/diy/ - Do It Yourself

I've been stuck on this snag for 3 weeks now.

I'm making a small device I solder onto a synthesizer that can control 5 pots via an arduino.

The 5 chips at the bottom are mcp41010 digital potentiometers. They're active-low SPI devices. The unconnected pins are Terminal2, Wiper and Terminal1.

The big chip on the top is a 74hc4051, an active-low multiplexer being used to activate the MCP41010s individually via their Chip Select pins. The 4051 is pretty straightforward, with A being the common pin routed to a0-a7, determined by the values passed to s0-s2, which are connected, even though i didnt draw it on the schematic im sorry.

The code is extremely simple: cycle through each combination of s0-s2 pins, each time sending a rising value over SPI, when it reaches 255, it starts over at 0.

The problem is, It only works for the furthest-right digipot. The rest of them do nothing.

Any ideas?