From 1da8626e6ed5c2a0fe085ac9d0ec3d1e21ac501d Mon Sep 17 00:00:00 2001 From: Grzegorz Hetman Date: Thu, 4 Feb 2016 19:52:57 +0100 Subject: [PATCH] Add ds18b20 driver and example. --- examples/ds18b20_onewire/Makefile | 3 + examples/ds18b20_onewire/ds18b20_onewire.c | 51 +++ extras/ds18b20/component.mk | 9 + extras/ds18b20/ds18b20.c | 111 +++++ extras/ds18b20/ds18b20.h | 20 + extras/onewire/README.md | 7 + extras/onewire/component.mk | 10 + extras/onewire/onewire.c | 494 +++++++++++++++++++++ extras/onewire/onewire.h | 163 +++++++ 9 files changed, 868 insertions(+) create mode 100644 examples/ds18b20_onewire/Makefile create mode 100644 examples/ds18b20_onewire/ds18b20_onewire.c create mode 100644 extras/ds18b20/component.mk create mode 100644 extras/ds18b20/ds18b20.c create mode 100644 extras/ds18b20/ds18b20.h create mode 100644 extras/onewire/README.md create mode 100644 extras/onewire/component.mk create mode 100644 extras/onewire/onewire.c create mode 100644 extras/onewire/onewire.h diff --git a/examples/ds18b20_onewire/Makefile b/examples/ds18b20_onewire/Makefile new file mode 100644 index 0000000..c856e7e --- /dev/null +++ b/examples/ds18b20_onewire/Makefile @@ -0,0 +1,3 @@ +PROGRAM=ds18b20_onewire +EXTRA_COMPONENTS = extras/onewire extras/ds18b20 +include ../../common.mk diff --git a/examples/ds18b20_onewire/ds18b20_onewire.c b/examples/ds18b20_onewire/ds18b20_onewire.c new file mode 100644 index 0000000..d856344 --- /dev/null +++ b/examples/ds18b20_onewire/ds18b20_onewire.c @@ -0,0 +1,51 @@ +/* ds18b20 - Retrieves temperature from ds18b20 sensors and print it out. + * + * This sample code is in the public domain., + */ +#include "espressif/esp_common.h" +#include "esp/uart.h" + +#include "FreeRTOS.h" +#include "task.h" +#include "timers.h" +#include "queue.h" + +// DS18B20 driver +#include "ds18b20/ds18b20.h" + +void print_temperature(void *pvParameters) +{ + int delay = 500; + uint8_t amount = 0; + uint8_t sensors = 2; + DSENSOR t[sensors]; + + // Use GPIO 13 as one wire pin. + uint8_t GPIO_FOR_ONE_WIRE = 13; + + while(1) { + // Search all DS18B20, return its amount and feed 't' structure with result data. + amount = readDS18B20(GPIO_FOR_ONE_WIRE, t); + + if (amount < sensors){ + printf("Something is wrong, I expect to see %d sensors \nbut just %d was detected!\n", sensors, amount); + } + + for (int i = 0; i < amount; ++i) + { + printf("Sensor %d report: %d.%d C\n",t[i].id, t[i].major, t[i].minor); + } + printf("\n"); + vTaskDelay(delay / portTICK_RATE_MS); + } +} + +void user_init(void) +{ + uart_set_baud(0, 115200); + + printf("SDK version:%s\n", sdk_system_get_sdk_version()); + + xTaskCreate(&print_temperature, (signed char *)"get_task", 256, NULL, 2, NULL); +} + diff --git a/extras/ds18b20/component.mk b/extras/ds18b20/component.mk new file mode 100644 index 0000000..866371c --- /dev/null +++ b/extras/ds18b20/component.mk @@ -0,0 +1,9 @@ +# Component makefile for extras/ds18b20 + +# expected anyone using bmp driver includes it as 'ds18b20/ds18b20.h' +INC_DIRS += $(ds18b20_ROOT).. + +# args for passing into compile rule generation +ds18b20_SRC_DIR = $(ds18b20_ROOT) + +$(eval $(call component_compile_rules,ds18b20)) diff --git a/extras/ds18b20/ds18b20.c b/extras/ds18b20/ds18b20.c new file mode 100644 index 0000000..0cd213b --- /dev/null +++ b/extras/ds18b20/ds18b20.c @@ -0,0 +1,111 @@ +#include "onewire/onewire.h" +#include "ds18b20.h" + +#define DS1820_WRITE_SCRATCHPAD 0x4E +#define DS1820_READ_SCRATCHPAD 0xBE +#define DS1820_COPY_SCRATCHPAD 0x48 +#define DS1820_READ_EEPROM 0xB8 +#define DS1820_READ_PWRSUPPLY 0xB4 +#define DS1820_SEARCHROM 0xF0 +#define DS1820_SKIP_ROM 0xCC +#define DS1820_READROM 0x33 +#define