AVR External Memory Interface (XMEM) reads input matrix

scanning-48-key-matrix

Reading from a large number of inputs, like this piano keyboard, can be tedious. Even when multiplexing there's a lot to keep track of. But if you choose the right microcontroller, you may have hardware assistance. Here's an ATmega640 is using it's external memory interface to read the key matrix. You may remember the Open Music Labs article about reading from a shift register using just one … [Read more...]