Archive for the “1.TECNOLOGÍAS (teórico)” Category

Nowadays it seems to be clear what PoE is and the advantages that it brings. PoE (Power over Ethernet) means that you can get a power supply through Ethernet cables. It facilitates the installation of multiple electronic systems that have an Ethernet connection, like an interface. This technology is standardized through the IEEE 802.3af and IEEE802.3at and nowadays we can find electronic devices and equipment where the manufacturer has chosen to assemble a SilverTel module.  These modules are easy to integrate as they only require a minimal amount of external components, they meet safety regulations and most importantly these days, they are low cost.

This week I heard that  SilverTel had a few new modules that can get a power supply of up to 100W through a CAT5/6 Ethernet cable for HDBaseT technology.

What is HDBaseT?

The first thing to know is that the major electronic manufacturers like LG, Samsung, Sony and Valens have formed an alliance. The idea is to promote and commercialize the HDBaseT name. This allows you to eliminate multiple cables and connections in the home and office in exchange for one CAT5/6 cable. With this one cable we can connect computers, TVs, games consoles, multimedia players etc. as you are guaranteed a 10.2 Gbps bandwidth.


I don’t understand the advantages that it offers. 

For example: Suppose you have a 1080 Full HD multimedia hard disk and the television is 100m away, how do you connect them? With a CAT5e cable both devices can be HDBaseT enabled.

But there isn’t a plug where I want to install the TV… 

You don’t need to find a plug for the TV which is 100m away from the multimedia player if we use PowerOverBaseT technology, called POH.


I don’t think that the TV is powered with this. 

Now the consumption of a 40” LED TV is around 70W, Energy Star Consortium 6.0’s intention is that all screen dimensions and LCD/LED televisions don’t reach 85W.

Great… and above all energy savings. Explain a little more what is POH exactly? 

Based on POH technology, the idea is to get data and power supply from the same CAT5/6 cable up to a maximum distance of 100m. Just like in PoE, we have devices that inject power supply, PSE and the device that is supplied with PD (in our example, the TV).

And… can’t I use PoE? I already have it working with home and office phones, do I have to get rid of PoE access points? 

No don’t throw anything away as it is compatible. If you connect a PoE telephone to the POH network, the PSE injector will recognize it and it will give it less voltage/current in order to meet the specifications, this means that you won’t need to throw away any existing devices.

Do you recognize it? How? 

When connecting a PoE or PoH device, before adding the PSE power source, power it with a couple of volts so that there is communication between them and so that the device has an internal electronic signature to show that is PoE-PoH enabled. If valid, the injector will then apply the power. If not, it’s obvious that it’s not a PoE-PoH device and no voltage is applied.

Ok. I am a manufacturer and I want to include PoH in my products. What electronics do I need? Where do I start? 

Let’s not complicate matters. The company SilverTel has a lot of experience with PSE injector modules and PoE, PoE+ and PoE Ultra extractors. It has just released some new modules (Ag6600 and Ag5600) which are compatible with the standard PoH for HDBaseT. They have been preparing for PoH for 7 years. With these modules you won’t need to meet the standard, with a minimal amount of components your electronics will be ready.

It seems like this is directed towards television manufacturers… 

No it’s not. There are other applications where PoH has great potential and high power is needed. Some examples are: sound amplifiers (sometimes built into the speaker), point of sale terminals with screens, signage applications and display panels. It is also used to ensure that there is a CC power supply when it is essential.

I hope you liked it. It’s an interesting article written by my colleague Jesus Santos. Thank you.  ;)

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Today we are going to speak about GPS, or rather GNSS. A few days ago a very explanatory document fell into my hands, made by my colleague Jesús Santos, as a result of a new product launched by the company Fastrax which many of you know. I think that it could be quite interesting for a lot of you, especially those of you who are dedicated to the issue of positioning. So I included it in the article.

What is GNSS?