DS1820_MATCHROM 0x55 +#define DS1820_ALARMSEARCH 0xEC +#define DS1820_CONVERT_T 0x44 + +uint8_t readDS18B20(uint8_t pin, DSENSOR *result){ + static uint8_t one_time = 1; + + if (one_time){ + onewire_init(pin); + one_time = 0; + } + + uint8_t addr[8]; + uint8_t sensor_id = 0; + onewire_reset_search(pin); + + while(onewire_search(pin, addr)){ + uint8_t crc = onewire_crc8(addr, 7); + if (crc != addr[7]){ + printf("CRC check failed: %02X %02X\n", addr[7], crc); + return 0; + } + + onewire_reset(pin); + onewire_select(pin, addr); + onewire_write(pin, DS1820_CONVERT_T, owDefaultPower); + sdk_os_delay_us(750); + onewire_reset(pin); + onewire_select(pin, addr); + onewire_write(pin, DS1820_READ_SCRATCHPAD, owDefaultPower); + + uint8_t get[10]; + + for (int k=0;k<9;k++){ + get[k]=onewire_read(pin); + } + + //printf("\n ScratchPAD DATA = %X %X %X %X %X %X %X %X %X\n",get[8],get[7],get[6],get[5],get[4],get[3],get[2],get[1],get[0]); + crc = onewire_crc8(get, 8); + + if (crc != get[8]){ + printf("CRC check failed: %02X %02X\n", get[8], crc); + return 0; + } + + uint8_t temp_msb = get[1]; // Sign byte + lsbit + uint8_t temp_lsb = get[0]; // Temp data plus lsb + uint16_t temp = temp_msb << 8 | temp_lsb; + + float temperature; + + temperature = (temp * 625.0)/10000; + //printf("Got a DS18B20 Reading: %d.%d\n", (int)temperature, (int)(temperature - (int)temperature) * 100); + result[sensor_id].id = sensor_id; + result[sensor_id].major = (int)temperature; + result[sensor_id].minor = (int)(temperature) - (int)temperature * 100; + sensor_id++; + } + return sensor_id; +} + +float read_single_DS18B20(uint8_t pin){ + + onewire_init(pin); + onewire_reset(pin); + + onewire_write(pin, DS1820_SKIP_ROM, owDefaultPower); + onewire_write(pin, DS1820_CONVERT_T, owDefaultPower); + + sdk_os_delay_us(750); + + onewire_reset(pin); + onewire_write(pin, DS1820_SKIP_ROM, owDefaultPower); + onewire_write(pin, DS1820_READ_SCRATCHPAD, owDefaultPower); + + uint8_t get[10]; + + for (int k=0;k<9;k++){ + get[k]=onewire_read(pin); + } + + //printf("\n ScratchPAD DATA = %X %X %X %X %X %X %X %X %X\n",get[8],get[7],get[6],get[5],get[4],get[3],get[2],get[1],get[0]); + uint8_t crc = onewire_crc8(get, 8); + + if (crc != get[8]){ + printf("CRC check failed: %02X %02X", get[8], crc); + return 0; + } + + uint8_t temp_msb = get[1]; // Sign byte + lsbit + uint8_t temp_lsb = get[0]; // Temp data plus lsb + + uint16_t temp = temp_msb << 8 | temp_lsb; + + float temperature; + + temperature = (temp * 625.0)/10000; + return temperature; + //printf("Got a DS18B20 Reading: %d.%d\n", (int)temperature, (int)(temperature - (int)temperature) * 100); +} \ No newline at end of file diff --git a/extras/ds18b20/ds18b20.h b/extras/ds18b20/ds18b20.h new file mode 100644 index 0000000..b957a4e --- /dev/null +++ b/extras/ds18b20/ds18b20.h @@ -0,0 +1,20 @@ +#ifndef DRIVER_DS18B20_H_ +#define DRIVER_DS18B20_H_ + +typedef struct DSENSOR { + uint8_t id; + uint8_t major; + uint8_t minor; +} DSENSOR; + +// Scan all ds18b20 sensors on bus and return its amount. +// Result are saved in array of DSENSOR structure. +// Cause printf in esp sdk don`t support float, +// I split result as two number (major, minor). +uint8_t readDS18B20(uint8_t pin, DSENSOR *result); + +// This method is just to demonstrate how to read +// temperature from single dallas chip. +float read_single_DS18B20(uint8_t pin); + +#endif diff --git a/extras/onewire/README.md b/extras/onewire/README.md new file mode 100644 index 0000000..288f50b --- /dev/null +++ b/extras/onewire/README.md @@ -0,0 +1,7 @@ +# Yet another one wire driver for the ESP8266 + +This is a port of bit banging one wire driver based on nodemcu implementaion. + +For all aspect