I would have an arbitrary number. A 2 wire
>> interface would be great. Is it possible to do something like this with
>> I2C? Basically, I know what I need, but don't know what to call it.
>>
>> Any thoughts?
>>
>>
>>
>>
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>
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