Expanding Raspberry Pi 3 WiFI range with external antenna

With appearance of Raspberry Pi 3 the new wave of hacking begun. This time the attention falls on new WiFi functionality. As wardr states: “It’s not clear why an external antenna is not an option for the Pi 3 ”. Having said that he thought why not including one by himself. He found that there can be two options of including external WiFi antenna. One could be more barbarian – just remove chip antenna and solder it to left top mount pad. This is more messy part as you need to scratch ground plane to make it possible soldering copper mesh. Another way is more civilized. On the bottom side of Raspberry Pi 3 there is two exposed pads where U.FL connector almost fits. Yet you still need to clear… Continue reading

Using Raspberry Pi sftp server

There are several ways of accessing Raspberry Pi files through network. One of preferred ways is to use Secure Copy (SCP). This is a file sending command allowing transferring files over SSH. This is secure way of sending files between Raspberry Pi boards or other Linux machines. In order to use with Windows you need special software like WinSCP. So as you can see it requires additional software to access files from windows. But if you are used to transfer files via FTP, then you have another option – SFTP which is an FTP with encryption. SFTP is already enabled in Raspbian and can be used right away. Be sure that your FPT client supports sftp protocol. For instance FileZilla, Bitvise and same WinSCP clients work without problem. In order… Continue reading

Internet connected power usage monitor

Our homes are filling with energy hungry devices. Some of them are constantly active like fridge, routers, lighting, some switched off or on stand-by. Each of them takes some portion of energy that reflects on the end month bill. Some things you can control, but some not. So in order to hunt inefficient nodes you need some sort of energy usage monitoring. You can find lots of implementations where some are simple indicators, other are advanced and web enabled. TSalwach @ github.com have built his own version of energy monitoring system which looks really promising. His implementation monitors all three phases where he extracts several parameters: RMS Voltages and currents on each phase Apparent power (product of RMS voltage and RMS current) Real (active) power Reactive power with inductance/capacitance indication… Continue reading

Python web server in Raspberry Pi

There are many ways of serving web pages from Raspberry Pi. One of the ways is to install Apache web server software. This is still a standard solution for most of purposes. These things require quite some performance and this is not always an optimal choice. If you need simple webserver for your home project that would easily work with GPIO you could try Python web server. Python web server relies on flask – an extension that provides web microframework. It allows building and rendering webpages with few lines of code. Sankar have written a short tutorial on how to start with simple static webpage from Raspberry Pi. From there you can move on with more advanced pages that include dynamic content and so on. Continue reading

Tearing Raspberry Pi Zero apart

Raspberry Pi Zero is really minimalist but yet powerful minicomputer featuring all necessary parts required to run Linux or other operating system. It features Broadcom BCM2835 processor at 1GHz, 512MB of DDR2 RAM, micro-SD slot, mini-HDMI capable to output 1080p60 video, micro USB for data and power, 40-pin GPIO, unpopulated composite video. All this fits in to 65mm x 30mm x 5mm form factor. Price for it is ridiculously low – $5. you may need micro-USB to USB adapter and HUB if you would like to have WiFi functionality, or connect keyboard. It is ideal small embedded Linux based board that is more power efficient than standard Raspberry Pi boards and still can run powerful control applications. Lets leave this topic to other debates. electroupdate shared his video where he… Continue reading