regarding license, please check in their code. + + diff --git a/extras/onewire/component.mk b/extras/onewire/component.mk new file mode 100644 index 0000000..c453b58 --- /dev/null +++ b/extras/onewire/component.mk @@ -0,0 +1,10 @@ +# Component makefile for extras/onewire + +# expected anyone using onewire driver includes it as 'onewire/onewire.h' +INC_DIRS += $(onewire_ROOT).. + +# args for passing into compile rule generation +onewire_INC_DIR = +onewire_SRC_DIR = $(onewire_ROOT) + +$(eval $(call component_compile_rules,onewire)) diff --git a/extras/onewire/onewire.c b/extras/onewire/onewire.c new file mode 100644 index 0000000..eb034b0 --- /dev/null +++ b/extras/onewire/onewire.c @@ -0,0 +1,494 @@ +#include "onewire.h" + +#if ONEWIRE_SEARCH +// global search state +static unsigned char ROM_NO[NUM_OW][8]; +static uint8_t LastDiscrepancy[NUM_OW]; +static uint8_t LastFamilyDiscrepancy[NUM_OW]; +static uint8_t LastDeviceFlag[NUM_OW]; +#endif + +//#define noInterrupts void() +// gpio_enable(gpio, GPIO_OUTPUT); + +void onewire_init(uint8_t pin) +{ + // pinMode(pin, INPUT); + gpio_enable(pin, GPIO_INPUT); + //platform_gpio_mode(pin, PLATFORM_GPIO_INPUT, PLATFORM_GPIO_PULLUP); +#if ONEWIRE_SEARCH + onewire_reset_search(pin); +#endif +} + + +// Perform the onewire reset function. We will wait up to 250uS for +// the bus to come high, if it doesn't then it is broken or shorted +// and we return a 0; +// +// Returns 1 if a device asserted a presence pulse, 0 otherwise. +// +uint8_t onewire_reset(uint8_t pin) +{ + uint8_t r; + uint8_t retries = 125; + + noInterrupts(); + DIRECT_MODE_INPUT(pin); + interrupts(); + // wait until the wire is high... just in case + do { + if (--retries == 0) return 0; + delayMicroseconds(2); + } while ( !DIRECT_READ(pin)); + + noInterrupts(); + DIRECT_WRITE_LOW(pin); + DIRECT_MODE_OUTPUT(pin); // drive output low + interrupts(); + delayMicroseconds(480); + noInterrupts(); + DIRECT_MODE_INPUT(pin); // allow it to float + delayMicroseconds(70); + r = !DIRECT_READ(pin); + interrupts(); + delayMicroseconds(410); + return r; +} + +// +// Write a bit. Port and bit is used to cut lookup time and provide +// more certain timing. +// +static void onewire_write_bit(uint8_t pin, uint8_t v) +{ + if (v & 1) { + noInterrupts(); + DIRECT_WRITE_LOW(pin); + DIRECT_MODE_OUTPUT(pin); // drive output low + delayMicroseconds(10); + DIRECT_WRITE_HIGH(pin); // drive output high + interrupts(); + delayMicroseconds(55); + } else { + noInterrupts(); + DIRECT_WRITE_LOW(pin); + DIRECT_MODE_OUTPUT(pin); // drive output low + delayMicroseconds(65); + DIRECT_WRITE_HIGH(pin); // drive output high + interrupts(); + delayMicroseconds(5); + } +} + +// +// Read a bit. Port and bit is used to cut lookup time and provide +// more certain timing. +// +static uint8_t onewire_read_bit(uint8_t pin) +{ + uint8_t r; + + noInterrupts(); + DIRECT_MODE_OUTPUT(pin); + DIRECT_WRITE_LOW(pin); + delayMicroseconds(3); + DIRECT_MODE_INPUT(pin); // let pin float, pull up will raise + delayMicroseconds(10); + r = DIRECT_READ(pin); + interrupts(); + delayMicroseconds(53); + return r; +} + +// +// Write a byte. The writing code uses the active drivers to raise the +// pin high, if you need power after the write (e.g. DS18S20 in +// parasite power mode) then set 'power' to 1, otherwise the pin will +// go tri-state at the end of the write to avoid heating in a short or +// other mishap. +// +void onewire_write(uint8_t pin, uint8_t v, uint8_t power /* = 0 */) { + uint8_t bitMask; + + for (bitMask = 0x01; bitMask; bitMask <<= 1) { + onewire_write_bit(pin, (bitMask & v)?1:0); + } + if ( !power) { + noInterrupts(); + DIRECT_MODE_INPUT(pin); + DIRECT_WRITE_LOW(pin); + interrupts(); + } +} + +void