I had a go at building a signal generator on Pothos a couple of days with some limited success. I just want to generate a simple sine wave at 750 MHz - has anybody got any Pothos / Gnu radio / Limesuite files for doing this?
The alternative is to use an ADF4351 documented here:
This .ini should give you sine wave at 750MHz from TX_1_2 output. Just botched the config, canāt guarantee anything, as I donāt have tools to check it right now. Further gain and calibration adjustments should be done.
To use the Arduino Due the little orange PCB is required to convert 0.05" pitch JTAG connectors to 0.1" pitch for ease of use. Trying to botch this up is not recommended! Thereās also special code to upload to the FPGA for enabling external SPI, which is very straight forwards:
There are multiple ways to achieve the same effect.
In my case, Tx carrier wave is set to 730MHz and TxTSP is set to generate test signal(sine wave) at 1/4th Tx sampling rate, which is (160MHz CGEN)/(2 IQ channels)/4=20MHz
Doing frequency hopping this way is not correct, as this could only work for extremely small changes. If you change (0x011D or 0x011E) too much, PLL can lose lock and would need retuning.
To change center frequency reliably you need to write correct values to these registers:
0x011C[10], 0x011D, 0x011E, 0x011F[8:6], 0x0121[10:1]
Or use NCO to upconvert/downconvert your signal. Itās possible to have 16 frequency offests configured in 0x0241:0x0261 registers, and switch between them using 0x0240[4:1] bits.
If we used lime as signal generator whats the lowest and highest frequency we can used it for and what kind signal we can used like āsquare,triangle,noise etcā
Yes I expect that the information is in there somewhere but rather like looking for a needle in a haystack. Somebody at lime Microsystems should know what the formula is without too much bother. Maybe @andrewback might know who the best person to ask is?
Hereās the procedure used to set all those registers SetFrequencySX , you should see the relationships there.
only the 0x0121[10:1] canāt be calculated exactly, so it needs to be searched dynamically using this procedure TuneVCO
@ricardas
Thank you for the post.
i am trying to open on limesuite using āTxSine750M.iniā given in the post on Ubuntu 18.04 but unfortunately iām having the following errors that i have attached. my platform is VMWare running ubuntu 18.04 with host operating system as windows 10.