What does these symbols in the electric schematic means? I believe the arrow head indicates the direction of flow of current from left device to right device. What is the tail of that arrow symbol is? Is that source of current? What does the diamond symbol indicates here?
This likely indicates signal direction.
- Outward arrow (CLK, DO) - the pins are output-only
- Inward arrow (DI, SCK) - the pins are input-only
- Both ("diamond") (SDA) - the pin is both input and output
The diamond arrow indicates that the signalling protocol is bi-directional.
A triangle arrow head will indicate if the signalling protocol is an input or output depending upon orientation.