GNSS stands for Global Navigation Satellite System. “GNSS modules” are satellite receivers whatever brand they are or whatever country they come from. What happens is that we use the word GPS receivers for everything related to positioning. It’s suitable but this American system is not the only one that exists, there are many others:

Russian GLONASS system
Chinese Beiuou-2/Compass
Japanese QZSS
Indian Gagan

And we are waiting for the European Galileo system expected in 2014…

Fastrax has a GNSS module. The IT6000 is based on an ST chipset. The great thing about this GPS module is that it works with the American GPS system as well as the Russian GLONASS system simultaneously.

Some would think…would this benefit me?

The answer is that the receiver will work in the most extreme conditions. Imagine a street with tall buildings (what we call the urban canyon). The receiver will not only be able to see the few GPS satellites, but it will also be able use the GLONASS satellites.

Let’s look at an example. Pay attention to the following chart. GPS satellites are light blue. GLONASS satellites are dark blue. There you have the IT600 module working with 22 satellites simultaneously.


To make it clearer, here it is on a map. Here you have a test drive in Dallas. In yellow you have GPS only module traces, the “best” working all the time with 4-6 satellites. In blue you have the same route working with an IT600 module and with 8-12 satellites simultaneously (as many GPS as GLONASS). The result? Amazing, the picture says it all.


Can I make use of the same antenna that I use with my GPS module now with the IT600?

Not really. The GPS and GLONASS frequencies differ slightly. For these GNSS receivers to work well, you need an antenna that is ready to receive the 2 signals. Do these antennas exist? Yes, they do.

That’s very interesting. What other stand out features does this module have?

It has a many but here are a few:

  • The IT600 module can be assisted (AGPS) which is what we know as Autonomous AGPS or predictive AGPS. The first one is the most interesting. We can simply say that it collects the ephemerides, it works out a 5 day prediction of them and stores then in an SQI flash memory (fast bus) which is inside. For the other possibility you need the classic AGPS server in order to collect them periodically using GPRS/HSPA.
  • DR support (Odometro/Gyro or CAN DWP).
  • So what is this?
  • Dead reckoning. Receiver’s capacity to continue giving its position without satellite visibility thanks to external sensors (nearly always Gyro and Odometer). Note that this feature is not implemented yet.
  • CAN. CAN bus.
  • DWP: Differential Wheel Pulse info. (something like the odometer)
  • I2C  for MEMS sensors

Most important of all are the sensors that we can connect to the IT600. An accelerometer gives an idea of the acceleration that the module undergoes. There has to be a change in the speed for it to work. An e-compass or magnetometer measures the earth’s magnetic field, like a compass. That’s what it really is, an electronic compass that helps the accelerometer to find the way at low speeds or if it has stopped. Many mobiles and PDAs incorporate the compass to help positioning. Sensor summary: speed (odometer o even DWP), acceleration (accelerometer), turns (gyroscope) and magnetometer (electronic compass).

These sensors are put close together in the I2C bus carrying the IT600 and it will use and it will get information by itself from the same UART serial port. Furthermore, it can be connected to the vehicle’s CAN bus.


Wow this module has some mind-blowing features…

Well there’s more. It’s a programmable device; you can make your own application and embed it inside. This means that the module is used as a microprocessor as it has an ARM946 processor with programmable GPIOs, 3 UART, SPI, I2C, CAN, 2ADC… a 208MHz micro with 8MB flash memory capacity and 128KB of SRAM.

I hope that it has been interesting talking about GNSS for those who did not know of any other systems. I’ll take this opportunity to wish you all a Merry Christmas and a Happy New Year for 2012 (and of course, good luck with the Christmas lottery tomorrow) what a pipe dream… ;)


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Today we are going to touch on and dig out some old, published articles here on from several months ago, nearly two years ago. Do you remember this article from the end of 2009?

