utilities.cpp

00001 #include "lorawan_board.h"
00002 
00003 
00004 // Assumes 0 <= max <= RAND_MAX
00005 // Returns in the closed interval [0, max]
00006 long random_at_most(long max) {
00007     unsigned long
00008     // max <= RAND_MAX < ULONG_MAX, so this is okay.
00009     num_bins = (unsigned long) max + 1,
00010     num_rand = (unsigned long) RAND_MAX + 1,
00011     bin_size = num_rand / num_bins,
00012     defect   = num_rand % num_bins;
00013 
00014     long x;
00015     do {
00016         //x = random();
00017         x = rand();
00018     }
00019     // This is carefully written not to overflow
00020     while (num_rand - defect <= (unsigned long)x);
00021 
00022     // Truncated division is intentional
00023     return x/bin_size;
00024 }
00025 
00026 void memcpyr( uint8_t *dst, const uint8_t *src, uint16_t size )
00027 {
00028     dst = dst + ( size - 1 );
00029     while( size-- )
00030     {
00031         *dst-- = *src++;
00032     }
00033 }
00034 
00035 void
00036 #ifdef ENABLE_VT100
00037 print_buf(const uint8_t* const buf, uint8_t len, const char* txt, uint8_t row)
00038 {
00039     uint8_t i;
00040     vt.SetCursorPos(row, 1 );
00041     vt.printf("%s: ", txt);
00042     for (i = 0; i < len; i++)
00043         vt.printf("%02x ", buf[i]);
00044     vt.printf("\e[K");
00045 #else
00046 print_buf(const uint8_t* const buf, uint8_t len, const char* txt)
00047 {
00048     uint8_t i;
00049     pc.printf("%s: ", txt);
00050     for (i = 0; i < len; i++)
00051         pc.printf("%02x ", buf[i]);
00052     pc.printf("\r\n");
00053 #endif /* ENABLE_VT100 */
00054 }
00055 
00056 bool ValueInRange( int8_t value, int8_t min, int8_t max )
00057 {
00058     if( ( value >= min ) && ( value <= max ) )
00059     {
00060         return true;
00061     }
00062     return false;
00063 }
00064