From: drowe67 <drowe67@01035d8c-6547-0410-b346-abe4f91aad63>
Date: Fri, 28 Aug 2015 04:14:43 +0000 (+0000)
Subject: getting sensible plots from SFDR tests
X-Git-Url: http://git.whiteaudio.com/gitweb/?a=commitdiff_plain;h=dd73e1af41f236e4191f51f88a2450994b89f694;p=freetel-svn-tracking.git

getting sensible plots from SFDR tests

git-svn-id: https://svn.code.sf.net/p/freetel/code@2290 01035d8c-6547-0410-b346-abe4f91aad63
---

diff --git a/codec2-dev/octave/adc_sfdr_ut.m b/codec2-dev/octave/adc_sfdr_ut.m
new file mode 100644
index 00000000..c2363ed9
--- /dev/null
+++ b/codec2-dev/octave/adc_sfdr_ut.m
@@ -0,0 +1,28 @@
+% adc_sfdr_ut.m
+% David Rowe Aug 2015
+%
+% Processes data collected from STM32F4 or SFDR testing of ADC
+
+s = load_raw("~/stlink/adc.raw");
+Fs = 2E6;
+N = 1024;
+num_frames = length(s)/N;
+h = hanning(N);
+XdB = zeros(N/2,1);
+
+for i=1:num_frames
+  x = s((i-1)*N+1:i*N);
+  X = fft(x .* h);
+  XdB += 20*log10(abs(X(1:N/2)));
+end
+
+XdB /= num_frames;
+XdB -= max(XdB);
+
+figure(1)
+plot((0:N/2-1)*Fs/(1000*N), XdB)
+grid
+ylabel('Amplitude dB')
+xlabel('Frequency (kHz)');
+axis([0 Fs/(2*1000) -80 0])
+
diff --git a/codec2-dev/stm32/Makefile b/codec2-dev/stm32/Makefile
index 185cf412..ba9ceeb1 100644
--- a/codec2-dev/stm32/Makefile
+++ b/codec2-dev/stm32/Makefile
@@ -396,6 +396,7 @@ ADC_SFDR_UT_SRCS=\
 src/adc_sfdr_ut.c \
 gdb_stdio.c \
 ../src/fifo.c \
+src/iir_tuner.c \
 src/sm1000_leds_switches.c \
 src/debugblinky.c \
 src/system_stm32f4xx.c \
@@ -408,7 +409,7 @@ src/init.c \
 src/stm32f4_adc_tuner.o: src/stm32f4_adc_tuner.c
 	$(CC) $(CFLAGS) $^ -c -o $@ 
 
-adc_sfdr_ut.elf: $(TUNER_UT_SRCS) src/stm32f4_adc_tuner.o
+adc_sfdr_ut.elf: $(ADC_SFDR_UT_SRCS) src/stm32f4_adc_tuner.o
 	$(CC) $(CFLAGS) -O3 $^ -o $@ $(LIBPATHS) $(LIBS)
 	$(OBJCOPY) -O binary adc_sfdr_ut.elf adc_sfdr_ut.bin
 
diff --git a/codec2-dev/stm32/src/adc_sfdr_ut.c b/codec2-dev/stm32/src/adc_sfdr_ut.c
index c8c8cdf3..2b3a1165 100644
--- a/codec2-dev/stm32/src/adc_sfdr_ut.c
+++ b/codec2-dev/stm32/src/adc_sfdr_ut.c
@@ -41,33 +41,41 @@
 #include "../src/codec2_fm.h"
 #include "stm32f4xx.h"
 
-#define REC_TIME_SECS 1
+#define BUFS          10
 #define FS            2E6
-#define N             (ADC_TUNER_BUF_SZ/2)
+#define N             1024
 
 extern int adc_overflow1;
 
 int main(void) {
-    short  buf[N];
-    int    bufs, i;
-    FILE  *fadc;
-
-    ftuner = fopen("adc.raw", "wb");
-    if (ftuner == NULL) {
+    unsigned short unsigned_buf[N];
+    short          buf[N];
+    int            sam;
+    int            i, j, fifo_sz;
+    FILE          *fadc;
+
+    fadc = fopen("adc.raw", "wb");
+    if (fadc == NULL) {
         printf("Error opening output file: adc.raw\n\nTerminating....\n");
         exit(1);
     }
-    bufs = FS*REC_TIME_SECS/N;
-    fifo_sz = ADC_TUNER_N;
-    printf("Starting! bufs: %d %d\n", bufs, fifo_sz);
+    fifo_sz = ADC_TUNER_BUF_SZ;
+    printf("Starting! bufs: %d %d\n", BUFS, fifo_sz);
  
     adc_open(fifo_sz);
     adc_set_tuner_en(0); /* dump raw samples, no tuner */
 
     sm1000_leds_switches_init();
 
-    for (i=0; i<bufs; i++) {
-        while(adc1_read(buf, N) == -1);
+    for (i=0; i<BUFS; i++) {
+        while(adc1_read((short*)unsigned_buf, N) == -1);
+
+        /* convert to signed */
+
+        for(j=0; j<N; j++) {
+            sam = (int)unsigned_buf[j] - 32768;
+            buf[j] = sam;
+        }
 
         /* most of the time will be spent here */
 
@@ -77,6 +85,6 @@ int main(void) {
     }
     fclose(fadc);
 
-    printf("Finsihed!\n");
+    printf("Finished!\n");
 }