Arduino Uno Hardware Manual Errata

29 December 2020

Report errata for the Arduino Uno Hardware Manual, First Edition in the comments section of this page.

Newer book available:
The Ultimate Arduino Uno Hardware Manual is a replacement for the Arduino Uno Hardware Manual. It is revised, updated and printed in full color.

The Arduino Uno Hardware Manual is no longer available – buy the new Ultimate Arduino Uno Hardware Manual instead. This page has been left here to provide support to those readers who own a copy of the older Arduino Uno Hardware Manual.

Errata submitted to the comments section are included below.

Page 79 – Incorrect Calculation

2.7.5.3 Calculating Analog In Voltage

The second sentence in the first paragraph of section 2.7.5.3, at the top of page 79, reads as follows:

On the Arduino Uno we know that the default reference voltage is 5V, so the calculation becomes 1024 ÷ 5 × <analog value read on pin> = voltage.

The part shown in bold above is incorrect, it should be 5 ÷ 1024 which is how it is shown in the sketch that follows – the sketch that follows is correct. The sentence should therefore read as follows:

On the Arduino Uno we know that the default reference voltage is 5V, so the calculation becomes 5 ÷ 1024 × <analog value read on pin> = voltage.