sal/: primitive USRP2-based spectrum analyzer
This commit is contained in:
Werner Almesberger
parent
ae3c89c68e
commit
e6f62bc71d
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sal: sal.cpp
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g++ -Wall -o sal sal.cpp \
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-lusrp2 -lfftw3 -lm `sdl-config --cflags --libs` -lSDL_gfx
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#include <stdint.h>
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#include <assert.h> /* sheer abuse */
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#include <math.h>
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#include <usrp2/usrp2.h>
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#include <usrp2/rx_nop_handler.h>
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#include <usrp2/copiers.h>
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#include <fftw3.h>
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#include "SDL.h"
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#include "SDL_gfxPrimitives.h"
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//#define N 1024
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#define XX 100
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#define N (1024*XX)
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#define AVG 1
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#define SCALE (2*XX)
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#define XRES (N/SCALE)
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#define YRES (768*XX/SCALE)
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#define DECIMATION 16
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static fftw_plan plan;
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static fftw_complex *in, *out;
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static double *w;
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static SDL_Surface *surf;
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#define SIZE (surf->h*surf->pitch)
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static int frames = 0;
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static int paws = 0;
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static int y_scale = 60;
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static uint32_t *bg = NULL;
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static long rate;
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static int snapshot = 0;
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static int avg_mode = 1;
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static void draw(const double *s)
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{
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int i, x, y, first, last;
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if (!bg)
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bg = (uint32_t *) calloc(SIZE, 1);
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if (paws)
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return;
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SDL_LockSurface(surf);
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memcpy(surf->pixels, bg, SIZE);
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for (y = y_scale; y < YRES; y += y_scale)
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hlineColor(surf, 0, XRES-1, y, 0x008040ff);
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uint32_t color = snapshot ? 0xff4000ff : 0xffffffff;
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last = YRES-1;
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for (i = 0; i != XRES; i++) {
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y = s[i]*y_scale;
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y = YRES-y+4*y_scale;
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if (y < 0)
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y = 0;
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if (y >= YRES)
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y = YRES-1;
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x = (i+XRES/2) % XRES;
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if (i)
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vlineColor(surf, x, last, y, color);
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if (!i)
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first = y;
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last = y;
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}
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vlineColor(surf, x+1, first, last, color);
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if (snapshot) {
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memcpy(bg, surf->pixels, SIZE);
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snapshot = 0;
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}
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SDL_UnlockSurface(surf);
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SDL_UpdateRect(surf, 0, 0, 0, 0);
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frames++;
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}
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static void collect(void)
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{
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static double sum[N];
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static int cnt = 0;
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int i, x, j;
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i = 0;
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for (x = 0; x != XRES; x++)
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for (j = 0; j != SCALE; j++) {
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double s = pow(out[i][0], 2)+pow(out[i][1], 2);
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if (avg_mode)
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sum[x] += s;
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else {
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if (sum[x] < s)
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sum[x] = s;
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}
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i++;
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}
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if (++cnt != AVG)
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return;
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cnt = 0;
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for (i = 0; i != XRES; i++)
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if (avg_mode)
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sum[i] = log(sum[i]/AVG/SCALE)/log(10);
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else
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sum[i] = log(sum[i])/log(10);
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draw(sum);
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memset(sum, 0, sizeof(sum));
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}
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class rx : public usrp2::rx_nop_handler
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{
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public:
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rx(uint64_t max_samples) : usrp2::rx_nop_handler(max_samples)
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{
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}
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bool operator()(const uint32_t *items, size_t nitems,
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const usrp2::rx_metadata *metadata);
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~rx(void)
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{
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}
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};
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bool rx::operator()(const uint32_t *items, size_t nitems,
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const usrp2::rx_metadata *metadata)
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{
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static std::complex<int16_t> host_items[N];
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static size_t have = 0, copy, over;
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bool ok;
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size_t i;
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ok = rx_nop_handler::operator()(items, nitems, metadata);
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copy = N-have;
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if (copy > nitems)
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copy = nitems;
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usrp2::copy_u2_16sc_to_host_16sc(copy, items, host_items+have);
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//fprintf(stderr, "nitems %u have %u copy %u\n", (unsigned) nitems, (unsigned) have, (unsigned) copy);
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have += copy;
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if (have == N) {
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for (i = 0; i != nitems; i++) {
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in[i][0] = host_items[i].real()*w[i];
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in[i][1] = host_items[i].imag()*w[i];
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}
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fftw_execute(plan);
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collect();
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have = 0;
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}
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over = nitems-copy;
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if (over)
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usrp2::copy_u2_16sc_to_host_16sc(over, items+copy,
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host_items+have);
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have += over;
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return ok;
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}
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static int key(SDLKey sym)
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{
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switch (sym) {
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case SDLK_a:
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avg_mode = 1;
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break;
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case SDLK_c:
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memset(bg, 0, SIZE);
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break;
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case SDLK_f:
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fprintf(stderr, "%d\n", frames);
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break;
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case SDLK_m:
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avg_mode = 0;
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break;
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case SDLK_p:
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paws = !paws;
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break;
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case SDLK_q:
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return 1;
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case SDLK_s:
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memset(bg, 0, SIZE);
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snapshot = 1;
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break;
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default:
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break;
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}
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return 0;
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}
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static void make_window(void)
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{
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int i;
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w = (double *) calloc(N, sizeof(double));
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for (i = 0; i != N; i++)
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// hamming
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w[i] = 0.54-0.46*cos(M_PI*2*i/(N-1));
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// hann w[i] = 0.5-0.5*cos(M_PI*2*i/(N-1));
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// blackman w[i] = 0.42-0.5*cos(2*M_PI*i/(N-1))+0.08*cos(4*M_PI*i/(N-1));
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}
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int main(void)
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{
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usrp2::usrp2::sptr u;
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usrp2::rx_nop_handler::sptr handler;
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usrp2::tune_result tr;
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handler = usrp2::rx_nop_handler::sptr(new rx(N));
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u = usrp2::usrp2::make("eth0", "");
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assert(u->stop_rx_streaming());
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assert(u->set_rx_gain(46));
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assert(u->set_rx_center_freq(2450000000ULL, &tr));
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assert(u->set_rx_decim(DECIMATION));
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// rate = u->adc_rate()/u->decim():
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// u->set_sample_rate(rate);
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u->adc_rate(&rate);
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in = (fftw_complex *) fftw_malloc(sizeof(fftw_complex)*N);
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out = (fftw_complex *) fftw_malloc(sizeof(fftw_complex)*N);
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plan = fftw_plan_dft_1d(N, in, out, FFTW_FORWARD, FFTW_ESTIMATE);
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make_window();
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if (SDL_Init(SDL_INIT_VIDEO) < 0) {
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fprintf(stderr, "SDL_init: %s\n", SDL_GetError());
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exit(1);
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}
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atexit(SDL_Quit);
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surf = SDL_SetVideoMode(XRES, YRES, 0, SDL_SWSURFACE);
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if (!surf) {
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fprintf(stderr, "SDL_SetVideoMode: %s\n", SDL_GetError());
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exit(1);
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}
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assert(u->start_rx_streaming(0));
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while (1||(!handler->has_errored_p() && !handler->has_finished_p())) {
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// while (!handler->has_finished_p()) {
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SDL_Event event;
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if (SDL_PollEvent(&event)) {
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if (event.type == SDL_KEYDOWN)
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if (key(event.key.keysym.sym))
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break;
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}
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assert(u->rx_samples(0, handler.get()));
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u->rx_samples(0, handler.get());
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}
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u->stop_rx_streaming(0);
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return 0;
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}
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