diff options
Diffstat (limited to 'CAN-binder/libs/nanopb/examples/using_double_on_avr')
8 files changed, 0 insertions, 327 deletions
diff --git a/CAN-binder/libs/nanopb/examples/using_double_on_avr/Makefile b/CAN-binder/libs/nanopb/examples/using_double_on_avr/Makefile deleted file mode 100644 index 874a64b..0000000 --- a/CAN-binder/libs/nanopb/examples/using_double_on_avr/Makefile +++ /dev/null @@ -1,24 +0,0 @@ -# Include the nanopb provided Makefile rules -include ../../extra/nanopb.mk - -# Compiler flags to enable all warnings & debug info -CFLAGS = -Wall -Werror -g -O0 -CFLAGS += -I$(NANOPB_DIR) - -all: run_tests - -.SUFFIXES: - -clean: - rm -f test_conversions encode_double decode_double doubleproto.pb.c doubleproto.pb.h - -test_conversions: test_conversions.c double_conversion.c - $(CC) $(CFLAGS) -o $@ $^ - -%: %.c double_conversion.c doubleproto.pb.c - $(CC) $(CFLAGS) -o $@ $^ $(NANOPB_CORE) - -run_tests: test_conversions encode_double decode_double - ./test_conversions - ./encode_double | ./decode_double - diff --git a/CAN-binder/libs/nanopb/examples/using_double_on_avr/README.txt b/CAN-binder/libs/nanopb/examples/using_double_on_avr/README.txt deleted file mode 100644 index d9fcdfc..0000000 --- a/CAN-binder/libs/nanopb/examples/using_double_on_avr/README.txt +++ /dev/null @@ -1,25 +0,0 @@ -Nanopb example "using_double_on_avr" -==================================== - -Some processors/compilers, such as AVR-GCC, do not support the double -datatype. Instead, they have sizeof(double) == 4. Because protocol -binary format uses the double encoding directly, this causes trouble -if the protocol in .proto requires double fields. - -This directory contains a solution to this problem. It uses uint64_t -to store the raw wire values, because its size is correct on all -platforms. The file double_conversion.c provides functions that -convert these values to/from floats, without relying on compiler -support. - -To use this method, you need to make some modifications to your code: - -1) Change all 'double' fields into 'fixed64' in the .proto. - -2) Whenever writing to a 'double' field, use float_to_double(). - -3) Whenever reading a 'double' field, use double_to_float(). - -The conversion routines are as accurate as the float datatype can -be. Furthermore, they should handle all special values (NaN, inf, denormalized -numbers) correctly. There are testcases in test_conversions.c. diff --git a/CAN-binder/libs/nanopb/examples/using_double_on_avr/decode_double.c b/CAN-binder/libs/nanopb/examples/using_double_on_avr/decode_double.c deleted file mode 100644 index 5802eca..0000000 --- a/CAN-binder/libs/nanopb/examples/using_double_on_avr/decode_double.c +++ /dev/null @@ -1,33 +0,0 @@ -/* Decodes a double value into a float variable. - * Used to read double values with AVR code, which doesn't support double directly. - */ - -#include <stdio.h> -#include <pb_decode.h> -#include "double_conversion.h" -#include "doubleproto.pb.h" - -int main() -{ - uint8_t buffer[32]; - size_t count = fread(buffer, 1, sizeof(buffer), stdin); - pb_istream_t stream = pb_istream_from_buffer(buffer, count); - - AVRDoubleMessage message; - pb_decode(&stream, AVRDoubleMessage_fields, &message); - - float v1 = double_to_float(message.field1); - float v2 = double_to_float(message.field2); - - printf("Values: %f %f\n", v1, v2); - - if (v1 == 1234.5678f && - v2 == 0.00001f) - { - return 0; - } - else - { - return 1; - } -} diff --git a/CAN-binder/libs/nanopb/examples/using_double_on_avr/double_conversion.c b/CAN-binder/libs/nanopb/examples/using_double_on_avr/double_conversion.c deleted file mode 100644 index cf79b9a..0000000 --- a/CAN-binder/libs/nanopb/examples/using_double_on_avr/double_conversion.c +++ /dev/null @@ -1,123 +0,0 @@ -/* Conversion routines for platforms that do not support 'double' directly. */ - -#include "double_conversion.h" -#include <math.h> - -typedef union { - float f; - uint32_t i; -} conversion_t; - -/* Note: IEE 754 standard specifies float formats as follows: - * Single precision: sign, 8-bit exp, 23-bit frac. - * Double precision: sign, 11-bit exp, 52-bit frac. - */ - -uint64_t float_to_double(float value) -{ - conversion_t in; - in.f = value; - uint8_t sign; - int16_t exponent; - uint64_t mantissa; - - /* Decompose input value */ - sign = (in.i >> 31) & 1; - exponent = ((in.i >> 23) & 0xFF) - 127; - mantissa = in.i & 0x7FFFFF; - - if (exponent == 128) - { - /* Special value (NaN etc.) */ - exponent = 1024; - } - else if (exponent == -127) - { - if (!mantissa) - { - /* Zero */ - exponent = -1023; - } - else - { - /* Denormalized */ - mantissa <<= 1; - while (!(mantissa & 0x800000)) - { - mantissa <<= 1; - exponent--; - } - mantissa &= 0x7FFFFF; - } - } - - /* Combine fields */ - mantissa <<= 29; - mantissa |= (uint64_t)(exponent + 1023) << 52; - mantissa |= (uint64_t)sign << 63; - - return mantissa; -} - -float double_to_float(uint64_t value) -{ - uint8_t sign; - int16_t exponent; - uint32_t mantissa; - conversion_t out; - - /* Decompose input value */ - sign = (value >> 63) & 1; - exponent = ((value >> 52) & 0x7FF) - 1023; - mantissa = (value >> 28) & 0xFFFFFF; /* Highest 24 bits */ - - /* Figure if value is in range representable by floats. */ - if (exponent == 1024) - { - /* Special value */ - exponent = 128; - } - else if (exponent > 127) - { - /* Too large */ - if (sign) - return -INFINITY; - else - return INFINITY; - } - else if (exponent < -150) - { - /* Too small */ - if (sign) - return -0.0f; - else - return 0.0f; - } - else if (exponent < -126) - { - /* Denormalized */ - mantissa |= 0x1000000; - mantissa >>= (-126 - exponent); - exponent = -127; - } - - /* Round off mantissa */ - mantissa = (mantissa + 1) >> 1; - - /* Check if mantissa went over 2.0 */ - if (mantissa & 0x800000) - { - exponent += 1; - mantissa &= 0x7FFFFF; - mantissa >>= 1; - } - - /* Combine fields */ - out.i = mantissa; - out.i |= (uint32_t)(exponent + 127) << 23; - out.i |= (uint32_t)sign << 31; - - return out.f; -} - - diff --git a/CAN-binder/libs/nanopb/examples/using_double_on_avr/double_conversion.h b/CAN-binder/libs/nanopb/examples/using_double_on_avr/double_conversion.h deleted file mode 100644 index 62b6a8a..0000000 --- a/CAN-binder/libs/nanopb/examples/using_double_on_avr/double_conversion.h +++ /dev/null @@ -1,26 +0,0 @@ -/* AVR-GCC does not have real double datatype. Instead its double - * is equal to float, i.e. 32 bit value. If you need to communicate - * with other systems that use double in their .proto files, you - * need to do some conversion. - * - * These functions use bitwise operations to mangle floats into doubles - * and then store them in uint64_t datatype. - */ - -#ifndef DOUBLE_CONVERSION -#define DOUBLE_CONVERSION - -#include <stdint.h> - -/* Convert native 4-byte float into a 8-byte double. */ -extern uint64_t