In this article, I talked about the imminent appearance of the new EU3 Cinterion module highlighting that one of its greatest strengths was that it supported the new 900MHz UMTS band that was approaching. The following is worth remembering from this article:

“From a technical point of view it’s better because it offers a greater coverage and penetration than the current UMTS2100, which is ideal for rural coverage and even coverage in cities where the greater the ability to penetrate, the better the coverage in buildings.

It’s obvious from an economic point of view.  One reason is that in order to have a greater scope to cover a specific area, you need to install less base stations with UMTS900 than UMTS2100. Another reason is that the current GSM stations are still valid and they only require small, inexpensive adaptations unlike the UMT2100.

I only have one more tip for those of you who are going to start a new project today with GSM/GPRS modules and who are looking into the future and who are evaluating modules from different manufacturers. The tip is that you read the announcement in the news about the new EU3 module published on Cinterion’s website. Pay special attention to this title, “Cinterion Announces First UMTS Module to Support Seamless 3G Transition for Existing GPRS/EDGE Designs”.


A little later in the article from May 2010:

We talked about everything more deeply on a technical level with the 3G 900MHz (it is recommended reading). One thing to note from this article, as many people asked and will ask this question, is that both in the text as well as in reader’s comments is the clarification that current GSM/GPRS technology (at 900MHz) will coexist with the new 900MHz UMTS.

Finally 10 months ago I posted an article on the EU3 module’s TCP/IP stack:

Note the last paragraph where it says:

“Finally here is a detail worth noting. The same B2B connector and (nearly) the same pinout as in the TC63i have been used with the EU3 Cinterion module. Therefore, whoever is designing a board to use with the TC63i, I recommend you to take a look at an application note called EU3_e-migration (which is part of the EU3 documentation) as it shows small differences to consider when moving from the TC63i to the EU3. Or rather, this document allows us to design a board in a way that we can use the TC63i or EU3 interchangeably, with obvious advantages that we can use in the future. If some of you are undecided whether to use a MC55i or a TC63i with a new design (I see this happen often), you should consider the compatibility with the EU3. At least it helped me to decide.”

Those who betted on the new EU3 Cinterion module or made a design with a TC63i and considered the application notes to make a compatible circuit like we talked about here, they can start to reap the benefits from the 9th of September (because it’s an implementation process that will last a couple of years). :)

Here you have more information of the implementation of the new 900MHz UMTS:

Well, I hope that this article has been interesting for some of you and satisfying for others who have made the right choice. I will now continue working on the new version of the MTXTunnel v6.0 manual which will be out soon. :)



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For those who are looking for new development ideas to ride out these difficult times here I come with something interesting. Today I am going to talk a little bit about something that you probably haven’t heard of: Bluetooth Low Energy.

We all know what Bluetooth is I would dare to say that all of you have used it as it comes with any mobile phone with a medium-low frequency range. You already know that we can create data connections (like using the SPP profile), audio connections and much more with Bluetooth. But with regards to consumption, Bluetooth has always been limited and this also limits certain applications. Lots of people turn Bluetooth off on their mobiles if they aren’t using it as it drains the battery quickly. You can imagine that it’s not feasible Bluetooth connectivity modules with battery powered devices.

So recently a new standard has appeared called BLE (Bluetooth Low Energy). This new Bluetooth (which from my point of view only has the name and nothing else) is designed for low power applications, which is suggested by its name. To date no mobiles have this technology but in coming months we will see if new mobiles with Bluetooth Low Energy technology are going to appear.

But will a Bluetooth Low Energy device be compatible with a standard Bluetooth device?
Well, no. What happens is the telephones will be dual. They will set up a standard Bluetooth module as usual but with a Bluetooth Low Energy module. The standard Bluetooth can be turned off like in any terminal but the Bluetooth Low Energy cannot. ;)


Bluetooth Low Energy is designed to efficiently transmit small quantities of information at low speeds. If we compare the consumptions of the standard Bluetooth and Bluetooth Low Energy, we see that it’s 15 times more efficient. In order to achieve this efficiency, 3 basic concepts of how it works have been optimized:

1.-Connection modes and discovery

With a standard Bluetooth module, a device that wants to receive a connection or is in visible mode should enable its receiver for long periods of time so that it’s awake and waiting to receive a packet if someone wants to communicate with it. This means there is at least 22ms of activity, so 32 different frequencies should be scanned and it should take a significant amount of time checking each one before moving onto another.

