I recently created a printed circuit board for a raspberry PI design i’m working on. By the past, when I did such things, the cost to make it was not accessible for a home made design. In 10 years things have change a lot and now, you can do it for less than 100€ for a 10×10 two layer board. 4 layer is also something accessible.
I want to share with you this experience, because, I had a good and an bad experience to share.
After mixing different source of information, I was able to decode some Oregon Scientific sensors to get Temperature and Humidity indication, over the air, on 433.92MHz, with a Raspberry PI system. This article gives some details of this adventure …
You follow this implementation at your own risk…
If you are interrested in this article, you could also take a look here where you can find a RF433 shield and the associated code
After having test some receiver, naturally, I’ve tested some transmitters, the objective is the same : get the best coverage in the same condition : I would say poor conditions. Lots of wires going every where and an antenna make with a simple 17.3cm wire. As expected, results vary regarding the emitter used. Reed more to get details.
MQTT (MQ Telemetry Transport) is a Message Queuing system for machine to machine communications. It allows communication of mobile systems over high latency, low bandwidth and poor quality networks. It manage communications over TCP (not over Http) to optimize the size of messages and it manages different quality of services. Depending of it, messages can be dropped, received multiple times of you can have the insurance to receive the message one and only one time.
It makes this protocol really interesting for the communication between a raspberry PI and a server when this communication is event driven and the communication link looks like a Edge/3G channel.
Mosquitto is an open source implementation for MQTT.
Here are some tips on how I implemented it, for a demonstration purpose
Tonight, the hack objective is to communicate with 433Mhz equipments using Raspberry PI. For this, I use a 433Mhz receiver from Itead Studio bought at hack spark for 4.5€ with an emitter. Cabling is simple : VDD on 5V (I tryed to use 3.3V supply voltage but as a consequence the reception range is limited to a couple of cm) , GND goes to GND and One of the data pin going to pin 13 (gpio21/27). This is following elements found on that site : ninjablocks
If you are looking for a RF433 shield for Raspberry, check this link to another article !
The first step is to install a fresh wheezy raspbian environment and get the basis element to work :
Some new hacking on Raspberry PI, the objective is to get a TC74A5 3.3VAT temperature sensor working with a RPI. This sensor is a digital sensor type 2 wires I2C operating at 3.3V with a precision of 2°C.
Read next to get details
piwan.org
PIWan project : Here is a new, quick & dirty project to be done with a raspberry PI : At work we currently have to simulate our application for a worldwide usage. We have really great tools for that but they need expertise and specific campaigns. The purpose of this document is to describe a RPI based solution with two Ethernet cards and some clever command lines to simulate a wan network for developers. The advantage of this solution will be to cost less than 100euros and will be easy to use with the right documentation.
See next pages for implementation details:
We all know that Internet of things is going to be the next revolution and it’s on the way, we also know that this revolution will not come from some main existing IT leaders as IBM, Microsoft, Amazon … ( I won’t say Google, because they are good player here) but from a lot of non existent companies/startups. It’s really interesting to see what is happening on crowd founding place like kickstarter (Ok, Amazon is part of it) these days : for sure we can see Internet of things in creation with a lots of connected gadget founded. But you can also found all the raw material used by the future companies to make this revolution real.
A year ago we had a lot of buzz around Raspberry PI ( and it continue to grow even if I think the reality of this environment is under its promise ) which is an interesting platform like BeagleBoard Black coming this month is. In my opinion these platforms are good to do geeky stuff but suffer of two issues : not natively wireless and consuming too much power. I assume Internet of thinks is mostly mobile and wireless : because I won’t put many cables in my house to connect these objects : I want wifi/battery stuff!