A method and a control system for controlling rock drilling. Active devices are powered by an EM field and generate a touch stimulating signal that is spread spectrum encoded for identification, and signal pickups in a propagation layer receive the touch stimulation signals which are identified by the DSSS encoding and located using received signal strength techniques. A communications channel interconnects the first control apparatus to a second control apparatus. The Mg\u2014Fe\u2014O ternary-based oxide deposition film has a sulfur-enriched layer containing a higher concentration of sulfur than that of central portion of the iron powder, fine crystalline texture having a grain size of 200 nm or less, and the outermost surface is substantially composed of MgO. An apparatus for implementing the method is disclosed.