TrackerBlock is a Mesecons Addon that adds two nodes, Tracker Blocks and Block Checkers. The Tracker Block follows and player that is 3 nodes above it and the Block Checker outputs a mesecons signal when there is a Tracker Block above it.
Note: The red lamps nodes are Red Lightstone from Mesecons, and not included in this mod.
The recipe for a Tracker Block is 4 stone around the corners of the crafting grid, 4 mesecon wires on the middle sides of the grid, and one Mese Crystal in the center. The recipe for a Block Checker is 3 mesecon wires along the top, and the rest of the grid filled with stone.