switch type on input??

[yfx4]

For my motorcycle turn signal I need to alter the stock switch mechanism. The contacts are OK for a fully analog system but do not provide consistent contact for a digital one. Since the switch is in a 'box' on the handlebar I will have limited space and POSSIBLE moisture. I considered a magnet on the existing switch lever and either a Hall Sensor or a teeny reed switch to detect proximity of the magnet and trigger the left or right event. I would seal them up in heatshrink or epoxy to waterproof it when tested.

Any other ideas??

Which do you think would be better? The reed switch is simple but I worry about the vibration and since the space is small can I really get the magnet far enough away to open the contacts?

For a Hall sensor do I just connect power to the sensor and the output to the PIC or do I need some sort of interface like this: **broken link removed**

of course I will have a pull up resistor enabled on the pic (right now a 16f1829 but open to change) for stability of the input port.

Thanks in advance!!!

 

[alec_t]

The contacts are OK for a fully analog system but do not provide consistent contact for a digital one.

Perhaps just make the contact 'consistent' with a suitable debounce circuit?

 

[yfx4]

Good point. I'll elaborate further.

The Bike is a Honda VTX with L-off-R on one switch. Stock it latches on and requires a push to unlatch. I want a timed self cancelling system requiring a momentary contact--so I don't ride miles with my TS flashing. Modifying the switch to momentary makes it so the contacts do not consistently contact. The bounce would be easy. Contact not so much. I have disassembled, tweeked, lubed, etc with less than consistent results. I thought adding a weather resistant (for when I wash it or get caught in rain) switch in the existing mechanism would solve the contact issue. Just not sure of the best route though.

 

[KeepItSimpleStupid]

The contacts are OK for a fully analog system but do not provide consistent contact for a digital one.

What do you mean by the above statement?

You have two issues:
1) Provide at least 10 mA of wetting current. That keeps the contacts clean.
2) Provide a hardware of software debounce.

 

[yfx4]

Analog meaning a thermal-based flasher unit that requires the switch to stay in the on position for the flasher unit to work. Digital meaning a system that is programmed and is triggered by a momentary contact switch. The stock switch makes good contact if pushed and held. Not so good if push and release. It is a cheap design with dimpled brass tabs that slide in a plastic carrier. The springiness of the brass provides contact--they get stuck in the plastic sometimes. The vibration of the bike knocks them loose if they sit in place--it just does not function well as a momentary switch. I have seen better contact in cheap slide switches I took apart to see what was inside.

I am probably using the wrong descriptors for the switch.

 

[alec_t]

A monostable circuit could be made which would provide a fixed duration output pulse (e.g. 10 secs) regardless of whether the switch was latched on or made a 'chattering' contact.