RPi.GPIO basics 2 – how to check what Pi board Revision you have

 Input and Output, interfacing, python programming, raspberry pi  27 Responses »
Jul 122013
 
RPi.GPIO basics 2 – how to check what Pi board Revision you have

It all started in September 2012. The Raspberry Pi Foundation went and made some improvements to the Pi. How dare they!! ;) Seriously, though, there were some significant improvements to the Pi and a Rev 2 version was launched with double the RAM and some other changes/additions/improvements. This threw up some minor headaches for developers because some of the GPIO pinouts were changed and some new GPIO ports were made available on a brand new “solder it yourself if you want it” header called P5 (see the leaning header of Pi5a) GPIO 0 became GPIO […more…]

RPi.GPIO basics 1 – how to check what RPi.GPIO version you have

 Input and Output, interfacing, python programming, raspberry pi  15 Responses »
Jul 112013
 
RPi.GPIO basics 1 - how to check what RPi.GPIO version you have

It struck me the other day that I’ve published some fairly advanced RPi.GPIO tutorials, (e.g. interrupts and PWM) but not done anything more basic, apart from the Gertboard examples. So here’s an attempt to remedy that situation. Over the next few days, we’re going to have a walk around Ben Croston’s RPi.GPIO, which is now at version 0.5.3a. Some of this stuff may be new to you even if you’ve been using RPi.GPIO’s more advanced features, so it’s worth having a look. What is RPi.GPIO? It’s an easy way of controlling the Pi’s General Purpose […more…]

How to use soft PWM in RPi.GPIO 0.5.2a pt 2 – led dimming and motor speed control

 Electronics, Input and Output, interfacing, python programming, Raspberry Pi Hardware  38 Responses »
Apr 212013
 
How to use soft PWM in RPi.GPIO 0.5.2a pt 2 - led dimming and motor speed control

In part 1 of this series, we looked at the basic commands for using software pulse-width modulation (PWM) in RPi.GPIO 0.5.2a and higher. In this article we’ll get a bit more hands-on and into some practical applications for it. It’s all very well being able to make nice square-wave pulses on an oscilloscope, but what’s it actually useful for? Our servo said? EEEEH AAAAH I tried using RPi.GPIO soft PWM with servos in response to a query after the last article, but, although it did change the servo positions, it was jittery. Servos require quite […more…]

RPi.GPIO 0.5.2a now has software PWM – How to use it

 Input and Output, interfacing, python programming, raspberry pi  45 Responses »
Apr 072013
 
RPi.GPIO 0.5.2a now has software PWM - How to use it

Over the last couple of weeks the pace of development for Python programmers who like to dabble in GPIO has gone up a gear. Both main GPIO systems for Python on the Raspberry Pi have been getting some enhancements. RPi.GPIO, now at version 0.5.2a, has interrupts and threaded callback capability. You will probably have seen my three recent posts showing how to use those. WiringPi for Python version 2 is in Beta testing. I discovered two bugs while I was trying it out. Both of those have been squashed. One by Gordon “Drogon” Henderson in […more…]

How to use interrupts with Python on the Raspberry Pi and RPi.GPIO

 Input and Output, interfacing, python programming, raspberry pi  90 Responses »
Mar 172013
 
How to use interrupts with Python on the Raspberry Pi and RPi.GPIO

The latest big news in the world of Raspberry Pi Python GPIO programming is that Ben Croston has released an update for RPi.GPIO. Why is that a big deal? Because this version has interrupts. “What’s an interrupt?” I hear you say. It’s a way of waiting for something to happen without checking constantly whether or not it’s happening. Imagine that you’re waiting for a delivery – something you’re really excited about – like a Pi camera.You spend far too much time looking down the street in eager anticipation of the postman’s arrival. You can’t fully […more…]

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