float_to_double(float value); - -/* Convert 8-byte double into native 4-byte float. - * Values are rounded to nearest, 0.5 away from zero. - * Overflowing values are converted to Inf or -Inf. - */ -extern float double_to_float(uint64_t value); - - -#endif - diff --git a/CAN-binder/libs/nanopb/examples/using_double_on_avr/doubleproto.proto b/CAN-binder/libs/nanopb/examples/using_double_on_avr/doubleproto.proto deleted file mode 100644 index 72d3f9c..0000000 --- a/CAN-binder/libs/nanopb/examples/using_double_on_avr/doubleproto.proto +++ /dev/null @@ -1,15 +0,0 @@ -// A message containing doubles, as used by other applications. -syntax = "proto2"; - -message DoubleMessage { - required double field1 = 1; - required double field2 = 2; -} - -// A message containing doubles, but redefined using uint64_t. -// For use in AVR code. -message AVRDoubleMessage { - required fixed64 field1 = 1; - required fixed64 field2 = 2; -} - diff --git a/CAN-binder/libs/nanopb/examples/using_double_on_avr/encode_double.c b/CAN-binder/libs/nanopb/examples/using_double_on_avr/encode_double.c deleted file mode 100644 index cd532d4..0000000 --- a/CAN-binder/libs/nanopb/examples/using_double_on_avr/encode_double.c +++ /dev/null @@ -1,25 +0,0 @@ -/* Encodes a float value into a double on the wire. - * Used to emit doubles from AVR code, which doesn't support double directly. - */ - -#include <stdio.h> -#include <pb_encode.h> -#include "double_conversion.h" -#include "doubleproto.pb.h" - -int main() -{ - AVRDoubleMessage message = { - float_to_double(1234.5678f), - float_to_double(0.00001f) - }; - - uint8_t buffer[32]; - pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer)); - - pb_encode(&stream, AVRDoubleMessage_fields, &message); - fwrite(buffer, 1, stream.bytes_written, stdout); - - return 0; -} - diff --git a/CAN-binder/libs/nanopb/examples/using_double_on_avr/test_conversions.c b/CAN-binder/libs/nanopb/examples/using_double_on_avr/test_conversions.c deleted file mode 100644 index 22620a6..0000000 --- a/CAN-binder/libs/nanopb/examples/using_double_on_avr/test_conversions.c +++ /dev/null @@ -1,56 +0,0 @@ -#include "double_conversion.h" -#include <math.h> -#include <stdio.h> - -static const double testvalues[] = { - 0.0, -0.0, 0.1, -0.1, - M_PI, -M_PI, 123456.789, -123456.789, - INFINITY, -INFINITY, NAN, INFINITY - INFINITY, - 1e38, -1e38, 1e39, -1e39, - 1e-38, -1e-38, 1e-39, -1e-39, - 3.14159e-37,-3.14159e-37, 3.14159e-43, -3.14159e-43, - 1e-60, -1e-60, 1e-45, -1e-45, - 0.99999999999999, -0.99999999999999, 127.999999999999, -127.999999999999 -}; - -#define TESTVALUES_COUNT (sizeof(testvalues)/sizeof(testvalues[0])) - -int main() -{ - int status = 0; - int i; - for (i = 0; i < TESTVALUES_COUNT; i++) - { - double orig = testvalues[i]; - float expected_float = (float)orig; - double expected_double = (double)expected_float; - - float got_float = double_to_float(*(uint64_t*)&orig); - uint64_t got_double = float_to_double(got_float); - - uint32_t e1 = *(uint32_t*)&expected_float; - uint32_t g1 = *(uint32_t*)&got_float; - uint64_t e2 = *(uint64_t*)&expected_double; - uint64_t g2 = got_double; - - if (g1 != e1) - { - printf("%3d double_to_float fail: %08x != %08x\n", i, g1, e1); - status = 1; - } - - if (g2 != e2) - { - printf("%3d float_to_double fail: %016llx != %016llx\n", i, - (unsigned long long)g2, - (unsigned long long)e2); - status = 1; - } - } - - return status; -} - - - - |