This is related to another question I've just posted (What's the purpose of a ferrite bead inductor on this circuit?), regarding the battery charger described in the AVR450 Application Note – Battery Charger for SLA, NiCd, NiMH and Li-Ion Batteries, which one day I hope to build.
On page 40, there's a schematic showing the MCU connections (picture below). Marked in red is a 0Ω resistor that is puzzling me. I suspect that it is just a wire jumper linking
GND. But I don't understand why there's a jumper there.
- What does the jumper represent?
- Why are
GNDseparated like that?