Added a debounce resistor value calculator.

other/debounce-calculator/Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "debounce-calculator"
+version = "0.1.0"

other/debounce-calculator/Cargo.toml

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+[package]
+name = "debounce-calculator"
+version = "0.1.0"
+authors = ["Mathias Gottschlag <mgottschlag@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

other/debounce-calculator/src/main.rs

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+//! Calculator for hardware debouncing using an RC filter as described in
+//! https://my.eng.utah.edu/~cs5780/debouncing.pdf.
+
+use std::io::{self, Write};
+
+fn main() {
+    let supply = read_float("supply voltage [V]:");
+    let high = read_float("high input threshold voltage [V]:");
+    let low = read_float("low input threshold voltage [V]:");
+    let leakage = read_float("max. leakage [uA]:") * 0.000001;
+    let time = read_float("debounce time [ms]:") * 0.001;
+
+    let c = 0.0000001; // 0.1uF
+    let r_pullup = -time / (c * ((supply - low) / supply).ln());
+    println!("pullup: {} Ohm", r_pullup);
+    let r_pulldown = -time / (c * (high / supply).ln());
+    println!("pulldown: {} Ohm", r_pulldown);
+}
+
+fn read_float(label: &str) -> f64 {
+    println!("{}", label);
+    io::stdout().flush().unwrap();
+
+    let mut input = String::new();
+    match io::stdin().read_line(&mut input) {
+        Ok(_) => input.trim().parse().unwrap(),
+        Err(error) => panic!("invalid input: {}", error),
+    }
+}