Automatic/Manual lights+AC connected over Wifi
Dependents: ACandLightsandWifi ACandLightsandWifi
Fork of DS1820 by
Diff: DS1820.cpp
- Revision:
- 2:ee820a991b95
- Parent:
- 1:6a427f54e82c
- Child:
- 3:cf4f0ea711a7
--- a/DS1820.cpp Wed Dec 14 20:22:16 2011 +0000 +++ b/DS1820.cpp Thu Dec 15 19:07:36 2011 +0000 @@ -1,390 +0,0 @@ -#include "DS1820.h" -#include "mbed.h" - -// Global variables shared between all DS1820 objects -bool DS1820_done_flag; -int DS1820_last_descrepancy; -char DS1820_search_ROM[8]; - - -DS1820::DS1820 (PinName data_pin, PinName power_pin) : _datapin(data_pin), _parasitepin(power_pin) { - int byte_counter; - _parasite_power = true; - for(byte_counter=0;byte_counter<8;byte_counter++) - ROM[byte_counter] = 0xFF; - for(byte_counter=0;byte_counter<9;byte_counter++) - RAM[byte_counter] = 0x00; -} -DS1820::DS1820 (PinName data_pin) : _datapin(data_pin), _parasitepin(NC) { - int byte_counter; - _parasite_power = false; - for(byte_counter=0;byte_counter<8;byte_counter++) - ROM[byte_counter] = 0xFF; - for(byte_counter=0;byte_counter<9;byte_counter++) - RAM[byte_counter] = 0x00; -} - -bool DS1820::onewire_reset() { -// This will return false if no devices are present on the data bus - bool presence=false; - _datapin.output(); - _datapin = 0; // bring low for 500 us - wait_us(500); - _datapin.input(); // let the data line float high - wait_us(90); // wait 90us - if (_datapin.read()==0) // see if any devices are pulling the data line low - presence=true; - wait_us(410); - return presence; -} - -void DS1820::onewire_bit_out (bool bit_data) { - _datapin.output(); - _datapin = 0; - wait_us(5); - if (bit_data) { - _datapin.input(); // bring data line high - wait_us(55); - } else { - wait_us(55); // keep data line low - _datapin.input(); - } -} - -void DS1820::onewire_byte_out(char data) { // output data character (least sig bit first). - int n; - for (n=0; n<8; n++) { - onewire_bit_out(data & 0x01); - data = data >> 1; // now the next bit is in the least sig bit position. - } -} - -bool DS1820::onewire_bit_in() { - bool answer; - _datapin.output(); - _datapin = 0; - wait_us(5); - _datapin.input(); - wait_us(5); - answer = _datapin.read(); - wait_us(50); - return answer; -} - -char DS1820::onewire_byte_in() { // read byte, least sig byte first - char answer = 0x00; - int i; - for (i=0; i<8; i++) { - answer = answer >> 1; // shift over to make room for the next bit - if (onewire_bit_in()) - answer = answer | 0x80; // if the data port is high, make this bit a 1 - } - return answer; -} - -bool DS1820::search_ROM() { - return search_ROM_routine(0xF0); // Search ROM command -} - -bool DS1820::search_alarm() { - return search_ROM_routine(0xEC); // Search Alarm command -} - -bool DS1820::search_ROM_routine(char command) { - extern bool DS1820_done_flag; - extern int DS1820_last_descrepancy; - extern char DS1820_search_ROM[8]; - int descrepancy_marker, ROM_bit_index; - bool return_value, Bit_A, Bit_B; - char byte_counter, bit_mask; - - return_value=false; - if (!DS1820_done_flag) { - if (!onewire_reset()) { - DS1820_last_descrepancy = 0; // no devices present - } else { - ROM_bit_index=1; - descrepancy_marker=0; - onewire_byte_out(command); // Search ROM command or Search Alarm command - byte_counter = 0; - bit_mask = 0x01; - while (ROM_bit_index<=64) { - Bit_A = onewire_bit_in(); - Bit_B = onewire_bit_in(); - if (Bit_A & Bit_B) { - descrepancy_marker = 0; // data read error, this should never happen - ROM_bit_index = 0xFF; - } else { - if (Bit_A | Bit_B) { - // Set ROM bit to Bit_A - if (Bit_A) { - DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] | bit_mask; // Set ROM bit to one - } else { - DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] & ~bit_mask; // Set ROM bit to zero - } - } else { - // both bits A and B are low, so there are two or more devices present - if ( ROM_bit_index == DS1820_last_descrepancy ) { - DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] | bit_mask; // Set ROM bit to one - } else { - if ( ROM_bit_index > DS1820_last_descrepancy ) { - DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] & ~bit_mask; // Set ROM bit to zero - descrepancy_marker = ROM_bit_index; - } else { - if (( DS1820_search_ROM[byte_counter] & bit_mask) == 0x00 ) - descrepancy_marker = ROM_bit_index; - } - } - } - onewire_bit_out (DS1820_search_ROM[byte_counter] & bit_mask); - ROM_bit_index++; - if (bit_mask & 0x80) { - byte_counter++; - bit_mask = 0x01; - } else { - bit_mask = bit_mask << 1; - } - } - } - DS1820_last_descrepancy = descrepancy_marker; - if (ROM_bit_index != 0xFF) { - for(byte_counter=0;byte_counter<8;byte_counter++) - ROM[byte_counter] = DS1820_search_ROM[byte_counter]; - return_value = true; - } - } - if (DS1820_last_descrepancy == 0) - DS1820_done_flag = true; - } - return return_value; -} - -void DS1820::search_ROM_setup() { - extern bool DS1820_done_flag; - extern int DS1820_last_descrepancy; - extern char DS1820_search_ROM[8]; - DS1820_done_flag = false; - DS1820_last_descrepancy = 0; - int i; - for (i=0; i<8; i++) - DS1820_search_ROM[i]=0x00; -} - -void DS1820::read_ROM() { - // NOTE: This command can only be used when there is one DS1820 on the bus. If this command - // is used when there is more than one slave present on the bus, a data collision will occur - // when all the DS1820s attempt to respond at the same time. - int i; - onewire_reset(); - onewire_byte_out(0x33); // Read ROM id - for (i=0; i<8; i++) - ROM[i]=onewire_byte_in(); -} - -void DS1820::match_ROM() { -// Used to select a specific device - int i; - onewire_reset(); - onewire_byte_out( 0x55); //Match ROM command - for (i=0;i<8;i++) - onewire_byte_out(ROM[i]); -} - -void DS1820::skip_ROM() { - onewire_reset(); - onewire_byte_out(0xCC); // Skip ROM command -} - -bool DS1820::ROM_checksum_error() { - char CRC=0x00; - int i; - for(i=0;i<7;i++) // Only going to shift the lower 7 bytes - CRC = CRC_byte(CRC, ROM[i]); - // After 7 bytes CRC should equal the 8th byte (ROM CRC) - return (CRC!=ROM[7]); // will return true if there is a CRC checksum error -} - -bool DS1820::RAM_checksum_error() { - char CRC=0x00; - int i; - read_RAM(); - for(i=0;i<8;i++) // Only going to shift the lower 8 bytes - CRC = CRC_byte(CRC, RAM[i]); - // After 8 bytes CRC should equal the 9th byte (RAM CRC) - return (CRC!=RAM[8]); // will return true if there is a CRC checksum error -} - -char DS1820::CRC_byte (char CRC, char byte ) { - int j; - for(j=0;j<8;j++) { - if ((byte & 0x01 ) ^ (CRC & 0x01)) { - // DATA ^ LSB CRC = 1 - CRC = CRC>>1; - // Set the MSB to 1 - CRC = CRC | 0x80; - // Check bit 3 - if (CRC & 0x04) { - CRC = CRC & 0xFB; // Bit 3 is set, so clear it - } else { - CRC = CRC | 0x04; // Bit 3 is clear, so set it - } - // Check bit 4 - if (CRC & 0x08) { - CRC = CRC & 0xF7; // Bit 4 is set, so clear it - } else { - CRC = CRC | 0x08; // Bit 4 is clear, so set it - } - } else { - // DATA ^ LSB CRC = 0 - CRC = CRC>>1; - // clear MSB - CRC = CRC & 0x7F; - // No need to check bits, with DATA ^ LSB CRC = 0, they will remain unchanged - } - byte = byte>>1; - } -return CRC; -} - -void DS1820::convert_temperature(devices device) { - // Convert temperature into scratchpad RAM for all devices at once - int delay_time = 750; // Default delay time - char resolution; - if (device==all_devices) - skip_ROM(); // Skip ROM command, will convert for ALL devices - else { - match_ROM(); - if (FAMILY_CODE == FAMILY_CODE_DS18B20 ) { - resolution = RAM[4] & 0x60; - if (resolution == 0x00) // 9 bits - delay_time = 94; - if (resolution == 0x20) // 10 bits - delay_time = 188; - if (resolution == 0x40) // 11 bits. Note 12bits uses the 750ms default - delay_time = 375; - } - } - onewire_byte_out( 0x44); // perform temperature conversion - if (_parasite_power) - _parasitepin = 1; // Parasite power strong pullup - wait_ms(delay_time); - if (_parasite_power) - _parasitepin = 0; -} - -void DS1820::read_RAM() { - // This will copy the DS1820's 9 bytes of RAM data - // into the objects RAM array. Functions that use - // RAM values will automaticly call this procedure. - int i; - match_ROM(); // Select this device - onewire_byte_out( 0xBE); //Read Scratchpad command - for(i=0;i<9;i++) { - RAM[i] = onewire_byte_in(); - } -} - -bool DS1820::set_configuration_bits(unsigned int resolution) { - bool answer = false; - resolution = resolution - 9; - if (resolution < 4) { - resolution = resolution<<5; // align the bits - RAM[4] = (RAM[4] & 0x60) | resolution; // mask out old data, insert new - write_scratchpad ((RAM[2]<<8) + RAM[3]); -// store_scratchpad (DS1820::this_device); // Need to test if this is required - answer = true; - } - return answer; -} - -int DS1820::read_scratchpad() { - int answer; - read_RAM(); - answer = (RAM[2]<<8) + RAM[3]; - return answer; -} - -void DS1820::write_scratchpad(int data) { - RAM[3] = data; - RAM[2] = data>>8; - match_ROM(); - onewire_byte_out(0x4E); // Copy scratchpad into DS1820 ram memory - onewire_byte_out(RAM[2]); // T(H) - onewire_byte_out(RAM[3]); // T(L) - if ( FAMILY_CODE == FAMILY_CODE_DS18B20 ) { - onewire_byte_out(RAM[4]); // Configuration register - } -} - -void DS1820::store_scratchpad(devices device) { - if (device==all_devices) - skip_ROM(); // Skip ROM command, will store for ALL devices - else - match_ROM(); - onewire_byte_out(0x48); // Write scratchpad into E2 command - if (_parasite_power) - _parasitepin=1; - wait_ms(10); // Parasite power strong pullup for 10ms - if (_parasite_power) - _parasitepin=0; -} - -int DS1820::recall_scratchpad(devices device) { -// This copies the E2 values into the DS1820's memory. -// If you specify all_devices this will return zero, otherwise -// it will return the value of the scratchpad memory. - int answer=0; - if (device==all_devices) - skip_ROM(); // Skip ROM command, will recall for ALL devices - else - match_ROM(); - onewire_byte_out(0xB8); // Recall E2 data to scratchpad command - wait_ms(10); // not sure I like polling for completion - // it could cause an infinite loop - if (device==DS1820::this_device) { - read_RAM(); - answer = read_scratchpad(); - } - return answer; -} - -float DS1820::temperature(char scale) { -// The data specs state that count_per_degree should be 0x10 (16), I found my devices -// to have a count_per_degree of 0x4B (75). With the standard resolution of 1/2 deg C -// this allowed an expanded resolution of 1/150th of a deg C. I wouldn't rely on this -// being super acurate, but it does allow for a smooth display in the 1/10ths of a -// deg C or F scales. - float answer, remaining_count, count_per_degree; - int reading; - read_RAM(); - reading = (RAM[1] << 8) + RAM[0]; - if (reading & 0x8000) { // negative degrees C - reading = 0-((reading ^ 0xffff) + 1); // 2's comp then convert to signed int - } - answer = reading +0.0; // convert to floating point - if ( FAMILY_CODE == FAMILY_CODE_DS18B20 ) { - answer = answer / 8.0; - } - else { - remaining_count = RAM[6]; - count_per_degree = RAM[7]; - answer = answer - 0.25 + (count_per_degree - remaining_count) / count_per_degree; - } - if (scale=='C' or scale=='c') - answer = answer / 2.0; - else - // Convert to deg F - answer = answer * 9.0 / 10.0 + 32.0; - return answer; -} - -bool DS1820::read_power_supply(devices device) { -// This will return true if the device (or all devices) are Vcc powered -// This will return false if the device (or ANY device) is parasite powered - if (device==all_devices) - skip_ROM(); // Skip ROM command, will poll for any device using parasite power - else - match_ROM(); - onewire_byte_out(0xB4); // Read power supply command - return onewire_bit_in(); -}