onewire_write_bytes(uint8_t pin, const uint8_t *buf, uint16_t count, bool power /* = 0 */) { + uint16_t i; + for (i = 0 ; i < count ; i++) + onewire_write(pin, buf[i], owDefaultPower); + if (!power) { + noInterrupts(); + DIRECT_MODE_INPUT(pin); + DIRECT_WRITE_LOW(pin); + interrupts(); + } +} + +// +// Read a byte +// +uint8_t onewire_read(uint8_t pin) { + uint8_t bitMask; + uint8_t r = 0; + + for (bitMask = 0x01; bitMask; bitMask <<= 1) { + if (onewire_read_bit(pin)) r |= bitMask; + } + return r; +} + +void onewire_read_bytes(uint8_t pin, uint8_t *buf, uint16_t count) { + uint16_t i; + for (i = 0 ; i < count ; i++) + buf[i] = onewire_read(pin); +} + +// +// Do a ROM select +// +void onewire_select(uint8_t pin, const uint8_t rom[8]) +{ + uint8_t i; + + onewire_write(pin, 0x55, owDefaultPower); // Choose ROM + + for (i = 0; i < 8; i++) onewire_write(pin, rom[i], owDefaultPower); +} + +// +// Do a ROM skip +// +void onewire_skip(uint8_t pin) +{ + onewire_write(pin, 0xCC, owDefaultPower); // Skip ROM +} + +void onewire_depower(uint8_t pin) +{ + noInterrupts(); + DIRECT_MODE_INPUT(pin); + interrupts(); +} + +#if ONEWIRE_SEARCH + +// +// You need to use this function to start a search again from the beginning. +// You do not need to do it for the first search, though you could. +// +void onewire_reset_search(uint8_t pin) +{ + // reset the search state + LastDiscrepancy[pin] = 0; + LastDeviceFlag[pin] = FALSE; + LastFamilyDiscrepancy[pin] = 0; + int i; + for(i = 7; ; i--) { + ROM_NO[pin][i] = 0; + if ( i == 0) break; + } +} + +// Setup the search to find the device type 'family_code' on the next call +// to search(*newAddr) if it is present. +// +void onewire_target_search(uint8_t pin, uint8_t family_code) +{ + // set the search state to find SearchFamily type devices + ROM_NO[pin][0] = family_code; + uint8_t i; + for (i = 1; i < 8; i++) + ROM_NO[pin][i] = 0; + LastDiscrepancy[pin] = 64; + LastFamilyDiscrepancy[pin] = 0; + LastDeviceFlag[pin] = FALSE; +} + +// +// Perform a search. If this function returns a '1' then it has +// enumerated the next device and you may retrieve the ROM from the +// OneWire::address variable. If there are no devices, no further +// devices, or something horrible happens in the middle of the +// enumeration then a 0 is returned. If a new device is found then +// its address is copied to newAddr. Use OneWire::reset_search() to +// start over. +// +// --- Replaced by the one from the Dallas Semiconductor web site --- +//-------------------------------------------------------------------------- +// Perform the 1-Wire Search Algorithm on the 1-Wire bus using the existing +// search state. +// Return TRUE : device found, ROM number in ROM_NO buffer +// FALSE : device not found, end of search +// +uint8_t onewire_search(uint8_t pin, uint8_t *newAddr) +{ + uint8_t id_bit_number; + uint8_t last_zero, rom_byte_number, search_result; + uint8_t id_bit, cmp_id_bit; + + unsigned char rom_byte_mask, search_direction; + + // initialize for search + id_bit_number = 1; + last_zero = 0; + rom_byte_number = 0; + rom_byte_mask = 1; + search_result = 0; + + // if the last call was not the last one + if (!LastDeviceFlag[pin]) + { + // 1-Wire reset + if (!onewire_reset(pin)) + { + // reset the search + LastDiscrepancy[pin] = 0; + LastDeviceFlag[pin] = FALSE; + LastFamilyDiscrepancy[pin] = 0; + return FALSE; + } + + // issue the search command + onewire_write(pin, 0xF0, owDefaultPower); + + // loop to do the search + do + { + // read a bit and its complement + id_bit = onewire_read_bit(pin); + cmp_id_bit = onewire_read_bit(pin); + + // check for no devices on 1-wire + if ((id_bit == 1) && (cmp_id_bit == 