I'm hoping that a more experienced Arduino designer can confirm my proposed design as feasible.
[u]Objective:[/u] I want to build a gauge dash for my motorcycle that will present fuel level using a 10-LED bar graph and gear indication using a single 7-segment LED display. One design limitation is that the number of wires connecting the displays to the controller must be minimized because the design requires that the displays be mounted externally on the triple tree and the controller mounted internally under the tank. This will require an umbilical cord between the display box and controller, being of the least possible size.
Consequently, I believe that I will have to use shift registers to meet this objective. I have prototyped a design using a shift register for the 7-segment gear display and direct data driving the bar graph. This results in 15 wires connecting the display unit to the controller. This is too many and I'd like to reduce that number.
[u]Proposal:[/u] I saw a design on this forum for a 4x7 segment display driver using non-multiplexed TPIC6B595 shift registers (4 registers each driving one display). This got me thinking that maybe I could make a 3x8 design using the same components, but substitute the bar graph display for two of the 7-segment displays. After all, they are just LEDs. I thought that the data I send to the shift registers at each update interval would be a combination of a font table lookup for the gear indication and a calculated bit pattern for the bar graph.
Does this sound feasible?