Arduino UNO R4

　Arduino UNO R4 が出るようです。

こちらのサイトに情報があります。
Arduino UNO R4 is a giant leap forward for an open source community of millions


CPU がルネサスの RA4M1 (Arm Cortex-M4) になるそうです。

心配になる今までのソフトウェア資産は、バックワード・コンパティビリティを取るそうですが、うまくいかないところも出てきそうです。
When it comes to hardware compatibility, pinout, voltage and form factor are unchanged from UNO R3, ensuring maximum hardware and electrical compatibility with existing shields and projects.On the software side, a big effort is being made to maximize backwards compatibility of the most popular Arduino libraries so that users will be able to rely on existing code examples and tutorials. In most cases libraries and examples will work out-of-the-box, but a few of them which were optimized for the AVR architecture used in R3 will need to be ported. To help in the transition, Arduino will provide a public list of such libraries, along with links to existing alternatives. In addition, an early adopter program has been launched ? with a dedicated website at www.arduino.cc/UNOR4 ? for library developers excited to find out more about UNO R4 and willing to port their low-level code to the Renesas architecture.