[YARDStick] questions

[Cinaed Simson]

Hi Mike - thanks for the info!

100 mW - awesome!

I like this one

 LED1: USB configured (should always be on)
 LED2: RX/TX active (currently the behavior of LED1)
 LED3: amplifier active

I was able to test TX using the scripts from Andrew Mohawk's blog.

I guess I'm going to have learn python.

-- Cinaed

On 03/21/2016 07:34 AM, Michael Ossmann wrote:
> Cinead,
> 
> Sorry your email was stuck waiting for moderation for a few days.  I
> meant for this list to be unmoderated, but I had the default setting
> wrong.  I fixed that today.
> 
> See my replies below.
> 
> On Sat, Mar 12, 2016 at 09:53:53PM -0800, Cinaed Simson wrote:
>>
>> Hi - when I plug my yardstick into the USB, no LEDs light up.
>>
>> When I receive a signal using rfcat, I see a green LED light up.
>>
>> When I transmit, no LEDs are lit.
>>
>> Is this normal?
> 
> Yes, that is normal behavior.  This is becoming a frequently asked
> question, so I started a FAQ:
> 
> https://github.com/greatscottgadgets/yardstick/wiki/Frequently-Asked-Questions
> 
> The best ways to check that the YS1 is powered on and operating on the
> USB port are lsusb, dmesg, or simply starting up rfcat and seeing if a
> dongle is detected.
> 
> We may want to change this behavior and configure one of the LEDs to
> always illuminate when the device is powered on, or perhaps it should
> turn on only after USB configuration is successful.  RfCat firmware
> originally assumed that there was only one LED on a dongle, but we have
> three on YS1.
> 
> What do people think about the following behavior?
> 
> LED1: USB configured (should always be on)
> LED2: RX active
> LED3: TX active
> 
> or this?
> 
> LED1: USB configured (should always be on)
> LED2: RX/TX active (currently the behavior of LED1)
> LED3: amplifier active
> 
> Or perhaps we should leave LED1 unchanged so it behaves the same as the
> LED on all other RfCat dongles.
> 
> By the way, the colors are:
> 
> LED1: green
> LED2: red
> LED3: yellow
> 
>> What is the maximum transmitting power of the yardstick in mW?
> 
> Roughly it is 100 mW (20 dBm).  The transmit power is reduced a bit as
> the frequency increases, and it may vary from unit to unit.  It is
> approximately 20 dBm at 300 MHz, 19 dBm at 450 MHz, and 18 dBm at 900
> MHz.  (Those numbers are with the TX amplifier enabled.)
> 
>> Is the RF gain 0 or maximum like the HackRF?
> 
> Yes, the RX and TX amplifiers (the ones not built into the CC1111) are
> either on or off.  Variable gain stages are available within the CC1111.
> 
>> How accurate is the frequency - does it drift?
> 
> The frequency stability of the crystal is specified at 20 ppm, so that
> is how much variability you can expect over the normal operating
> temperature range.
> 
> Mike
>