Example of using the DS271 battery monitor on the ESP motor driver board using PC_12 as the OneWire interface (Any other GPIO can be used)
OneWire_Methods.cpp
- Committer:
- EmbeddedSam
- Date:
- 2019-03-04
- Revision:
- 0:de50f9a71c22
File content as of revision 0:de50f9a71c22:
#include "OneWire_Methods.h" #include "mbed.h" //Peripherals and typedefs extern DigitalInOut one_wire_pin; unsigned char OneWire_ReadByte(void) { unsigned char result=0; for (int i = 0; i < 8; i++){ result >>= 1; // shift the result to get it ready for the next bit // if result is one, then set MS bit if (OneWire_ReadBit()){result |= 0x80;} } return result; } void OneWire_WriteByte(unsigned char byte_to_write) { for (int i = 0; i<8; i++) // Loop to write each bit in the byte, LS-bit first { OneWire_WriteBit(byte_to_write & 0x01); byte_to_write >>= 1; // shift the data byte for the next bit } } bool OneWire_ReadBit(void) { bool result; one_wire_pin.output(); one_wire_pin = 0; OneWire_Delay('A'); one_wire_pin.input(); one_wire_pin.mode(PullUp); OneWire_Delay('E'); result = one_wire_pin.read(); OneWire_Delay('F'); return result; } void OneWire_WriteBit (bool bit_to_write){ if (bit_to_write == 1) { // Write '1' bit one_wire_pin.output(); one_wire_pin = 0; OneWire_Delay('A'); one_wire_pin.input(); one_wire_pin.mode(PullUp); OneWire_Delay('B'); } else { one_wire_pin.output(); one_wire_pin = 0; OneWire_Delay('C'); one_wire_pin.input(); OneWire_Delay('D'); } } bool OneWire_Reset (void) { //Checks whether there is a device connected, returns true or false //Debugging console output can be used if it is defined bool result = false; one_wire_pin.output(); one_wire_pin.write(0); //Pull the line high OneWire_Delay('H'); one_wire_pin.input(); one_wire_pin.mode(PullUp); OneWire_Delay('I'); if(one_wire_pin.read() == 0){ result = true;} OneWire_Delay('J'); #ifdef Debugging pc.printf("\n\rResult from reset: %d",result); #endif return result; } void OneWire_TestDelays(void) { //Cycles the output pin through all the delays so you //can see whether they are all the right timings. one_wire_pin.output(); for(int i=0;i<6;i++){ one_wire_pin = !one_wire_pin; //toggle the pin 6 times to signal start of test at 100us wait_us(100); } OneWire_Delay('A'); one_wire_pin = !one_wire_pin; OneWire_Delay('A'); one_wire_pin = !one_wire_pin; OneWire_Delay('B'); one_wire_pin = !one_wire_pin; OneWire_Delay('B'); one_wire_pin = !one_wire_pin; OneWire_Delay('C'); one_wire_pin = !one_wire_pin; OneWire_Delay('C'); one_wire_pin = !one_wire_pin; OneWire_Delay('D'); one_wire_pin = !one_wire_pin; OneWire_Delay('D'); one_wire_pin = !one_wire_pin; OneWire_Delay('E'); one_wire_pin = !one_wire_pin; OneWire_Delay('E'); one_wire_pin = !one_wire_pin; OneWire_Delay('F'); one_wire_pin = !one_wire_pin; OneWire_Delay('F'); one_wire_pin = !one_wire_pin; OneWire_Delay('G'); one_wire_pin = !one_wire_pin; OneWire_Delay('G'); one_wire_pin = !one_wire_pin; OneWire_Delay('H'); one_wire_pin = !one_wire_pin; OneWire_Delay('H'); one_wire_pin = !one_wire_pin; OneWire_Delay('I'); one_wire_pin = !one_wire_pin; OneWire_Delay('I'); one_wire_pin = !one_wire_pin; OneWire_Delay('J'); one_wire_pin = !one_wire_pin; OneWire_Delay('J'); one_wire_pin = !one_wire_pin; } //Functions void OneWire_Delay(char letter) { //Recommended delays from Maxim (standard speed not overdrive) //https://www.maximintegrated.com/en/app-notes/index.mvp/id/126 //Letter Speed Recommended (µs) //A Standard 6 //B Standard 64 //C Standard 60 //D Standard 10 //E Standard 9 //F Standard 55 //G Standard 0 //H Standard 480 //I Standard 70 //J Standard 410 switch(letter) { case 'A': wait_us(1); break; case 'B': wait_us(64); break; case 'C': wait_us(60); break; case 'D': wait_us(10); break; case 'E': wait_us(5); break; case 'F': wait_us(55); break; case 'G': wait_us(0); break; case 'H': wait_us(480); break; case 'I': wait_us(70); break; case 'J': wait_us(410); break; default: break; } }