Teathimble_Firmware/msg.c

115 wiersze
2.4 KiB
C

/** \file msg.c
\brief Primitives for sending numbers over links.
*/
#include "msg.h"
/** write a single hex digit
\param v hex digit to write, higher nibble ignored
*/
void write_hex4(void (*writechar)(uint8_t), uint8_t v) {
v &= 0xF;
if (v < 10)
writechar('0' + v);
else
writechar('A' - 10 + v);
}
/** write a pair of hex digits
\param v byte to write. One byte gives two hex digits
*/
void write_hex8(void (*writechar)(uint8_t), uint8_t v) {
write_hex4(writechar, v >> 4);
write_hex4(writechar, v & 0x0F);
}
/** write four hex digits
\param v word to write
*/
void write_hex16(void (*writechar)(uint8_t), uint16_t v) {
write_hex8(writechar, v >> 8);
write_hex8(writechar, v & 0xFF);
}
/** write eight hex digits
\param v long word to write
*/
void write_hex32(void (*writechar)(uint8_t), uint32_t v) {
write_hex16(writechar, v >> 16);
write_hex16(writechar, v & 0xFFFF);
}
/// list of powers of ten, used for dividing down decimal numbers for sending, and also for our crude floating point algorithm
const uint32_t powers[] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000};
/** write decimal digits from a long unsigned int
\param v number to send
*/
void write_uint32(void (*writechar)(uint8_t), uint32_t v) {
uint8_t e, t;
for (e = 9; e > 0; e--) {
if (v >= powers[e])
break;
}
do
{
for (t = 0; v >= powers[e]; v -= powers[e], t++);
writechar(t + '0');
}
while (e--);
}
/** write decimal digits from a long signed int
\param v number to send
*/
void write_int32(void (*writechar)(uint8_t), int32_t v) {
if (v < 0) {
writechar('-');
v = -v;
}
write_uint32(writechar, v);
}
/** write decimal digits from a long unsigned int
\param v number to send
\param fp number of decimal places to the right of the decimal point
*/
void write_uint32_vf(void (*writechar)(uint8_t), uint32_t v, uint8_t fp) {
uint8_t e, t;
for (e = 9; e > 0; e--) {
if (v >= powers[e])
break;
}
if (e < fp)
e = fp;
do
{
for (t = 0; v >= powers[e]; v -= powers[e], t++);
writechar(t + '0');
if (e == fp)
writechar('.');
}
while (e--);
}
/** write decimal digits from a long signed int
\param v number to send
\param fp number of decimal places to the right of the decimal point
*/
void write_int32_vf(void (*writechar)(uint8_t), int32_t v, uint8_t fp) {
if (v < 0) {
writechar('-');
v = -v;
}
write_uint32_vf(writechar, v, fp);
}