You can do an LED bar graph with a shift register. One SR per bar would need one gpio for each bar plus two gpio for clock and latch for all bars at once. See 74HCT595 or devices specifically for driving LEDs (constant current etc) Many thanks for the reply - it's hugely useful to get different ide...

Alternatively make a lookup table of input value to output bitmask - it costs more in memory (which isn't normally a limit on a Pi), but is faster to lookup. Either method also allows you to apply non-linear representations to your bargraphs - switch between a virtual LM3914, LM3915, and LM3916 at ...

Why not just drive your leds via digital outputs, rather than convert from digital from the Pi, to analogue for the lm3914, which then converts it back to digital for the leds? That seems a rather overengineered solution. Thanks for the reply. I guess because the LM3914 has some nice logic built in...

I'm doing an audio project that requires multiple analogue inputs and outputs: Inputs are to read various potentiometers - I've found the MCP3008 ADC which will do this nicely over SPI. Outputs are to drive bargraph LEDs for a visualiser. I'm currently planning 10 bands, each driven by an LM3914, wh...