Why the duck do cars still have analog speedometers? Surely digital ones would be more accurate and much easier to read without looking away from the road for too long.

https://lemmy.world/post/1562735

Why the fuck do cars still have analog speedometers? Surely digital ones would be more accurate and much easier to read without looking away from the road for too long. - Lemmy.world

Because analog sensors are more accurate than digital ones and that is because they are analog. While an analog system has unlimited resolution, digital systems require a quantization of the sensor data and that is a clear disadvantage when it comes to precision.

“Didn’t understand the sampling theorem” for $2 please.

As long as the frequency of the measured signal is <1/2 the sample rate, you can reconstruct the original signal perfectly.

If you plugged this jaggy-looking graph into a digital to analog converter with perfect analog circuitry, you’d get exactly the sine shown.

I think parent is referring to quantization in the amplitude/y-axis (bitdepth), whereas you are referring to quantization in time/x-axis (sampling rate).

Quantisation is a potential factor but the graph does not show its effects and their comment describes the supposed effects sampling, not quantisation.

Also, when we come to discussing SNR, you’ll have to consider the SNR of analog systems too.

Sorry if I caused confusion by quickly choosing a random graph or maybe by failing to explain what I mean properly. It has been a long time since I learned about A/D and I might probably have mixed up a few details. However - my point still stands - if you look at the graph you will see that the analog speedometer always knows and thus displays the exact speed of the car in any moment (plus a small inevitable speedometer system delay). The digital speedometer on the other hand most of the time shows only the quantized value of the last taken sample - except in the exact moments when the samples are taken.