On the other hand, with Bluetooth Low Energy, when a device wants to receive a connection it only needs to send 3 small packets (on broadcast) and then it will quickly receive a connection or data if there is another device that wants to communicate with it. It only takes 1.4ms, about 17 times less than with normal Bluetooth.

Furthermore, you can include application data in these broadcast packets. This is very important because it means that with Bluetooth Low Energy we will be able to use broadcast in our applications without establishing a connection. You can imagine the amount of applications (door opening applications by proximity etc.)

2.- The number of packets transmitted during the connection.

With Bluetooth Low Energy, when you want to establish a connection all of the connection information is contained in a packet which is transmitted from the master to the slave. This information includes the FHSS map and other settings. This means that no additional negotiations are needed in order to begin sending useful data once the link has been established, which means less time which in turn means less consumption.

Also, when communicating between two devices with traditional Bluetooth, you lose time with packet synchronization and lag time, even though neither of the devices have anything to transmit. With Bluetooth Low Energy, the data packets have 1 bit of “more data” that indicates whether the sending device has packets to send or not and therefore if you need to keep your device “talking” or not.

Another very important feature is ACK packets. You send an ACK (a package without data, just to show that a packet has been received successfully) with normal Bluetooth for each packet sent. With Bluetooth Low Energy empty ACK data packets are only sent when it is really necessary. That way you don’t unnecessarily waste time and energy.

3.- The size of each packet.

The size of the data packet’s headers has decreased. The size of a standard Bluetooth header was made so that it could be sent in 210 us whereas with Bluetooth Low Energy is sent in 112 us (nearly half).

I’m interested, how can I work with a Bluetooth Low Energy module?

Well Bluegiga (distributed in Spain by Matrix) has just brought some Bluetooth Low Energy modules onto the market, specifically the BLE112 and BLED112 models.
Here’s a datasheet for you to look at. I will talk about them more thoroughly when my development kit arrives. As they are so new I still haven’t had the chance to have a SDK and play with them, hopefully I will soon.

I will only talk about the most important thing. Unlike other types of Bluegiga modules, these no longer use an internal CSR chip. They use a Texas Instruments chip, specifically the cc2540. Furthermore the module has an 8051-based processor (with 8Kb of RAM and 128Kb of FLASH) to embed user applications, so you don’t need to use it if you don’t want an external micro. It has 2 UART ports or SPI that we can connect directly to sensors, screens, digital and analog inputs/outputs, watchdog timer, hw AES128 encryption etc.  It’s a low-cost and complete module. As I said, I will talk about these modules when I have an SDK and have done a reliable test.



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If you make applications with GPRS modems, a lot of the time you will encounter the problem that IP addresses, which are assigned by the network operator, are dynamic.

What’s a dynamic IP? It means that every time one of your modems connects to the GPRS network, the operator will give it a different IP address.

For a lot of applications it won’t matter. For example if I have a modem that collects data from a datalogger and the modem sends the data to a central server via GPRS at the end of the day, it doesn’t matter if the modem’s IP address is dynamic. So in this case it’s the modem that makes the connection to the central server (which must have a fixed IP address or a DNS at least).



The problem arrives when we want to work with GPRS modems in server mode i.e. with modems that are permanently connected to GPRS and are listening to a specific TCP port waiting for incoming connections (typical remote maintenance). In this situation you need to know the modem’s IP address. There are various solutions to resolve this problem. I will talk about one of them today – DynDns service.

With DynDns you can assign a specific IP address to a DNS for free. To do this, you just have to open an account

Let’s look at a concrete example.

