Raspberry Pi LESSON 35: Install a Free Office Like Product on Raspberry Pi

Now that we are booting in the Graphical User Interface on the Raspberry Pi, we can explore some useful applications that will run on the Pi. LibreOffice is a free product that will do many of the things Microsoft Office does. This is a great addition to your Raspberry Pi. You can install this product by going to the terminal window, and at the command prompt on your Raspberry Pi type:

$ sudo apt-get install libreoffice

Now the new software should show up under your menu button. The video above steps you through some of the cool features of the product.

Raspberry Pi LESSON 34: Installing Google Chrome on the Raspberry Pi

There is a version of Google Chrome that will run on the Raspberry Pi. I think it is much better than the default browser that comes on the Pi. The key is that the linux version on the Google Chrome download page will not run on the Pi. To get the version that does work, go to the terminal window and at the Linux command line on your Pi and type:

$ sudo apt-get install chromium-bsu

This will take a few minutes but it will install the browser. To find it once you have it installed, look under the menu button, and in the “internet” selection, and you should see “Chromium”. If you right click on it, you can then choose to have it show up on your desktop.

Play around with it, I think it is the best browser for the Pi.

Raspberry Pi LESSON 33: Booting to the Graphical User Interface

If you have been following along in these lessons, we have been operating from the terminal window and the Linux command line. You have learned that you can simply and efficiently do whatever you want from the terminal window. Raspberry Pi does, however have a graphical interface. In this tutorial we show you how to boot in the graphical interface, and then how to find your way around.

Raspberry Pi LESSON 32: Options for Analog Input on the Raspberry Pi

At this point we have learned how to write digital values to the GPIO pins, we have learned to simulate analog out using PWM, and we have learned how to do digital reads from the pins. If you are like me and came from the Arduino world, then you will likely be asking, “Now what about analog reads”. The arduino has pins A0-A5 that make quick and easy work of reading analog values from things like photometers, sensors and various other circuit elements.

The bottom line is, unfortunately, there are no analogous capabilities on the Raspberry Pi. There is no way to directly read analog voltages.

Some suggest incorporating various analog to digital converter chips into your circuits requiring analog reads. For me, my preferred solution is the simply add an Arduino to the Raspberry Pi circuit. There are many very small form factor versions of the Arduino. For example, the nano is very small, and there are some examples that are even smaller. Some of these small implementations can be found for under $10.

If you take this approach, then all you have to do is learn how to communicate between the Raspberry Pi and Arduino either over USB or over ethernet. I show you how to do both of these things in the Lesson series on this WEB site “Using Python with Arduino”. This shows how to communicate between python and arduino using the USB, using Ethernet, or using the Xbee radios. Since python runs on the Raspberry Pi, all the techniques taught in those lessons can be applied to the raspberry pi.

In our high altitude balloon instrumentation package, we actually run a raspberry pi that is controlling two arduino nano microcontrollers. The one arduino is controlling the 9-axis IMU, and the other arduino is running GPS, Temperature, Pressure, and other sensors. The raspberry pi and Arduinos communicate over a small onboard Ethernet switch. The system communicates back to the ground via 1 watt ubiquity bullet radios.

So, the Raspberry Pi should not be viewed as a replacement for the Arduino, it should be viewed as a complementary device that can work nicely alongside the Arduino.

Raspberry Pi LESSON 31: Making a Dimable LED with Python

In this lesson we are ready to bring together a lot of what we learned in earlier lessons. We will create dimable LEDs which will respond to two buttons. If one is pressed the LED will gradually grow dimmer. If the other is pressed, the LED will gradually grow brighter. This will require us to use our skills in using GPIO inputs, pullup resistors, GPIO outputs, and PWM.

For convenience we will use the same circuit we used in LESSON 30, shown below. Also, if you want to follow along with these lessons, you can buy the gear you need HERE.

Raspberry Pi LED Circuit
This Circuit Controls two LED from Push Buttons Using the Raspberry Pi

The objective of this circuit is that we want the LEDs to grow brighter each time the right button is pushed, and we want them to grow dimmer each time to left button is pushed.

The video above steps through and explains this code.

 

Making The World a Better Place One High Tech Project at a Time. Enjoy!