Hola me he decidido por fin por comprarme mi primer "juguete" en esto del mundo de la auditoria, con lo que queria empezar probando con una NHA...porq no.
Resulta que por lo visto se esta vendiendo una version mas reciente de esta tarjeta con chipset AR9271L comparado con el AR9271 que traia la anterior.
Este ultimo seria una version Low power consumption del AR9271 en un intento de volverle mas energeticamente eficiente peroooo....segun lo que entiendo del documento siguiente
el chipset quedaria limitado a 3.3V con un tx power de 300ma lo que le daria un poder de transmision de tan solo 17Dbm o sea de 50mw?
Tengo entendido que la primera version (la del AR9271 normal) ya proclamaba tener 630mw aunq en realidad se quedan en 400mw(27Dbm) reales .
Entonces tengo que deducir que las nuevas alphas nha ya no tienen las mismas prestaciones y se siguen vendiendo como si nada o como?
ni en la pagina de alpha ni en ningun sitio viene especificado este cambio.....
A ver si alguien con mas conocimiento me puede aclarar esto ...
An interesting discovery with these (thanks to bitmonkey) is that there is a low-power version of the AR9271 called the AR9271L. It trades off maximum transmit power (13dB - 17dB depending on bitrate) for lower power consumption. Given that the AR9271 consumes 0.68W when listening, any reduction would be welcome.
These modules could potentially connect directly to the pins that the USB connector on the MICRO uses, by first de-soldering the USB connector and making a short adapter cable/connector.
Using the AR9271L would be a little more involved as an additional 3.3V regulator would be required to supplement the 300mA maximum of the regulator on the MICRO. Specifically, the AR9271L can draw upto 500mA @ 3.3V according to the following datasheet. Frustratingly, the listen current of the AR9271L is not listed, only the max TX current draw.
This is AR9271L based, so we would still need a 500mA 3.3V regulator. There are plenty of 800mA 5v → 3.3V regulators out there.
The efficiency of these regulators is not ideal, however, as they are linear regulators, and thus increase the effective power consumption of the AR7291 Wi-Fi module to effectively be that of the AR9271 5V version. Basically they chop the 5V down to 3.3V and that 1.7V just goes out as heat. The end result is only 66% efficient, i.e., power consumption of the Wi-Fi module will effectively be 100/66 = 1.5x higher than it needs to be.
In that case, we might as well just use the AR7291 5V version, and get the extra Wi-Fi TX power, and reduce the complexity of the design a little.
Aqui os dejo la fuente:
http://developer.servalproject.org/dokuwiki/doku.php?id=content:meshextender:prototyping_on_olinuxino 
