Category Archives: Technology

Tips and test on technological product and components. Operating system, networks, hardware, security…
Astuces et tests autour de produits et composants technologiques, systèmes, réseaux, hardware, sécurité …

NRF 51 BLE library for custom services

Posted on by
3
nrf51 ble stack

nrf51 ble stack

After building my first project using an nRF51 device from the template given in the SDK I was really disappointed by the result, I mean, it works but the code is really bad and hard to maintain.

The given examples are not really generic and if you have to create your custom ble service and characteristics you have  to make many modification in a code that is not clean for all.

So my second project was to create a ble library to make creation of custom services & characteristics as easy as possible and to create a main file with less code.

Continue reading →

Play with remote selfie shutter and make your own Amazon dash button

Posted on by
3
Bluetooth remote shutter

Bluetooth remote shutter

Remote Selfie shutter are really low cost Bluetooth 3 buttons that are really easy to hack for making different applications.

These button can be found on ebay, amazon or aliexpress like following this link for less that 6$. The button is paired to the smartphone and then allow to execute photo shoot without the need of any third party application.

 

 

Continue reading →

RF433 – Raspberry PI GPIO kernel driver for interrupt management

Posted on by
13

You may have read some of my post about RF433 and Raspberry PI. Basically with RPI 1, I was using wiringPi interrupt handler to manage the RF433 decoding. The problem is that with RPI2 and RPI B+ the delay to take an interrupt that was becomes unpredictable. And the timing constraints are not respected. As a consequence part of the messages are loss because for these delay.

One of the solution (the software one) is to be more efficient to proceed the interrupts and the way to do this is to compile a kernel driver for directly handling the interrupts. This is what this post is about. This comes to complete the RFRPI code and associated hardware. A complete source code and software for using it is on the rfrpi bitbucket repository.

Challenge of the coming days : write a kernel driver to manage interruption quicker on a raspberry pi 2. I’m happy to find a lot of example on Internet and in particular this one, that is really looking like what I’m trying to do. This post is describing all the step needed to do this.

Continue reading →

Let’s graph the Internet of Things

Posted on by
2

plot-IoTIoT is generating data and to quicky look at it during the prototype phase is sounds good to plot these data in a dashboard. There are many solution you can install on your server and configure to get pretty nice dashboard. But if you want to go faster it would be really nice to have a SaaS solution for doing this. I have tested some of the solution I have found and friends helped me to found (not easy to search on google …). This post details these experiments

Continue reading →

Extend TD1204 Standard firmware to simplify GPS

Posted on by
Reply
TD1204 / Sigfox & GPS

TD1204 / Sigfox & GPS

The TD1204 modem firmware is a easy to use solution for sending message to Sigfox network. It starts to be complex when you want to create your own message including the GPS position. The standard firmware returns the satellite NMEA frames in text mode and you have to process it.

To make it simple I built a modification of the standard modem firmware to add an extra command to enrich a message with a GPS coordinate automatically.

 

Continue reading →

First step in LoRa land – microchip RN2483 test

Posted on by
73
Microchip RN2483 Lora

Microchip RN2483 Lora

After spending some time reading and writing about LoRa it was a good time to make some real test of this technology.

As actually there is no network for LoRa, as much as I know, in my town, I expected to start a simple LoRa test (point to point and not as part of a WAN). I just bought some RN2483 LoRa module from Microchip online and also get some from Avnet (thank you Guillaume)

 

The module is easy to solder on a prototype board and get its command over a serial port. I choose to make two modules :

  • The first one is connected to a FTDI cable and will stay at home as a basestation
  • The second one is connected to an Arduino and will be a mobile device for my test

Continue reading →

What is LoRa ?

Posted on by
Reply

Lora-300x171LoRa is a dedicated network for Internet Of Things and Machine2Machine communications. It is actually the main competitor against SigFox.

As LoRa is actually rising in France with different announce from 2 of the main cellular operators deploying the network, it is a good time to have a post on what it is, how it works and what differs compared with SigFox.

Continue reading →

Silabs EFM8 a low cost microcontroller based on 8051 core

Posted on by
Reply
EFM8 chip

EFM8 chip

If you my blog and the lesson section you may notice my interest for 80×51 micro-controller family. Silicon Labs has recently launch a new 8b family based on this core.

With price less than 1 euros, they are interesting candidates for low cost hacking and hardware design. Even the programming cable is not really expensive ( $35 + port + Tax ) and the development environment is free.

EFM8 provides a 50MHz core with all the usual I/O – Serial, I2C, SPI. Plus 12 bit ADC, voltage regulator, oscillator…

Continue reading →