There are in all 14 push led illuminated momentary switches...

These are in pairs? On/off/toggle?

..., 5 home brew rotary switches...

How many positions in each rotary switch? And, what are their functions?

...3 toggles.

And these are on/off or on/off/on? Sounds like these won't need anything special except perhaps a reset when the master switch is turned off.

(and a partridge in a pear tree)

Danger! Danger! Weight & balance limits exceeded...

The main panel is built in modules and the ordinary on off functions work a treat with the 74hc74 and 4016's.

OK, so I'm not sure where you need our help then?

I have a lot of components to hand (as I do pcb boards) and the fact of having them do make them more attractive.

It's up to you. There would be a number of advantages to change to a CD4013, and they are not all that pricey - at least not here in the States; I have no idea what you might have to pay in the UK.

Ok if it was just one or two then yes the few pence for the better chip is worth it ...

Not so much that the IC is better; it's how many other parts you will have to buy to get the circuit to do what you want. Might as well just get the "easy to use" IC's in the first place, as you will have to solder everything together. The more joints you have, the more likely something will go wrong.

I am in fact using 74HC74's just too lazy to type it all and I was really only interested in the function of the logic than the peripheral stuff debounce/power supply/decoupling/et al.

Well, all that "peripheral stuff" really does need to be considered.

At this point, I'm not sure of a good way to reset the 74HC74's when the master switch is turned off. Could get messy. It would be a snap with the CD4013's.

I wasn't thinking so much of complete electrical isolation more just a simple way for switching an 'off board' common and input pair.

As long as the supplies all have a common ground/earth, then there isn't a lot to worry about there.

re:LEDs

Yes thanks for the heads up on that one Very good point the actual back lighting LEDs for the panel will be on a variable.

Consider using PWM to control the LED brightness. A variable supply won't work so well, particularly if you have different color LEDs in the mix.

The LEDs on the switches do not have to be bright so I have that covered with resistor arrays.

You'll need current limiting resistors regardless.

My real challenge (if I decide to go that far ) will be to make the 23 x 7 seg displays dim-able. A challenge because the power requirement will alter with differing sets of numbers (how to keep them all the same intensity?).....might leave that out eh?

PWM will take care of that nicely.

I have both flow diags and schematics (of a sort....nowhere as neat as yours but I know what they mean)

Any chance you can post it/them in a form that is intelligible to us?

 

These are in pairs? On/off/toggle?

The push switches actuate various functions some of which cancel a (conflicting) function when pressed ie ya cant have autopilot control both power and speed only power or speed. They are all toggle action ie on the pc they toggle the function and on the panel they toggle the buttons LED.

How many positions in each rotary switch? And, what are their functions?

The rotary switches are for incrementing settings like speed altitude etc and actually don't rotate any more. They simply have a self centering spring and a cam which pushes either of two momentary switches (in this case micro switches) when the knob is turned again to simulate key presses and possibly utilise the type repeat function only that would cause more work to get my panel displays to match the program .On the panel counters are used to increment the displays..its easy to just 'rock' the switch to get the count and similar in action to turning a real knob.

OK, so I'm not sure where you need our help then?

The help needed was primarily the logic to have the flip flops cancel each other (was doing my head in) which you kindly provided.

At this point, I'm not sure of a good way to reset the 74HC74's when the master switch is turned off.

I think I might have got that cracked using bi lats again.... a few mins on a breadboard will tell


As long as the supplies all have a common ground/earth, then there isn't a lot to worry about there.

re:LEDs

Consider using PWM to control the LED brightness. A variable supply won't work so well, particularly if you have different color LEDs in the mix.


You'll need current limiting resistors regardless.

PWM will take care of that nicely.

All the back lighting are white LEDs
But very good idea re PWM's i might have a play!!

Any chance you can post it/them in a form that is intelligible to us?

Ermm There's a LOT of it ...I might if I can make it readable..I know my circuits aint always elegant but usually they work *grin*