If you already own the ebook edition of Mastering ArduinoJson, you can upgrade to the latest edition for free.
If you purchased on arduinojson.org, you should have received an email inviting you to download the new edition. If not, search your Inbox for a mail titled “Thank you for your purchase!”; the download link you received back then should still work.
If you purchased on Amazon Kindle, you’d get the new version if you opted for the automatic updates. Otherwise, you must go to Manage Your Content and Devices, and you should see an “update available” button.
If you purchased on LeanPub, log in and go to Your Library.
If none of these options work, please send me an email; you’ll find my address in the last chapter of the book.
Thanks again for purchasing Mastering ArduinoJson, your support means a lot!