Ok, three things: 1. there are daughterboards with temperature sensors; search for temperature in http://files.ettus.com/manual/page_dboards.html (I think it's tvrx2)
2. there are auxiliary ADCs. If you use a daughterboard that exposes these pins, you can use them with a PTC or something equivalent. 3. If your daughterboard exposes that (there are quite some that do), you can bit-band GPIO lines to talk to I2C temperature sensors. Greetings, Marcus On 12/02/2014 04:06 PM, khalid.el-darymli wrote: > Hi Marcus, > > Is there a temperature sensor on-board the N200 unit? If not, does it > support installing any such sensor? > > Thanks. > > Best regards, > Khalid > > > On Fri, Nov 28, 2014 at 5:44 PM, Marcus D. Leech <mle...@ripnet.com> wrote: > >> On 11/28/2014 03:41 PM, khalid.el-darymli wrote: >> >> >> >> Back to my original question, what should I do to correct for this? >> >> Thanks in advance. >> >> Best, >> Khalid >> >> >> Khalid: >> >> Thanks very much for the very-extensive data. My main concern, as one of >> the Ettus support team, was that there was something wrong with >> the hardware, but the magnitude of both the apparent phase and magnitude >> drift is entirely consistent with analog-hardware temperature >> effects, unrelated to clock stability, etc. >> >> Coax cables, for example, will change their loss characteristics and >> *effective length* with temperature, so with precise hardware like USRPs, >> it's >> easy to see these effects. >> >> FMCW radar isn't my area of expertise, so hopefully others can comment on >> RX-processing strategies to deal with this, as it *must* also be a problem >> with non-SDR FMCW radar implementations. >> >> >> >> >> >> >> On Fri, Nov 28, 2014 at 12:08 PM, <mle...@ripnet.com> wrote: >> >>> What is the magnitude of the frequency drift? >>> >>> What is the magnitude of the gain drift? >>> >>> What are you measuring backscatter *from*? >>> >>> >>> >>> >>> >>> >>> On 2014-11-28 10:14, khalid.el-darymli via USRP-users wrote: >>> >>> Hi, >>> >>> Given a set of synced *(i.e., using external GPS REF/PPS)*, >>> time-commanded and calibrated *(i.e., through compensating for the >>> phase/mag offset between digital Tx chirp prior to transmission and ADC'ed >>> Rx signals) *N200 devices with LFTX/LFRX daughterboards, that work with >>> coherent LFMCW chirps, I am still seeing a tiny drift (both in the >>> magnitude and frequency) of the calibrated back-scatter Rx chirp received >>> at time t1 when compared to an Rx chirp received at an earlier time t0. >>> >>> The more the N200 device runs (e.g., 5 hours), the greater the drift >>> is. Obviously, this drift is pertinent to both the DAC and ADCs and the GPS >>> referenced clocks of the N200 devices. >>> >>> My questions are: >>> >>> 1- Why I still see such drift although my devices are synced with an >>> external GPS? and how do I correct for it? >>> >>> 2- Can the *PLL Carrier Tracking *block in GRC be used to track and >>> correct for such a drift? If so, how do I set the max/min freq inputs for >>> this block? >>> >>> 3- Can *AGC2* or *AGC3 *block be useful in this regard? If so, are >>> there any examples to explain how the input parameters of these blocks can >>> be set up? >>> >>> >>> Thanks. >>> >>> Best regards, >>> Khalid >>> >>> >>> _______________________________________________ >>> USRP-users mailing >>> listUSRP-users@lists.ettus.comhttp://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>> >>> >> >> >> >> >> -- >> Marcus Leech >> Principal Investigator >> Shirleys Bay Radio Astronomy Consortiumhttp://www.sbrac.org >> >> > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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