Digital scales generally is a useful gizmo for monitoring common health traits. Moderately than buying an off-the-shelf system, nonetheless, electronics engineering MassimoF11 determined to assemble his personal. His DIY system includes a high-visibility show, together with shutdown performance that ought to enable it to final for over two years on its three-AA battery pack.
For weight sensing, the dimensions makes use of a four-cell Wheatstone bridge pressure gauge and amplifier setup, which is learn by an Arduino Professional Mini. Weight is then proven on a four-digit, seven-segment LED show in kilograms. The rightmost digit shows a tenth of a kilogram. The challenge may, in fact, be duplicated in kilos with the right scaling in code.
Moreover the great high-visibility LED show, the opposite key function of this system is its lengthy battery life. That is enabled by a low-power capacitive activation change, which is the one factor powered in standby. When the capacitive change is touched, it engages a relay that activates the Professional Mini, which in flip holds the relay on by way of an output. After 20 seconds, the Arduino releases its maintain on the relay, powering itself off till referred to as on once more.
Code will be discovered within the challenge’s write-up together with brackets for the load cell and common development recommendation. As seen within the quick video under, it appears like a really purposeful construct. It is going to hopefully function the identical method for years into the longer term earlier than its first battery change!