Improve the tutorial

index.md

@@ -26,45 +26,68 @@ Microcontroller programming framework.
 
 - [https://github.com/picoruby/R2P2](https://github.com/picoruby/R2P2)
 
-#### Quick demos
+### Tutorial of R2P2
 
-##### 1-1 Getting start with R2P2
+#### 1-1 Getting start with R2P2
+
+- Download the latest `R2P2-*.uf2` from the releases page of the repository
+- Drag and drop it into the RPI-RP2 drive
+- Open a proper port in your terminal emulator
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/s4M4rBnPSus?si=--2VC4Od8wssmHUs" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
 
-##### 1-2 R2P2 shell has some UNIX-like commands
+#### 1-2 R2P2 shell has some UNIX-like commands
+
+- Try some UNIX-like commands like `ls`, `mkdir` and `touch`
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/ISU6TbIoIlQ?si=VL2SBugfvCiDQgXx" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
 
-##### 1-3 R2P2 has PicoIRB
+#### 1-3 R2P2 has PicoIRB
+
+- Open PicoIRB with `irb` command
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/2ZKpOOjzKJc?si=jisnwrIq8FRYuOWq" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
 
-##### 2-1 LED blinking (L-chika) with PicoRuby
+#### 2-1 LED blinking (L-chika) with PicoRuby
+
+- Turn on the on-board LED using PicoIRB
+- If you use "Pico W", write `led = CYW43::GPIO.new(CYW43::GPIO::LED_PIN)`
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/qbs25xDu7t8?si=zcAU2jCnh-boiyow" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
 
-##### 2-2 `require "adc"` loads ADC class
+#### 2-2 `require "adc"` loads ADC class
+
+- You can load pre-built libraries like "picoruby-adc" and use ADC class
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/dPGCyQrX6Zg?si=jHUfKimEBT-Hy7qP" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
 
-##### 3-1 PicoIRB has multi-line editor!
+#### 3-1 PicoIRB has multi-line editor!
+
+- That's cool, right?
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/PVkP_uNBOo0?si=wDVw0IofVLliIoxQ" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
 
-##### 3-2 PicoRuby has Time class working with RTC in MCU
+#### 3-2 PicoRuby has Time class working with RTC in MCU
+
+- The clock will be persistent if you connect a battery-driven RTC module. Try it :)
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/0uj4m4RI7lE?si=r-2cBloVC9x_YsTZ" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
 
-##### 3-3 You can even use a Vim-like editor in R2P2
+#### 3-3 You can even use a Vim-like editor in R2P2
+
+- It's not for a serious usage but for demonstrating the viability of PicoRuby ;)
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/X1RdA6IE780?si=IQwKJFjDSUemjCde" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
 
-##### 3-4 You can drag and drop your Ruby script from your laptop
+#### 3-4 You can drag and drop your Ruby script from your laptop
+
+- This is what you want to do in a real development
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/7nHNEUZnuKQ?si=ozardWECykiTqGU2" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
 
-##### 3-5 /home/app.rb automatically starts Pi Pico
+#### 3-5 /home/app.rb automatically starts Pi Pico
+
+- Now your Pi Pico is a stand-alone device
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/6_RomLChvYE?si=uc4Ec2GKRjLuXxBQ" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>