L
linnix
- Jan 1, 1970
- 0
We are working on short range (5cm to 10cm) proximity detection.
First of all, I still think MEMS IR sensor is the way to go.
But it would take time to build, so perhaps next year.
Meanwhile, we are trying capacitive sensor using a 555 timer.
Based on input capacitance, the 555 output a periodic signal
monitored by a microcontroller.
The circuit works somewhat, but only when close to the
timer chip. The question is how can we isolate the trigger
pin and attach it to external detection plate.
Apparently, most of the electrostatic fields leaked between
the pins (trigger and ground) of the chip, so external plate
does not help much.
Thanks for any suggestions.
First of all, I still think MEMS IR sensor is the way to go.
But it would take time to build, so perhaps next year.
Meanwhile, we are trying capacitive sensor using a 555 timer.
Based on input capacitance, the 555 output a periodic signal
monitored by a microcontroller.
The circuit works somewhat, but only when close to the
timer chip. The question is how can we isolate the trigger
pin and attach it to external detection plate.
Apparently, most of the electrostatic fields leaked between
the pins (trigger and ground) of the chip, so external plate
does not help much.
Thanks for any suggestions.