1)) + break; + else + { + // all devices coupled have 0 or 1 + if (id_bit != cmp_id_bit) + search_direction = id_bit; // bit write value for search + else + { + // if this discrepancy if before the Last Discrepancy + // on a previous next then pick the same as last time + if (id_bit_number < LastDiscrepancy[pin]) + search_direction = ((ROM_NO[pin][rom_byte_number] & rom_byte_mask) > 0); + else + // if equal to last pick 1, if not then pick 0 + search_direction = (id_bit_number == LastDiscrepancy[pin]); + + // if 0 was picked then record its position in LastZero + if (search_direction == 0) + { + last_zero = id_bit_number; + + // check for Last discrepancy in family + if (last_zero < 9) + LastFamilyDiscrepancy[pin] = last_zero; + } + } + + // set or clear the bit in the ROM byte rom_byte_number + // with mask rom_byte_mask + if (search_direction == 1) + ROM_NO[pin][rom_byte_number] |= rom_byte_mask; + else + ROM_NO[pin][rom_byte_number] &= ~rom_byte_mask; + + // serial number search direction write bit + onewire_write_bit(pin, search_direction); + + // increment the byte counter id_bit_number + // and shift the mask rom_byte_mask + id_bit_number++; + rom_byte_mask <<= 1; + + // if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask + if (rom_byte_mask == 0) + { + rom_byte_number++; + rom_byte_mask = 1; + } + } + } + while(rom_byte_number < 8); // loop until through all ROM bytes 0-7 + + // if the search was successful then + if (!(id_bit_number < 65)) + { + // search successful so set LastDiscrepancy,LastDeviceFlag,search_result + LastDiscrepancy[pin] = last_zero; + + // check for last device + if (LastDiscrepancy[pin] == 0) + LastDeviceFlag[pin] = TRUE; + + search_result = TRUE; + } + } + + // if no device found then reset counters so next 'search' will be like a first + if (!search_result || !ROM_NO[pin][0]) + { + LastDiscrepancy[pin] = 0; + LastDeviceFlag[pin] = FALSE; + LastFamilyDiscrepancy[pin] = 0; + search_result = FALSE; + } + else + { + for (rom_byte_number = 0; rom_byte_number < 8; rom_byte_number++) + { + newAddr[rom_byte_number] = ROM_NO[pin][rom_byte_number]; + //printf("Ok I found something at %d - %x...\n",rom_byte_number, newAddr[rom_byte_number]); + } + } + return search_result; +} + +#endif + + +#if ONEWIRE_CRC +// The 1-Wire CRC scheme is described in Maxim Application Note 27: +// "Understanding and Using Cyclic Redundancy Checks with Maxim iButton Products" +// + +#if ONEWIRE_CRC8_TABLE +// This table comes from Dallas sample code where it is freely reusable, +// though Copyright (C) 2000 Dallas Semiconductor Corporation +static const uint8_t dscrc_table[] = { + 0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65, + 157,195, 33,127,252,162, 64, 30, 95, 1,227,189, 62, 96,130,220, + 35,125,159,193, 66, 28,254,160,225,191, 93, 3,128,222, 60, 98, + 190,224, 2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255, + 70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89, 7, + 219,133,103, 57,186,228, 6, 88, 25, 71,165,251,120, 38,196,154, + 101, 59,217,135, 4, 90,184,230,167,249, 27, 69,198,152,122, 36, + 248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91, 5,231,185, + 140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205, + 17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80, + 175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238, + 50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115, + 202,148,118, 40,171,245, 23, 73, 8, 86,180,234,105, 55,213,139, + 87, 9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22, + 233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168, + 116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53}; + +#ifndef pgm_read_byte +#define pgm_read_byte(addr) (*(const uint8_t *)(addr)) +#endif + +// +// Compute a Dallas Semiconductor 8 bit CRC. These show up in the ROM +// and the registers. (note: this might better be done without to +// table, it would probably be smaller and certainly fast enough +// compared to all those delayMicrosecond() calls. But I got +// confused, so I use this table from the examples.) +// +uint8_t onewire_crc8(const uint8_t *addr, uint8_t len) +{ + uint8_t crc = 0; + + while (len--) { + crc = pgm_read_byte(dscrc_table + (crc ^ *addr++)); + } + return crc; +} +#else +// +// Compute a Dallas Semiconductor 8 bit CRC directly. +// this is much slower, but much smaller, than the lookup table. +// +uint8_t onewire_crc8(const uint8_t *addr, uint8_t len) +{ + uint8_t crc = 0; + + while (len--) { + uint8_t inbyte = *addr++; + uint8_t i; + for (i = 8; i; i--) { + uint8_t mix = (crc ^ inbyte) & 0x01; + crc >>= 1; + if (mix) crc ^= 0x8C; + inbyte >>= 1; + } + } + return crc; +} +#endif + +#if ONEWIRE_CRC16 +// Compute the 1-Wire CRC16 and compare it against the received CRC. +// Example usage (reading a DS2408): + // // Put everything in a buffer so we can compute the CRC easily. +// uint8_t buf[13]; +// buf[0] = 0xF0; // Read PIO Registers +// buf[1] = 0x88; // LSB address +// buf[2] = 0x00; // MSB address +// WriteBytes(net, buf, 3); // Write 3 cmd bytes +// ReadBytes(net, buf+3, 10); // Read 6 data bytes, 2 0xFF, 2 CRC16 +// if (!CheckCRC16(buf, 11, &buf[11])) { +// // Handle error. +// } +// +// @param input - Array of bytes to checksum. +// @param len - How many bytes to use. +// @param inverted_crc - The two CRC16 bytes in the received data. +// This should just point into the received data, +// *not* at a 16-bit integer. +// @param crc - The crc starting value (optional) +// @return True, iff the CRC matches. +bool onewire_check_crc16(const uint8_t* input, uint16_t len, const uint8_t* inverted_crc, uint16_t crc) +{ + crc = ~onewire_crc16(input, len, crc); + return (crc & 0xFF) == inverted_crc[0] && (crc >> 8) == inverted_crc[1]; +} + +// Compute a Dallas Semiconductor 16 bit CRC. This is required to check +// the integrity of data received from many 1-Wire devices. Note that the +// CRC computed here is *not* what you'll get from the 1-Wire network, +// for two reasons: +// 1) The CRC is transmitted bitwise inverted. +// 2) Depending on the endian-ness of your processor, the binary +// representation of the two-byte return value may have a different +// byte order than the two bytes you get from 1-Wire. +// @param input - Array of bytes to checksum. +// @param len - How many bytes to use. +// @param crc - The crc starting value (optional) +// @return The CRC16, as defined by Dallas Semiconductor. +uint16_t onewire_crc16(const uint8_t* input, uint16_t len, uint16_t crc) +{ + static const uint8_t oddparity[16] = + { 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0 }; + + uint16_t i; + for (i = 0 ; i < len ; i++) { + // Even though we're just copying a byte from the input, + // we'll be doing 16-bit computation with it. + uint16_t cdata = input[i]; + cdata = (cdata ^ crc) & 0xff; + crc >>= 8; + + if (oddparity[cdata & 0x0F] ^ oddparity[cdata >> 4]) + crc ^= 0xC001; + + cdata <<= 6; + crc ^= cdata; + cdata <<= 1; + crc ^= cdata; + } + return crc; +} +#endif + +#endif diff --git a/extras/onewire/onewire.h b/extras/onewire/onewire.h new file mode 100644 index 0000000..7c86baa --- /dev/null +++ b/extras/onewire/onewire.h @@ -0,0 +1,163 @@ +#ifndef __ONEWIRE_H__ +#define __ONEWIRE_H__ + +#include // sdk_os_delay_us +#include "FreeRTOS.h" + +// 1 for keeping the parasitic power on H +#define owDefaultPower 1 + +#define NUM_OW 20 +#define