fix error: missing compiler version 5 on Keil

 1. Download Arm Compiler 5

link: google drive

2. Install Arm compiler 5

Extract and Run "setup.exe" file.

Create new folder "ARM5" inside "C:\Keil_v5\ARM" path.

3. Add Arm compiler 5 into Keil

4. Select Arm Compiler 5 as default

References:

Arm Compiler downloads index