Fault detection devices, systems, and methods are provided which implement identical processors. A first processor is configured to receive a first measurement, execute a first firmware based on the first measurement, and output a first result of the executed first firmware. A second processor is configured to receive a second measurement, execute a second firmware based on the second measurement, and output a second result of the executed second firmware. The first firmware and the second firmware provide a same nominal function in a diverse manner for calculating the first result and the second result, respectively, such that the first result and the second result are expected to be within a predetermined margin.