His solution is to repurpose an analog multimeter. The meter is interface with the toggle pin and a trimpot calibrates the needle. This way the needle jumps when the processor is busy and returns ...

Multimeters can be as cheap as $10.00 but go up to thousands for professional, laboratory-quality ones. You can buy an excellent multimeter of sufficiently tough build quality and functionality ...

But what if instead of a cheap-and-cheerful bench instrument your needs extend to a high-precision device, a really good multimeter? It’s a path [jaromir.sukuba] has trodden with his 6.5 digit ...