[jakep]

No, your code will not work. The reason is that the analog signals sent out by the digipots and the OI are not sensitive enough to accurately measure a 1 bit difference on an analog port. The max we had good results with was 4 digital outputs on one 8bit analog signal. The reason it is 0x87 is to provide an offset so that if there is a difference of 1 bit, it won't erroneously send button signals.