next topic »

[on:]

I have an on/off foot paddle I want to connect to latching solenoid. When I press the peddle, I need to send a 100ms pulse to the solenoid. As long as I keep the foot down pressing on the peddle, nothing should change. When I take my foot of, I need to send another 100ms pulse.
The solenoid will open when it get a positive 6VDC pulse and will close when getting a negative (-)6VDC pulse.

I don't really know how to start, but I know I don't want to use a microcontroller and I think a 555 timer can do the trick.

[Reply #1 on:]

I don't want to use a microcontroller

So why are you posting in Arduino forums?

[Reply #2 on:]

Use a h-bridge to drive your solenoide and a 555 as a monostable to generate the pulse. The pulse should do two things, enable the h-bridge and trigger a flip flop. The output of the flip flop should drive the h-bridge direction.

[Reply #3 on:]

But how do I keep it from generating pulses when the pedal is kept pressed?

[Reply #4 on:]

Maybe start here?

http://www.instructables.com/id/Make-an-LED-Blaster/step2/Build-the-555-ic-one-shot-timer/

[Reply #5 on:]

But how do I keep it from generating pulses when the pedal is kept pressed?

All this would be easy with a microcontroller, but noooo....  ]

[Reply #6 on:]

But how do I keep it from generating pulses when the pedal is kept pressed?

You wire the 555 up as a monostable, then you AC couple into it from your foot switch (attach it through a capacitor) then you will only get spikes that trigger the monostable when you press and again when you release.

[Reply #7 on:]

AC couple?

[Reply #8 on:]

AC couple?

http://en.wikipedia.org/wiki/Capacitive_coupling

[Reply #9 on:]

Using a micro controller will take all the fun out of it ;-)

[Reply #10 on:]

Fun... Hell man what you are talking about is hard work, the controller is easy

Bob

[Reply #11 on:]

It might be easy but if I want to make many of these circuits, it means I have to prepare an ISCP connector on my PCB and upload a sketch to each unit, which is time consuming.
I need it to be as small as possible since it needs to fit inside a foot pedal.

[Reply #12 on:]

It might be easy but if I want to make many of these circuits, it means I have to prepare an ISCP connector on my PCB and upload a sketch to each unit, which is time consuming.

a) Soldering a dozen extra components to a PCB is time consuming, too...

b) https://www.adafruit.com/products/394

[Reply #13 on:]

In the long run, an assembly house would do that for me.

I really liked the pogo pins! Didn't know this solution existed

[Reply #14 on:]

In the long run, an assembly house would do that for me.

If you're producing on that scale then the cost of the parts/fabrication should be #1 priority. I'm not sure which would win though, you're only dealing with switches and digital signals so a microcontroller is hard to beat. Atmel makes some really, really small chips for simple jobs like this (six pins).