Hey pedward ...... ....... now your simple idea is getting more complicated, I think it's way before that point that we would trade for a shift register mate! (friendly aussie banter)
The cruise control you mentioned though might be built using momentary action switches in which case it is easy to implement a resistor ladder (not R2R) as only one button will be operated at a time. I've used this technique in vending machines many years ago to cut down on the wiring loom for the selection buttons so that each switch is connected to it's neighbor with a resistor plus a common. This resistor string is at maximum value when no switches are pressed and decreases depending upon which tap is connected to ground.
Sometimes I think our digressions, even though we enjoy them, must certainly confuse the OP. Oh well, it's a forum. By all means pedward, don't stop with alternatives, we all love a skeet shoot
You're right on the implementation. There are a variety of specially picked values, and each button is a momentary tap. This was the concept I was originally thinking of when I suggested it.
Similar to the series connected resister string with grounding switches the complementary arrangement is:
The parallel resister arrangement with grounding switches,
In this case the resisters are linearly increased in value. 1R 2R 3R 4R ....
Both of these methods can't distinguish multiple switch closures.
And of course, there is the binary resister network method using single contact grounding switches. 1R 2R 4R 8R 16R ....
This can distinguish multiple switched. However, these resister networks are not very common.
Comments
You're right on the implementation. There are a variety of specially picked values, and each button is a momentary tap. This was the concept I was originally thinking of when I suggested it.
Similar to the series connected resister string with grounding switches the complementary arrangement is:
The parallel resister arrangement with grounding switches,
In this case the resisters are linearly increased in value. 1R 2R 3R 4R ....
Both of these methods can't distinguish multiple switch closures.
And of course, there is the binary resister network method using single contact grounding switches. 1R 2R 4R 8R 16R ....
This can distinguish multiple switched. However, these resister networks are not very common.
Duane J
I wanted to complete the circuit design matrix.
The linear circuits can't distinguish between multiple switches, the binary circuits can.
Duane J