I’m not going to give you an example with Java instead we are going to look at it with AT commands. Doing it with Java (from the following) is practically that same as using the ATCommand class.

Imagine that we have created our own account in with the following data:

DNS server:
Login: mylogin
Password: myPassword
Current IP: 80,100,101,102 (the IP assigned by the operator)

What I want to achieve with the modem is that the address points to the IP address (which was assigned by my operator at a given time). This means that if do a ping from my PC to it will have the same response if I do a ping to

Which AT commands are required to make point to the IP 

Well to configure the GPRS connection profile (with Movistar) use the following:


To configure the http service profile use the following (note that for DynDns you need to use basic authentication protocol with login and password, therefore we turn on hcAuth):


Finally we keep the socket open to initiate the HTTP connection:

^SIS: 0, 0, 2201, “HTTP/1.1 401 Unauthorized”
^SIS: 0, 0, 2200, “HTTP Redirect
^SIS: 0, 0, 2201, “HTTP/1.1 200 OK”
^SISR: 0, 1
Este último evento ^SISR: 0,1 indica que han llegado datos al socket “0″ y tenemos que leerlos con AT^SISR:
^SISR: 0, 17


By only doing this, we have associated the DNS to the IP for free and without having to pay a monthly fee to the operator. If I remember correctly they charge around 12 Euros + VAT for each fixed IP address. This is something that we will later incorporate into MTXTunnel, although possibly we may only do it in the advanced version.

Well, I hope that this post has been interesting for you and useful for your Siemens / Cinterion GPRS modem applications, as you can see you can do everything with them they are marvellous. ;)

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Today I am going to talk about a little Multiplex feature in Siemens modems. As you know, some of the current modems like the MTX65+G  (GPRS+GPS modem) and the imminent MTX-HC25+PLUS (UMTS+GPS) have a single communication serial port.

There may be some applications where we’d like to have more than one serial port.

Why would I want more than one serial port?

Well for example it could be to maintain a GPRS communication through a serial port, to monitor the coverage level through another serial port and to obtain GPS coordinates through the other serial port. So yes it is possible but we use Multiplex mode for this.

The Multiplex protocol (GSM 07.10 y 3G TS 27.010) enables an asynchronous serial interface to be split into three virtual channels. It’s basically a communications protocol that encapsulates communications between the host (e.g. PC/ microprocessor) and a corresponding device (modem) with three virtual serial ports.

How do you use it?

Siemens provides some drivers for Windows (XP/2000) to be able to use this feature. If you don’t want to use a PC with Windows and you want to use a microprocessor for example, you can install the Multiplex protocol. It’s quite complex but it can be done.

To use driver in Windows, all you have to do is install the Siemens WinMux application. When you run it a window like this will appear:

Driver Multiplex All you have to do is have the modem physically connected to the PC’s COM port so that the driver will find it by clicking on the “Start Scan” button. Once the modem is connected it will suggest some port numbers as to where you should install the 3 virtual serial ports. As you can see in the figure above, I have installed it in COM24, COM25 and COM26.

After installing the driver, go to Start-> Control Panel-> System-> Hardware-> Device Manager:

Driver Multiplex  You will se that the “Serial Multiplex Driver” has been assigned to a COM, in my case COM1. If you right click on the installed driver’s properties you will be able to change the assigned COM, the speed and the virtual COM numbers.

One last thing, there’s a catch with the number assigned to each of the COM ports (it’s probably Windows’ fault) and the catch is that it doesn’t let you install it on any COM number. For example there are programs which don’t accept high COM numbers (COM24/COM25/COM26). If you want to change it, I have already registered to Windows you already know:

Start -> Run -> Manage

I searched for a VirtPort1 string and I changed the assigned COM for another one that interested me. It worked without any problems although I had to restart the computer after making a change before using it.


If we no try to open up to 3 HyperTerminal windows, each one associated with a virtual COM port, and we send AT commands you will see that it works without any problems.

I hope you found this interesting, see you next time. ;)  

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