CategoryRaspberryPi - rudiswiki9

HowTo for the Raspberry Pi Linux computer

The Raspberry Pi is a credit-card sized computer that plugs into your TV and an USB keyboard and an USB mouse. It’s a capable little PC which can be used for many of the things that your desktop PC does, like spreadsheets, word-processing and games. It also plays high-definition video.

Because it is so cheap (about 40 EUR), it is very attractive to use it in all kinds of embedded computer projects.

The main page for Raspberry Pi information is here.

My first serious application for the Raspberry Pi is a Multi Media Center, see RaspberryPiXBMC .

Config

If you have a need to do later a basic configuration use the terminal:

$ sudo raspi-config

Tipps

Problem with Flicker in the HDMI video and periodic shutdown (black screen)
- the +5 V power supply is weak (< 4.7 V)
- Try Interference_visible_on_a_HDMI_or_DVI_monitor
- Edit file /boot/config.txt and remove comment:
```
  $ sudo nano /boot/config.txt
    config_hdmi_boost=4
  # save file

  # reboot Raspberry Pi
```

LCD Display with I2C Bus

In order to attach a low cost 4 x 20 character LCD (HD44780 controller, see picture), to the RaspBerry Pi, an I2C bus interface is very usefull, because it needs only 2 control lines. The connection is Arduino compatible, see at the Links.

One drawback is the power supply. The LCD needs 5V to operate, but the I2C bus has 3,3V only. The PCF8574 data sheet says HIGH level is 0.7 x Vdd = 5 x 0,7 = 3.5 V, in my case it works.

Fortunately there is also a Python3 library free available, see at the Links. To match the Arduino schematic the init line should be:

lcd = i2c_lcd.i2c_lcd(0x20, 1, 4, 5, 6, 0, 1, 2, 3, 7)