Hi,

The simple answer is yes, you can combine the signals from multiple sensors using OR (active bumper state high) gates; haven't thought through using ANDs (ANDing all sensors and inverting the output ?).

Be careful if you decide that only one bumber can be active at a time or that only certain combinations can be and combine in signals from them using XOR. Example: square robot with 4 bumbers; one each on front, back, left and right sides. When will the left and right bumpers ever be active together ? Going through a closing door - seen this happen, robot spinning wheels thinking nothing is wrong. Further more, 2 sensors per side requires that that when a robot decides to turn in a confined space it might be necessary to tell to adjacent sides have collided; whether corners of the rotating robot have activated.

You would probably be better off knowing when a bumper changes state (from idle to active or from active to idle). This way you would be able to handle hitting something and knowing when you have reversed away from it enough to deactivate the bumber :) Off the top of my head: having some kind of latch that recorded the state of the bumber inputs when the interrupt was cleared. The raise interrupt logic could XOR the current bumper state with the previous state of the bumper as held by the latch. When a bumper changes state the XOR of the previous value (latch) and the new state would produce a 'high'. ORing all results of the XORs of current and previous bumper states together would raise an interrupt when bumpers change state. Once processing the sensor interrupt is complete, latch the current values of the sensors and wait for the next interrupt to occur - when a bumper changes state.

Hope you find that some help.

Cheers,

Luccus