IoT disruption, why it is the appropriate time ?

In a previous post I explained why the IoT is appearing in this period thanks to the network technology evolution. It would not be a complete analysis if I would not care about the social evolution. In parallel of IoT and technologies there are other rising trends : Makers, Fablabs, embedded systems, 3d printing and crowd-founding.

Take a look at personal computing some decades ago when guys like Jobs or Gates make the first line of code and solder the first micro-processors in their garage ; they just used the technological elements available that time and were able to make them doing much more than what they have been made for. They did it because they were able to do it. The same story appends in the late 90’s with Internet : anyone was able to code some PHP stuff and create a service in his garage thanks to this students have created Facebook and many more.

At the opposite, when smart phone appeared in the middle of the 90’s it was a technology that requires strong industrial assets and this technology has been limited to major companies. The smart-phone revolution had been the same opening door to programmer to an new area with applications (apps). In fact all previous hardware evolutions since the Personal Computer beginning was requiring huge technological assets to be part of it.

IoT disruption is breaking these last 40 years where only software were hackable by getting hardware accessible.

Let see why

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IoT, M2M, quick panorama on main technologies

rfrpi_3This year M2M and IoT are two of the most heard keywords in our technological domain. One of these is fresh new, I mean a couple of year old, when the other one is pretty much older. M2M, standing for Machine to Machine is a capability for two machines (or more) to discuss together and take actions. Like a temperature sensor allowing your boiler to decide when to start or stop. In the industry where automatism are in place since many year, M2M is something in place, running, not new. IoT, standing for Internet of Things is part of the M2M technology but actually raising. In IoT the main word is Internet and it stands for the capability of an object to talk over Internet on its own. Why only now ? mostly because now it starts to be possible.

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Design a raspberry Pi HAT shield

Raspberry PI Shiel Hat standard

Raspberry PI Shiel Hat standard

When you want to design a shield for Raspberry Pi, you have to follow the HAT standard. This standards describes the form factor of the shield to ensure future compatibility. It also describes the configuration solution for the board based on a flash containing necessary information. The Hat standard link gives all the detailed specification to design a such shield. In this post I’ll describe my experience of designing such shield and you will find the basic elements I build and now sharing with you.

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I2C activation on raspberry PI B+ and 2

The new version of kernel now activate the device-tree standard, it means that instead of having all module activated by default with some stopped by a blacklist system, now, all are disable and activated only when described in a device tree.

Device tree details the system architecture and dependencies following configuration files. The device tree can be owned by the shield itself in an attached eprom.

As a consequence, now, i2c / spi are not activated by default. So if you need to activate it on startup. For this, edit /boot/config.txt and add line at the end like :

dtparam=i2c_arm=on   # for i2c 1
dtparam=i2c_vc=on    # for i2c 0
dtparam=spi=on
dtparam=i2s=on

dtparam=i2c_arm=on,i2c_vc=on

Then reboot

Add wifi to an arduino for 4€ with an ESP8266

esp8266 wifi for arduino

esp8266 wifi for arduino

The ESP8266 is a simple standalone addon for any board that works fine with Arduino and only cost less than 4€ on ebay.

It can operate as a device or an AP can gives wireless network connectivity to your application. It is interfaced with Arduino based on a serial line. The only problem of a such thing ( as for most of wifi chip ) is the power consumption. It requires about 150mA to run ; a lot for batteries.

My Friend @couac made a really good post on how to make it working with a Yabas, basically any Arduino board, I recommand the reading of his post : william post on ESP8266

Sigfox Rf test first experience

This morning, some colleagues helped me to test the rf performance of one of my sigfox tracker. I’m really not an RF expert, I try to improve but there still be a long way to go…

In this design I’m using a TD1204 and a Wurth smd 868 antenna ; I have a 100 ohm impedance net between both (sure it is bad) and LC circuit (that sound not to be the good one – btw).

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Design a 50 ohm impedance microstrip line for RF signals

For RF signal you must draw a 50 ohm net between chip and antenna to get the best performance.This post is the result of my web research on this topic …

There are two ways to design your emitter to antenna solution:

  • A microstrip line : basically you have a net on the top driving the signal and a ground plane on the PCB bottom

microstrip line

  • A coplanar wave guide : your signal is drive by a PCB net on top with two ground plane area on its left & right. If you also have a ground plane on the bottom it’s a grounded coplanar wave guide

The way to get a 50 ohm communication way is different depending on your choice.

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Tobeca 3d printing settings for PLA

After some month of use of the Tobeca printer and a lot of time spent to find the right settings, this post is summarizing my experience. I mostly worked with PLA because I was not really fan of using acetone and abs+ acetone mix on a 80°C heating plate, so I’ll not yet detail how to setup ABS, but why not later. So this post is about PLA, about temperature, about adherence and Repetier settings.

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