16 Sharp IR sensors on Arduino Mega

i wanting use 16 sharp ir sensors on arduino mega.  sharp sensors sharp 2y0a21 f 4y.

it's power consumption typically 30ma per sensor

my sensors have 3 wires, +5, ground, , signal

i have of +5 connected , connected +5v terminal on arduino
i have of ground connected , connected ground terminal on arduino
each of signal wires connected 1 of analog pins a0 a15

when read values of sensors connected, crappy readings
when read 1 value 1 of sensors connected, results

so determined should use external power supply, connected 5v 2.5amp power supply barrel plug on arduino mega.  reading data got little better, still isn't usable.

should try wiring 5v 2.5amp source directly down +5 , ground buss have of sensors , connect ground of bus ground on arduino?

or there limitation of arduino coming in contact with?

quote from: datcomputerguy on apr 15, 2015, 08:20 pm

should try wiring 5v 2.5amp source directly down +5 , ground buss have of sensors , connect ground of bus ground on arduino?

yes. arduino's regulator enough atmega328p on board (and whatever may sourcing or sinking) - -not- meant powering external devices (beyond basic demonstrations).

also - need minimum of 7 volts barrel plug regulator stable , output 5 volts under load.

if power supply -truly- regulated supply, , want power arduino 5 volts, you'll need go through usb port (don't try run power +5v pin; have wrongly suggested in past - you'll damage or blow regulator doing that, unless make modifications board, take regulator out of loop - , couldn't use barrel jack then).

otherwise, tie grounds together, , run sensors supply, , arduino usb port - or via barrel plug power source supplying 7 volts or more @ 500 ma (just margin).

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