Raspberry

1 Pinout

1.1 Model A and B

1.2 Models A+, B+, PI 2 B, PI 3 B

2 Serial

2.1 Enable

/boot/cmdline.txt
 "console=serial0,115200" 

/boot/config.txt
#enable_uart=0

2.2 Disable

 Remove  "console=serial0,115200"  from /boot/cmdline.txt

If you want to use the uart as IO device, add "enable_uart=1" into /boot/config.txt

Or you can do it by run "sudo raspi-config" , enter "Advanced Options" and then enter "Serial" ....

2.3 Connections

• RASP_TXD --- HEX_TX
• RASP_RXD --- HEX_RX

3 GPIO Control

• https://github.com/joan2937/pigpio
• raspi-gpio
• RAW: http://www.pieter-jan.com/node/15