Here's electronic world

Overview Of RFM12 Wireless module

2011-06-16T06:48:00.000-07:00

Making wireless devices always is complicated if you want to have your own receiver/transmitter circuit design...working on ISM-band tranceiver circuits needs to have experiences of high frequency courses obviously not simple as low frequency communication circuits...
a good cheap solution is working with RF modules...HopeRF is a chinese company has produced cheap SPI-based RF modules for general purposes first time...
first products of hoperf was RFM01 (receiver) and RFM02 (transmiter) FSK modules called as half-duplex devices,main problem was demo program released first time in their datasheets...that still is presented for some projects...finally i decided to switch to RFM12 later full-duplex tranceiver module and could work with it both through AVR and PIC wether in Basic or C language...
i will place a working project in C language (for codevision) in next post...RFM12 is interfaced with avr in the project to send temprature read from a LM35 sensor...
for the begining have the pinout image:

AMD is comming with new CPUs & GPUs (A-series)

2011-06-15T12:37:00.000-07:00

competition between AMD and Intel again !
The new A-series of AMD is used in three lines of processors, all being a combination of AMD, CPU and a Radeon GPU on a single circuit. The A4-3300M and A4-3310MX are low-end dual-core chips clocked at 1.9GHz and 2.1GHz respectively, equipped with a Radeon HD6480G clocked at 444MHz. Their main competition will be the cheapest Intel i3 chips. The quad-core mid-range A6-3400M and A6-3410MX contain 1.4GHz and 1.6GHz CPUs respectively, and a Radeon 6520G as a GPU. Finally, the quad-core high-end A8 line is aimed at enthusiast HD and 3D environments, and aspires to compete with Intel i7 chips. The A8 is clocked at up to 1.9GHz and equipped with Radeon HD6620G graphics.
HD entertainment capability and and DirectX 11-enabled graphics, along with 10.5 hours of battery life, are features of the new chips. The A-series chips are built on a 32-nanometer process technology and are the only Sandy Bridge rival on the market. Until now, there have only been low-end C- and E-series AMD processors from the Fusion family, with E-350 being the most notable, featured in a number of netbooks .
The AMD Fusion platform supports HDMI 1.4a, DisplayPort 1.1, and USB 3.0. According to AMD's own figures, A-series chips beat Intel's Sandy Bridge in terms of graphics performance, although it's probably fair to judge after the arrival of the first APU devices.
watch video here about APU:

better technique for measuring blood pressure (ultrasonic)

2011-06-15T06:58:00.000-07:00

Italian medical imaging company Esaote, the TU/e researchers started their experiments using plastic tubes, worked their way up to carotid arteries from pigs, and are now performing trials on human subjects.

Using the new technique, blood pressure can be non-invasively measured at any point in the body. The skin in the area is first covered in gel, to maintain a good contact, and then the ultrasound scanner is applied. Utilizing sophisticated signal processing techniques, the system is able to visualize the blood flow and the blood vessel wall motion. By plugging that data into a mathematical model, the blood pressure at that exact location can be derived.

The technology allows users to observe variations in blood pressure and flow, in time with the beating of the heart, which will provide information on what's going on "downstream" from that location.

Google Goggles and Search by Image and Voice

2011-06-15T06:32:00.000-07:00

Hmmm...google is still by far the most popular search engine on the Web, at Google's 'Inside Search' event, the company has announced several new features designed to ensure it stays on top of the lucrative search engine game. Users will now be able to search using images, enter search terms by voice and have the top search results pre-rendered so they appear instantly.

Google Goggles is letting users conduct searches based on pictures taken on mobile devices since 2009 and now Search by Image brings the same functionality to the desktop. Users can drag and drop an image from the Web or stored locally on their computer over the Google search box and Google will try and identify it and bring up relevant results. Users can also Search by Image by copying and pasting an image URL or uploading an image by clicking on the camera icon in the search box. Google is also releasing extensions for Chrome and Firefox browsers that will let users search an image on the web by right-clicking on it.
Goggles
Voicesearch

Nokia AT commands

2011-06-15T06:22:00.000-07:00

Well,let's goinig on with the previous post,
Nowadays,AT commands is usual way to connect to a cell phone using serial protocols...don't need any software exept hyper terminal...
here's a PDF for AT commands of Nokia cell phones:
ATNOKIA.PDF

here's a basic circuit you can connect a uC to F-bus using At commands to connect with...

Nokia F-bus and AVR

2011-06-15T06:02:00.000-07:00

After many projects about sending SMS via AVR using GSM modems, i decided to interface my old nokia mobile supporting F-bus to AVR...for the begining you should know F-bus so well to go on with that project...

here's a basic introduction for f-bus V2:

Protocol principle
This protocol is a packet based protocol with a control transmission mecanism. Each
packet as a sequence number.
Protocol exchange layout
Here is a sample of the protocol exchange :
1. P.C send a packet
2. Phone send a Ack packet
3. Phone Send the answer packet
4. P.C send a ack packet

Why this protocol has a Control Transmission mecanism ? Because you could have a collision
du to the nature of the cable. For the same reason the Acknoledgement sequence
number is here to know which packet have been received.
Protocol Speed
To properly con gure the com port i has to be like this :
speed 115 200
num bits 8
parity none
Stop bit 1

Standard message definition
A standard message look like this one :
1E 02 00 04 00 0B 01080002010463020401 40 00 3900
which corespond to :
[Frame type(1)][Src dev(1)][Dst dev(1)][CMD(1)][Frame type(1)][Len(1)][DATA(X)][Seq(1)][Padd(1 or 0)][Chksum(2)]
Frame type
The frame type indicate which type of protocol is using :
{ 1E : Serial Fbus frame
{ 1c : Irda Fbus frame
Src dev and Dst dev
Indicate the source and the destination device
{ 02 Phone
{ 00 Computer
CMD
This the command type, it de ne which type of information is about.
{ need a x
Frame type
Used if the message exceeded 255 then it give which part is sending. (need to be more
detailled)

Len
The len of the packet. To calculate it : Data + Sequence number so in other word : len
= data + 1 (in hex)
Data
the packets data.
Seq : Sequence number for regular packet
the sequence number for the standard frame seem's to be between 40 up to 47 So always
initialize it to 40 at the beginning seem's to be working
Padd
Since the packet as to be a odd number, if the len is even it as to be added. The padd
is always 00.
Chksum
The check sum is in fact two dierent checksum. The rst hex represente the Xor of all
the odd hex block from the packet, the second represent the Xor of all the even Hex block
of the packet.
Ack message defnition
A standard message look like this one :
1E 00 02 7F 00 02 02 01 1E 7C
which corespond to :
[Frame type(1)][Src dev(1)][Dst dev(1)][CMD(1)][Frame type(1)][Len(1)][DATA(X)][Seq(1)][Chksum(2)]
Ack message defnition
A standard message look like this one :

click below :