Different way to trigger weighing than finger?

is there an alternative way to trigger the weighing to start?
placing the finger is super unstable and has a variance of a couple of grams. if we had "something" to activate the capacitance that was always the same weight, we could measure a lot more precisely. like coins, a specific material, anything?

No files, tests, or entry points are identified. Start by locating how the current finger-based capacitance trigger starts weighing, then investigate whether a consistent external activator can replace it and define how repeatable measurements would demonstrate completion.

Written by the indexing model from the issue text.