How to make a thermometer from diodes on Arduino?

Question

Arduino

I'm just getting started with electronics, so don't judge me for what is probably a stupid question.
There was an idea to make a thermometer where a row of LEDs serve as an indicator. Those. the meaning is that we take information from the temperature sensor and, depending on the temperature, turn on the number of diodes we need, we get such a luminous thermometer column.
Of course, connecting each diode to the output pins is inefficient, which raises the question of how this can be implemented by connecting a number of our LEDs to one pin.
The closest analogy that pops up in my head is Christmas tree garlands, which glow in various variations, but are connected in series.

Answer 1

Use shift registers. For example, 74HC595. Here is an article on the topic. On the three outputs of the arduino, you can have as many real outputs as you like (depending on the number of available registers).
And here is another article with diagrams and code directly under the arduino. On it, the use of shift registers is simplified to the point of impossibility.