Liviu Radoi / DS1820-EM

DS1820-EM

Fork of DS1820 by HM Yoong

DS1Wire.cpp@2:8e118d297c83, 2014-05-27 (annotated)

Committer:
liviur2
Date:
Tue May 27 17:03:27 2014 +0000
Revision:
2:8e118d297c83
Parent:
1:78f2fa466c55 
small changes

Who changed what in which revision?

UserRevisionLine numberNew contents of line
liviur2 1:78f2fa466c55 1 #include "DS1Wire.h"
liviur2 1:78f2fa466c55 2 #include "mbed.h"
liviur2 1:78f2fa466c55 3 #include <stdint.h>
liviur2 1:78f2fa466c55 4
liviur2 1:78f2fa466c55 5 // Timing delay for 1-wire serial standard option
liviur2 1:78f2fa466c55 6 enum DELAY { A = 6, B = 64, C = 60, D = 10, E = 9, F = 55, G = 0, H = 480, I = 70, J = 410 };
liviur2 1:78f2fa466c55 7
liviur2 1:78f2fa466c55 8
liviur2 1:78f2fa466c55 9 int Reset(DigitalInOut& pin) {
liviur2 1:78f2fa466c55 10 pin.output();
liviur2 1:78f2fa466c55 11 pin = 0; // drive bus low
liviur2 1:78f2fa466c55 12 wait_us(H);
liviur2 1:78f2fa466c55 13 pin.input(); // release bus
liviur2 1:78f2fa466c55 14 wait_us(I);
liviur2 1:78f2fa466c55 15 uint32_t result = pin; // read bus value
liviur2 1:78f2fa466c55 16 wait_us(J);
liviur2 1:78f2fa466c55 17 return result;
liviur2 1:78f2fa466c55 18 }
liviur2 1:78f2fa466c55 19
liviur2 1:78f2fa466c55 20 void WriteBit(DigitalInOut& pin, uint32_t bit) {
liviur2 1:78f2fa466c55 21 pin.output();
liviur2 1:78f2fa466c55 22 if (bit) {
liviur2 1:78f2fa466c55 23 pin = 0; // drive bus low
liviur2 1:78f2fa466c55 24 wait_us(A); // delay A
liviur2 1:78f2fa466c55 25 pin.input(); // release bus
liviur2 1:78f2fa466c55 26 wait_us(B); // delay B
liviur2 1:78f2fa466c55 27 } else {
liviur2 1:78f2fa466c55 28 pin = 0; // drive bus low
liviur2 1:78f2fa466c55 29 wait_us(C); // delay C
liviur2 1:78f2fa466c55 30 pin.input(); // release bus
liviur2 1:78f2fa466c55 31 wait_us(D); // delay D
liviur2 1:78f2fa466c55 32 }
liviur2 1:78f2fa466c55 33 }
liviur2 1:78f2fa466c55 34
liviur2 1:78f2fa466c55 35 uint32_t ReadBit(DigitalInOut& pin) {
liviur2 1:78f2fa466c55 36 uint32_t bit_value;
liviur2 1:78f2fa466c55 37 pin.output();
liviur2 1:78f2fa466c55 38 pin = 0; // drive bus low
liviur2 1:78f2fa466c55 39 wait_us(A); // delay A
liviur2 1:78f2fa466c55 40 pin.input(); // release bus
liviur2 1:78f2fa466c55 41 wait_us(E); // delay E
liviur2 1:78f2fa466c55 42 bit_value = pin; // master sample bus
liviur2 1:78f2fa466c55 43 wait_us(F);
liviur2 1:78f2fa466c55 44 return bit_value;
liviur2 1:78f2fa466c55 45 }
liviur2 1:78f2fa466c55 46
liviur2 1:78f2fa466c55 47 void WriteByte(DigitalInOut& pin, uint32_t byte) {
liviur2 1:78f2fa466c55 48 for (uint32_t bit = 0; bit < 8; ++bit) {
liviur2 1:78f2fa466c55 49 WriteBit(pin, byte & 0x01); // lsb to msb
liviur2 1:78f2fa466c55 50 byte >>= 1; // right shift by 1-bit
liviur2 1:78f2fa466c55 51 }
liviur2 1:78f2fa466c55 52 }
liviur2 1:78f2fa466c55 53
liviur2 1:78f2fa466c55 54 uint32_t ReadByte(DigitalInOut& pin) {
liviur2 1:78f2fa466c55 55 uint32_t byte = 0;
liviur2 1:78f2fa466c55 56 for (uint32_t bit = 0; bit < 8; ++bit) {
liviur2 1:78f2fa466c55 57 byte |= (ReadBit(pin) << bit); // Reads lsb to msb
liviur2 1:78f2fa466c55 58 }
liviur2 1:78f2fa466c55 59 return byte;
liviur2 1:78f2fa466c55 60 }