libwr2rf: never cross 360 when updating iq dac phase

507f927e · Tristan Gingold · 21c010ec · 507f927e
Commit 507f927e authored Sep 01, 2021 by Tristan Gingold
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Showing with 10 additions and 26 deletions

board.c software/libwr2rf/board.c +10 -26

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--- a/software/libwr2rf/board.c
+++ b/software/libwr2rf/board.c
@@ -223,9 +223,9 @@ int libwr2rf_dac_set_phase_amp(struct libwr2rf_dev *dev, unsigned ch,
                               float amplitude, float phase, unsigned verbose)
 {
  if (!(amplitude >= 0.0 && amplitude <= 1.0))
-    return -1;
-  if (!(phase >= 0.0 && phase <= 360.0))
-    return -1;
+    return LIBWR2RF_ERROR_BAD_PARAM;
+  if (!(phase >= -360.0 && phase <= 360.0))
+    return LIBWR2RF_ERROR_BAD_PARAM;

  float phase_rad = phase * M_PI / 180.0;
  float igainf = amplitude * cosf (phase_rad);
@@ -235,7 +235,7 @@ int libwr2rf_dac_set_phase_amp(struct libwr2rf_dev *dev, unsigned ch,
  int qgain = dac_convert(qgainf);

  if (!dac_check_range(igain) || !dac_check_range(qgain))
-    return -1;
+    return LIBWR2RF_ERROR_BAD_PARAM;

  if (verbose)
    fprintf(stderr,
@@ -284,20 +284,13 @@ int libwr2rf_dac_phase_amp_ext(struct libwr2rf_dev *dev, unsigned ch,
                               float amplitude, float phase, unsigned verbose)
 {
  const int phase_step = 15;
-  int iphase;
+  int iphase = (int)phase;
  unsigned phase_addr;
  int last_phase;
  int res;

-  /* According to fmod:
-       the returned value has the same sign as x and a magnitude
-       less than the magnitude of y.  */
-  phase = fmodf(phase, 360.0);
-  if (phase < 0.0)
-    phase += 360.0;
-
-  /* IPHASE is in 0 .. 360.  */
-  iphase = (int)phase;
+  if (!(phase >= -360.0 && phase <= 360.0))
+    return LIBWR2RF_ERROR_BAD_PARAM;

  /* Current phase.  */
  switch (ch) {
@@ -311,29 +304,20 @@ int libwr2rf_dac_phase_amp_ext(struct libwr2rf_dev *dev, unsigned ch,
      return LIBWR2RF_ERROR_BAD_ID;
    }

-  last_phase = libwr2rf_read16(dev, phase_addr);
+  last_phase = (short)libwr2rf_read16(dev, phase_addr);

  while (1) {
    int dph = iphase - last_phase;
-    if ((dph >= 0 && dph <= phase_step)
-        || (dph < 0 && dph >= -phase_step)
-        || (dph >= 0 && dph >= 360 - phase_step)
-        || (dph <= 0 && dph <= -360 + phase_step)) {
+    if (dph >= -phase_step && dph <= phase_step) {
      /* Smooth enough, apply directly.  */
      return libwr2rf_dac_set_phase_amp(dev, ch, amplitude, phase, verbose);
    }

-    if ((dph >= 0 && dph <= 180) || (dph < 0 && dph < -180))
+    if (dph >= 0)
      last_phase += phase_step;
    else
      last_phase -= phase_step;

-    /* Normalize the phase. */
-    if (last_phase < 0)
-        last_phase += 360;
-    else if (last_phase >= 360)
-        last_phase -= 360;
-
    res = libwr2rf_dac_set_phase_amp(dev, ch, amplitude, last_phase, verbose);
    if (res != 0)
      return res;