Awhile back, I made an automated weekly timer for my fish tank, to power on the heaters, co2 etc. In the recent weeks, the buttons have not been responding as they used to.
I used Darrel's routine for external interrupts on RB0 to detect button push in combination with other pins. Unfortunately I couldn't use the timers for it as they were used in other parts of the program. Nonetheless the exisiting setup had been working well for the last 8mths.
The buttons are normall held high via 10k resistors and pulled low on button press. I have included the part with the button connections (See attached JPG)
However, I suspect the buttons are not the best, contacts may have corroded over time, sort of cheap and nasty. They have 1.2 Ohm, sometimes 1.8O hm resistance across the terminals on press. The pic sometimes has difficulty detecting this.
Now the sensible thing to do, is to replace the buttons with higher quality ones, right?
Bit of a dilemma, I machined a nice aluminium case for it, so I would prefer not to change the case.
Any suggestions on how to detect presses on a crappy button would be appreciated.
Button with bad contact
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