On Mon, Apr 03, 2006 at 06:34:24AM -0700, Angilberto Muniz Sb wrote: > Folks, > Is it possible to read/write from/to the low speed > ADC/DAC from Python?
The python interfaces to the usrp are specified in gr-usrp/src/usrp1.py. Check usrp/host/lib/usrp_basic.h for the missing documentation (sorry about that. We've got a situation that's violating the "write once" rule): //! magic value used on alternate register read interfaces static const int READ_FAILED = -99999; /*! * \brief Write auxiliary digital to analog converter. * * \param which_dboard [0,1] which d'board * N.B., SLOT_TX_A and SLOT_RX_A share the same AUX DAC's. * SLOT_TX_B and SLOT_RX_B share the same AUX DAC's. * \param which_dac [2,3] TX slots must use only 2 and 3. * \param value [0,4095] * \returns true iff successful */ bool write_aux_dac (int which_board, int which_dac, int value); /*! * \brief Read auxiliary analog to digital converter. * * \param which_dboard [0,1] which d'board * \param which_adc [0,1] * \returns value in the range [0,4095] if successful, else READ_FAILED. */ int read_aux_adc (int which_dboard, int which_adc); So from python: d_board = 0 # 0: side A, 1: side B v = u.read_aux_adc(d_board, 0) ok = write_aux_dac(d_board, 2, 2048) Be sure to pay attention to the comments above that start with N.B. You may also want to take a look at the usrp schematics if this isn't clear. > If possible, what would be a safe rate ? It's pretty slow. You'll need to try it to see how fast it'll run on your system. Each read or write is a round trip across the USB, plus bit banging the SPI bus to talk to the AD9862. There's no clock pacing the reads and writes of the the aux dac/adc's, so the samples won't be evenly spaced. Most daughterboards that use them, use them for things like setting an analog gain control, or reading back an RSSI indication. Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
