WIP DSSS decoding

2 files changed, 51 insertions, 7 deletions

diff --git a/controller/fw/tools/butter_filter_gen.py b/controller/fw/tools/butter_filter_gen.py
new file mode 100644
index 0000000..059dea0
--- /dev/null
+++ b/controller/fw/tools/butter_filter_gen.py
@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+
+import sys
+import contextlib
+
+import scipy.signal as sig
+
+
+@contextlib.contextmanager
+def wrap(left='{', right='}', file=None, end=''):
+    print(left, file=file, end=end)
+    yield
+    print(right, file=file, end=end)
+
+@contextlib.contextmanager
+def print_include_guards(macro_name):
+    print(f'#ifndef {macro_name}')
+    print(f'#define {macro_name}')
+    yield
+    print(f'#endif /* {macro_name} */')
+
+macro_float = lambda f: f'{f}'.replace('.', 'F').replace('-', 'N').replace('+', 'P')
+
+
+if __name__ == '__main__':
+    import argparse
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-m', '--macro-name', default='butter_filter', help='Prefix for output macro names')
+    parser.add_argument('fc', type=float, help='Corner frequency [Hz]')
+    parser.add_argument('fs', type=float, help='Sampling rate [Hz]')
+    parser.add_argument('n', type=int, nargs='?', default=6, help='Filter order')
+    args = parser.parse_args()
+    
+    sos = sig.butter(args.n, args.fc, fs=args.fs, output='sos')
+
+    print('/* THIS IS A GENERATED FILE. DO NOT EDIT! */')
+    with print_include_guards(f'__BUTTER_FILTER_GENERATED_{args.n}_{macro_float(args.fc)}_{macro_float(args.fs)}__'):
+        print(f'#define {args.macro_name.upper()}_ORDER {args.n}')
+        print(f'#define {args.macro_name.upper()}_CLEN {(args.n+1)//2}')
+        print(f'#define {args.macro_name.upper()}_COEFF ', end='')
+        for sec in sos:
+            with wrap():
+                print('.b=', end='')
+                with wrap():
+                    print(', '.join(f'{v}' for v in sec[:3]), end='')
+                print(', .a=', end='')
+                with wrap():
+                    print(', '.join(f'{v}' for v in sec[4:6]), end='')
+            print(', ', end='')
+        print()
diff --git a/controller/fw/tools/gold_code_header_gen.py b/controller/fw/tools/gold_code_header_gen.py
index 8247457..fa98fce 100644
--- a/controller/fw/tools/gold_code_header_gen.py
+++ b/controller/fw/tools/gold_code_header_gen.py
@@ -58,19 +58,13 @@ if __name__ == '__main__':
         print(f' *')
         print(f' * Each code is packed left-aligned into {nbytes} bytes in big-endian byte order.')
         print(f' */')
-        print(f'const uint8_t gold_code_{args.n}bit[{2**args.n+1}][{nbytes}] = {{')
+        print(f'const uint8_t {args.variable}[{2**args.n+1}][{nbytes}] = {{')
         for i, code in enumerate(gold(args.n)):
             par = '{' + ' '.join(f'0x{d:02x},' for d in np.packbits(code)) + f'}}, /* {i: 3d} "{"".join(str(x) for x in code)}" */'
             print(textwrap.fill(par, initial_indent=' '*4, subsequent_indent=' '*4, width=120))
         print('};')
         print()
-        print(f'const uint8_t * const {args.variable} __attribute__((weak)) = (uint8_t *const)gold_code_{args.n}bit;')
-        print(f'const size_t {args.variable}_nbits __attribute__((weak)) = {args.n};')
     else:
         print('/* THIS IS A GENERATED FILE. DO NOT EDIT! */')
         with print_include_guards(f'__GOLD_CODE_GENERATED_HEADER_{args.n}__'):
-            print(f'extern const uint8_t gold_code_{args.n}bit[{2**args.n+1}][{nbytes}];')
-
-        with print_include_guards(f'__GOLD_CODE_GENERATED_HEADER_GLOBAL_SYM_{args.variable.upper()}__'):
             print(f'extern const uint8_t {args.variable}[{2**args.n+1}][{nbytes}];')
-            print(f'extern const size_t {args.variable}_nbits;')