How do I output level from a bit?

I’m designing a Bit that will have to ourput level, such as could drive a Bar graph, vary the luminosity of an LED, or be used to trigger a threshold. Where is there documentation on the Littiebits bus where I can learn the power available as input and the output characteristics of my bit to trigger the level effects I described above?

TIA
—Raymond

Hi @raygeeknyc,

the typical configuration of a littleBit bit uses an input buffer configured as voltage follower with some protection, the processing part and an output buffer, which is just a voltage follower.
The input impedance and the output resistance resp output current is basically defined by the opamp you are planning to use. Attached is the schematic of the pressure sensor, which is a quite simplistic bit and should therefore show quite well the structure.


The input level is from 0V to 5V, the output level also. The power supply is 5V. Is there something you miss in my explanation?

best regards
7th Dwarf

4 Likes

As 7th says, it’s pretty straight forward. Here is a repository of most of the schematics. Search through Github for more, including design notes and discussion.

Thanks 7th, you’re explanation and your example are perfect.

Thanks Chris - that’s enough reference material to cover all of the bases.