Raspberry Pi or Arduino for a wireless ultrasonic fuel level sensor over Wi-Fi?

Hello
I have the following problem: I want to monitor the fuel level (coal) in the central heating boiler in the cellar.
My assumptions are as follows:
- an ultrasonic distance sensor will measure the fuel level
- a microcontroller will make the reading available wirelessly (preferably via Wi-Fi) over IP
- optionally, it will also support an additional temperature sensor

I was thinking of using a Raspberry Pi with a USB Wi-Fi module, but it doesn’t have analogue inputs for the distance sensor; besides, I like the fact that it runs on Linux and is fully network-compatible.
Or perhaps an Arduino would be better – here I can connect whatever sensor I want, though the downside is that connecting to Wi-Fi can be problematic, and changing the software requires connecting to a PC.

What would you recommend?

PS. I came across a distance sensor with a serial interface somewhere, but I’m still looking into it.

...The cheapest option would be some sort of GSM module (or an old mobile phone) and a microcontroller.
Anyway, there are already kits like that on all___o, so maybe it’s just a case of having a look?

This topic has already been discussed at length (https://www.elektroda.pl/rtvforum/topic1549299.html). In the case of coal, the matter is not quite so straightforward, as it does not form a flat surface. A standard ultrasonic sensor is unlikely to be the best solution.

Thanks for the link to the thread; there aren’t any solutions there, but the ideas are interesting.

Actually, I was really more after some advice on which controller to use.

I understand, but I agree with the views expressed by previous contributors and, of course, I reiterate my own view that measuring the level of carbon and similar substances is not straightforward, as they do not form a level surface. We need to start by resolving this problem.

A carbon level tolerance of 5–10 per cent is not a problem, although I don’t want a simple indication such as ‘high’, ‘medium’ or ‘low’; I would prefer a linear measurement.

First, you need to check the sensor you’re planning to use and see what it shows.