Mercurial > public > ostc4
view ostc4pack/src/checksum_final_add_fletcher.cpp @ 335:c11ce8c885d3 PressureMeasure_Improvment
Use average calculation for pressure: precondition was that pressure values jittered +- 10 HPa from one capture (once a second) to the other. Basically pressure is measured several times a second => using these values in an additional history calculation reduces the jitter down to +-1 per second
Additionaly a similar function has been added to the surface pressure capture to further reduce the jitter in long therm measurements (once a minute)
author | ideenmodellierer |
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date | Tue, 13 Aug 2019 21:46:26 +0200 |
parents | 1e707b34667e |
children | 01f40cb1057e |
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#include <iostream> #include <stdlib.h> #include <stdio.h> #include <string.h> #include <time.h> void fletcher16(unsigned char *result1, unsigned char *result2, unsigned char const *data, size_t bytes ) { unsigned short sum1 = 0xff, sum2 = 0xff; size_t tlen; while (bytes) { tlen = bytes >= 20 ? 20 : bytes; bytes -= tlen; do { sum2 += sum1 += *data++; } while (--tlen); sum1 = (sum1 & 0xff) + (sum1 >> 8); sum2 = (sum2 & 0xff) + (sum2 >> 8); } /* Second reduction step to reduce sums to 8 bits */ sum1 = (sum1 & 0xff) + (sum1 >> 8); sum2 = (sum2 & 0xff) + (sum2 >> 8); *result2 = (sum2 & 0xff); *result1 = (sum1 & 0xff); // return sum2 << 8 | sum1; } // This is a variant of fletcher16 with a 16 bit sum instead of an 8 bit sum, // and modulo 2^16 instead of 2^16-1 void hw_ostc3_firmware_checksum (unsigned char *result1, unsigned char *result2, unsigned char *result3, unsigned char *result4, unsigned char const *data, size_t bytes ) { unsigned short low = 0; unsigned short high = 0; for (unsigned int i = 0; i < bytes; i++) { low += data[i]; high += low; } *result1 = (low & 0xff); *result2 = (low/256 & 0xff); *result3 = (unsigned char)(high & 0xff); *result4 = (unsigned char)((high/256) & 0xff); // return (((unsigned int)high) << 16) + low; } int main(int argc, char** argv) { FILE *fp, * fpout; size_t lenTotal,lenTemp; unsigned char buf[2000000]; char *file = argv[1]; char *file2 = argv[2]; char *file3 = argv[3]; unsigned int pruefsumme; unsigned char buf2[4]; printf("1: %s\n", file); printf("2: %s\n", file2); printf("3: %s\n", file3); printf("\n"); //write File with length and cheksum char filename[500], filenameout[510] ; sprintf(filename,"%s",file); int filelength = strlen(filename); filename[filelength -4] = 0; lenTotal = 0; if (NULL == (fp = fopen(file, "rb"))) { printf("Unable to open %s for reading\n", file); return -1; } lenTemp = fread(&buf[lenTotal], sizeof(char), sizeof(buf), fp); // lenTemp = fread(buf, sizeof(char), sizeof(buf), fp); lenTotal = lenTemp; printf("%d bytes read (hex: %#x )\n", lenTemp,lenTemp); fclose(fp); if(file2) { if (NULL == (fp = fopen(file2, "rb"))) { printf("Unable to open %s for reading\n", file2); return -1; } lenTemp = fread(&buf[lenTotal], sizeof(char), sizeof(buf)-lenTotal, fp); lenTotal += lenTemp; printf("%d bytes read (hex: %#x )\n", lenTemp,lenTemp); fclose(fp); } if(file3) { if (NULL == (fp = fopen(file3, "rb"))) { printf("Unable to open %s for reading\n", file3); return -1; } lenTemp = fread(&buf[lenTotal], sizeof(char), sizeof(buf)-lenTotal, fp); lenTotal += lenTemp; printf("%d bytes read (hex: %#x )\n", lenTemp,lenTemp); fclose(fp); } printf("\n"); printf("%d bytes read (hex: %#x ) total \n", lenTotal,lenTotal); time_t rawtime; time (&rawtime); struct tm *timeinfo; timeinfo = localtime(&rawtime); // sprintf(filenameout,"fwupdate_%s.bin",ctime(&rawtime)); sprintf(filenameout,"OSTC4update_%02u%02u%02u.bin",timeinfo->tm_year-100,timeinfo->tm_mon+1,timeinfo->tm_mday); fpout = fopen(filenameout, "wb"); for(int i = 0;i <lenTotal;i++) { if(fwrite(&buf[i],1,1,fpout) != 1) printf("error writing\n"); } hw_ostc3_firmware_checksum(&buf2[0],&buf2[1],&buf2[2],&buf2[3],buf,lenTotal); printf("checksum %#x %#x %#x %#x\n", buf2[0],buf2[1], buf2[2], buf2[3]); if(fwrite(&buf2[0],1,4,fpout) != 4) printf("error writing checksum\n"); ; fclose(fpout); }