Let’s start playing with sigfox technology

SigFox with TD1208I already wrote some stuff about Sigfox here, so may know that it is a really promising French technology IoT oriented. So I have a project to connect a Raspberry Pi and arduino system on a such peripheral.  The use of this technology is quite easy as it works like a modem, based on AT command transfered over a 9600bps serial line.  The main issue is that the chip is really CMS and hard to hack at home easily… by the way, as you see, a poor soldering makes it working for the test purpose.

As much as I have test, I can say that using this device to communicate with an Arduino or a PI is really easy ! code can be written in less than a minute ; compared to what you have to do to make wifi / Ethernet / GSM working in a stable way, this is incredibly easier ! You can also use the device as an autonomous sensor for temperature and contact switch of your choice for an affordable price.  In my point of view one thing is missing : you do not really know the signal quality and if you have a good connection or not with sigfox network. [update] The RSSI is indicated in the SigFox Api on the backend side for each of the received messages [/update] . Meaning you must receive the first one to know if the location is covered or not. This can be a problem to deliver a product and get an easy support to your consumer. The other limit of the technology, as much as I know is that you can transmit data but not receive some from the SigFox network [update] The ability for the device to receive messages will be soon added with limitation, but it will [/update]. In many case it is enough but sometime you like to respond to a specific value received. Read next to get details on how to use it …

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Use SPI port on raspberry PI

SPI is a frequent way to interface slave device with a micro-controller / cpu. SPI is a 4 wires synchronous connection between a slave and a master. As part of the 4 wires, there is a CLK signal, the speed is not defined and depends on the slave but it is usually > 10Mhz. SPI allows fast data transfer. Two data signals (MISO and MOSI) for Master (In/Out) Slave (In/Out) are used to transfer data in sync with the CLK clock. The last wire is a chip select signal named CEx for Chip Enable. As you can manage multiple slave, you have to manage different CEx signal, one per slave.

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Create a controlled 12V output for Raspberry Pi

I had to add a 12V controlled output for my raspberry Pi to connect a radio frequency system to my Pi. This system just need 12V to start transmitting but it needs 12V ! The raspberry can offer 5V or 3.3V. The solution is to use a currant elevator system. The one I built is based on a Texas Instrument component TPS6734, able to deliver 120mA / 12V with a 3.3V input.

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Getting start with rfrpi card v1.0 – rf433 for raspberry pi

rfrpi_2RfRpi card is a RF433 emitter and receiver add-on of Raspberry Pi. This card is based on high quality receiver and transmitter I have selected after tests you can find here and here. This article describes how to get start with this shield.

To buy this shield the best way is to sent me a comment on this post, the price is 60€

The Shield is now working with Raspberry PI B+ and previous versions. The Shield is also working with Raspberry PI 2+. For these two last version you need to compile a kernel driver.

 

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Eclipse IoT in Grenoble

Yesterday, I was in Grenoble for the Eclipse IoT days. It was a great opportunity to listen and learn from some actors of the IoT movement. The day was on the campus where we have been invited to see some student work on home automation and robotic for telepresence (see my twitter photo feed). The day was intensive on conferences with the really good quality and interest.

Most of the discussions / demonstrations were based on Home Automation, Smart house and globally telemetry. Not many industrial applications has been shown but some of the companies are working on industrial domain. Most of what has been shown is applicable on industry.

All the project are separating sensors, based on low cost / low energy devices associated to a local management/administration platform connected to Internet. The technology in use are mostly :

– RF and ZigBee for sensor to management platform

– Java for the management platform running the OSGi platform (Java) (this is also due to the fact Eclipse were organizing the conference and OSGi is Eclipse framework) This OSGi framework integrates management tools to connect / upgrade the platform remotely.

– Mqtt to communicate on Internet

– A custom MDM solution is deployed to manage the platforms (generally based on server management solution instead of MDM solutions) like roboconf.

Regarding the different architectures, some maintain the data on site with a in-house user interface, some export data outside on “cloud”  with an on-Internet user interface. As much as I’ve seen the in-house strategy is largely loosing on performance and interface quality due to the limited power of the management platform to perform advanced HTML experience. I assume this is also related to the Java choice to run these applications.

The other interesting learning is that most of the companies are using Raspberry Pi and Arduino to prototype solutions before, I assume, building a more robust platforms. Opensource is also mainly used and presented as the only solution to make the IoT market based on standard to be integrated all-together.

Control a high power circuit with arduino

irf9540I had to control power on an external circuit using an Arduino. the objective was to delay the power-on of a device consuming about 3A. One of the solution is to use a relay but it is a quite expensive solution another one is to use a Mosfet. This is the solution I’ll describe here.

 

 

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Raspberry PI RF433 transmitter shield

A lot of you are coming to my blog for RF433 with Raspberry PI content (here). This article is a small part of a larger project I have. As part of this project I built a Raspberry Pi shield including an RF433 emitter and receiver. I could sell this shield to some of view if it make interest to you. To make it I selected emitters and receivers to get the best quality / price compromise.  (read my other articles on this topic) I could sell it around 60€ + port.

Update : chek this article for all informations on the shield and buy it !

RF433 shield for Raspberry PI

RF433 shield for Raspberry PI v0.1

 

 

 

 

 

 

 

 

 

 

 

My question to you is : would you be interested in a such thing ?

If yes : leave me a comment with your email address ( I’ll will remove this address before validating it )

RF433 Raspberry PI shield v1.0

RF433 Raspberry PI shield v1.0

 

Here is the Version 1.0 with antenna connector integrated to PCB.