Never look a gift horse in the mouth

One of the best things about the internet is free stuff!

 

I'm thinking specifically of information and software.

But its sometimes not good enough for some people.

Replacing the DHT22 with a Bosch BME280

I compared the humidity readings from two DHT22 and was alarmed by the difference between them.

Although they are cheap, the Bosch BME280 doesn't have to cost that much more, and provides pressure measurement in addition to humidity and temperature.

Although many of the BME280s available cost around £20, I splashed out £7.61 and bagged a bargain on Amazon.

Raspberry Pi GPIO: Gambas + pigpio library

There are now a number of ways of controlling the Raspberry Pi general purpose I/O.

Libraries such as wiringPi and pigpio are written in the C programming language, but can also be used with other languages including Gambas.

I have covered wiringPi previously, and this short post is just a basic introduction to using the pigpio library with Gambas.

PWM on RaspberryPi with Gambas

The Raspberry Pi has a PWM (pulse width modulation) mode which can be put to use in Gambas with the help of Gordon's wiringPi library.

 

The wiringPi library allows access to the hardware controlled PWM feature which is output on wiringPi pin 1.

So here are some notes and a small Gambas test program to help explore its capabilities.

Raspberry Pi Serial Comms: Gambas + wiringPi

I've been playing around with serial comms on my Pi/Picaxe dev rig.

Using Gordon's wiringPi library makes it easy to open the gpio serial comms port on the Pi and write code with Gambas.

So this post involves writing a simple Picaxe program, and then using wiringPi and Gambas on the Pi to communicate with the Picaxe.

RaspberryPi + wiringPi + Gambas + 16x2LCD module

There are plenty of 16 character, 2 line LCD modules available for home projects using controllers like PICs or Arduino.

In this post I'm using a RaspberryPi with Gambas, while relying on Gordon's wiringPi api to do the heavy lifting.

It turned out to be a bit tricky using the existing wiringPi libraries, but I think I've found a usable work-around.

RaspberryPi inputs: to poll or to interrupt?

One of the best features of the RaspberryPi is the GPIO (General Purpose Inputs & Outputs).

Reading the input levels on the GPIO is pretty easy, especially using Gordon's wiringPi library.

But you need to think carefully about how best to do this in the software for your chosen project.

RaspberryPi Web server: GPIO access

Controlling the RaspberryPi GPIO remotely, over a network or across the internet, seems like an interesting trick.

I copied some code from the net and gave it a try, but unfortunately it didn't want to play.

So I went back to basics and created my own simple test routine.

RaspberryPi GPIO; Using Gambas

The digital IO on the RaspberryPi is very useful for reading switches and turning on relays, lights and driving small motors....

...and controlling the digital IO with Gambas turns out to be really easy.

Here is a very basic example which makes use of the wiringPi library written by Gordon Henderson.