Read_aux_adc

GNU Radio
1

hi all,

I want to use the read_aux_adc method to get the RSSI, but the results I
got
seem meaningless.

  1. Everytime I call the read_aux_adc, the result increases step by step.
  2. No matter whether there is a sender, the result is the same.

Does anyone come up against this problem ?
Any suggestion is helpful to me.

Thanks

P.S. the result is
3232
3136
3152
3176
3192
3204
3200
3208
3220
3232
3244
3252
3264
3272
3280
3288
3292
3296
3304
3308
3316
3320
3324
3328
3324
3336
3332
3336
3340
3340
3344
3348
3352
3356
3356
3360
3364
3364
3368
3368
3372
3376
3376
3376
3380
3380
3380
3384
3384
3388
3388
3388
3392
3392
3392
3396
3396
3400
3400
3400
3400
3404
3404
3404
3404
3408
3408
3408
3408
3412

2

On Mon, May 31, 2010 at 11:00:17AM +0800, jf w wrote:

hi all,

I want to use the read_aux_adc method to get the RSSI, but the results I got
seem meaningless.

  1. Everytime I call the read_aux_adc, the result increases step by step.
  2. No matter whether there is a sender, the result is the same.

Does anyone come up against this problem ?
Any suggestion is helpful to me.

What daughterboard are you using?
Which side is it installed in, side A or side B?
What argument values are you passing to read_aux_adc?
Are you calling it from C++ or Python?

Eric

3

I’m using RFX2400 daughterboard on side B, my arguments are slot=2
which_adc = 0 ,and I’m calling it from python.

Your question inspire me that my arguments may be wrong. I think the
slot
argument should be 3(SLOT_RX_B), but I don’t know the meaning of
which_adc
and how to set it.

There are two aux_adc on one ad9862:aux_adc_a and aux_adc_b , but there
are
four pins : aux_adc_a1,aux_adc_a2, aux_adc_b1 and aux_adc_b2. But what
is
the input of the signal on these pins?

Thanks a lot.

2010/5/31 Eric B. [email protected]

4

On Mon, May 31, 2010 at 04:42:47PM +0800, jf w wrote:

Thanks a lot.

/*!

  • \brief Read auxiliary analog to digital converter.
  • \param which_side [0,1] which d’board
  • \param which_adc [0,1]
  • \returns value in the range [0,4095] if successful, else
    READ_FAILED.
    */
    virtual int read_aux_adc (int which_side, int which_adc) = 0;

Try

v = u.read_aux_adc(1, 0)

I think the RSSI is on adc 0, but not 100% sure.

Eric

5

Thanks for you reply, After reading the code, I think the argument 1,0
should be right.
But the result is strange. when there isn’t a sender , the value
returned is
always 12. While there is a sender and the distance between sender and
receiver is less than 1m, the value returned is between 0~24 (maybe less
than 12), no matter what the tx-amplitude of sender is. Does the result
make
sense?

Thanks a lot.

P.S.
the result with a sender:
4 24 8 20 24 16 20 20 20 8 8 20 16 20 20 16 4 12 24 0 20 24 8 20 0 8
12 16 0 16 4;

the result without a sender:
12 12 12 12 12 12 12 12 12 12 12 12 12 12

2010/6/1 Eric B. [email protected]