FALSE 0 +#define TRUE 1 + +// You can exclude certain features from OneWire. In theory, this +// might save some space. In practice, the compiler automatically +// removes unused code (technically, the linker, using -fdata-sections +// and -ffunction-sections when compiling, and Wl,--gc-sections +// when linking), so most of these will not result in any code size +// reduction. Well, unless you try to use the missing features +// and redesign your program to not need them! ONEWIRE_CRC8_TABLE +// is the exception, because it selects a fast but large algorithm +// or a small but slow algorithm. + +// you can exclude onewire_search by defining that to 0 +#ifndef ONEWIRE_SEARCH +#define ONEWIRE_SEARCH 1 +#endif + +// You can exclude CRC checks altogether by defining this to 0 +#ifndef ONEWIRE_CRC +#define ONEWIRE_CRC 1 +#endif + +// Select the table-lookup method of computing the 8-bit CRC +// by setting this to 1. The lookup table enlarges code size by +// about 250 bytes. It does NOT consume RAM (but did in very +// old versions of OneWire). If you disable this, a slower +// but very compact algorithm is used. +#ifndef ONEWIRE_CRC8_TABLE +//#define ONEWIRE_CRC8_TABLE 0 +#define ONEWIRE_CRC8_TABLE 0 +#endif + +// You can allow 16-bit CRC checks by defining this to 1 +// (Note that ONEWIRE_CRC must also be 1.) +#ifndef ONEWIRE_CRC16 +#define ONEWIRE_CRC16 1 +#endif + +// Platform specific I/O definitions +#define noInterrupts portDISABLE_INTERRUPTS +#define interrupts portENABLE_INTERRUPTS +#define delayMicroseconds sdk_os_delay_us + +#define DIRECT_READ(pin) gpio_read(pin) +#define DIRECT_MODE_INPUT(pin) gpio_enable(pin, GPIO_INPUT) +#define DIRECT_MODE_OUTPUT(pin) gpio_enable(pin, GPIO_OUTPUT) +#define DIRECT_WRITE_LOW(pin) gpio_write(pin, 0) +#define DIRECT_WRITE_HIGH(pin) gpio_write(pin, 1) + + +void onewire_init(uint8_t pin); + +// Perform a 1-Wire reset cycle. Returns 1 if a device responds +// with a presence pulse. Returns 0 if there is no device or the +// bus is shorted or otherwise held low for more than 250uS +uint8_t onewire_reset(uint8_t pin); + +// Issue a 1-Wire rom select command, you do the reset first. +void onewire_select(uint8_t pin, const uint8_t rom[8]); + +// Issue a 1-Wire rom skip command, to address all on bus. +void onewire_skip(uint8_t pin); + +// Write a byte. If 'power' is one then the wire is held high at +// the end for parasitically powered devices. You are responsible +// for eventually depowering it by calling depower() or doing +// another read or write. +void onewire_write(uint8_t pin, uint8_t v, uint8_t power); + +void onewire_write_bytes(uint8_t pin, const uint8_t *buf, uint16_t count, bool power); + +// Read a byte. +uint8_t onewire_read(uint8_t pin); + +void onewire_read_bytes(uint8_t pin, uint8_t *buf, uint16_t count); + +// Write a bit. The bus is always left powered at the end, see +// note in write() about that. +// void onewire_write_bit(uint8_t pin, uint8_t v); + +// Read a bit. +// uint8_t onewire_read_bit(uint8_t pin); + +// Stop forcing power onto the bus. You only need to do this if +// you used the 'power' flag to write() or used a write_bit() call +// and aren't about to do another read or write. You would rather +// not leave this powered if you don't have to, just in case +// someone shorts your bus. +void onewire_depower(uint8_t pin); + +#if ONEWIRE_SEARCH +// Clear the search state so that if will start from the beginning again. +void onewire_reset_search(uint8_t pin); + +// Setup the search to find the device type 'family_code' on the next call +// to search(*newAddr) if it is present. +void onewire_target_search(uint8_t pin, uint8_t family_code); + +// Look for the next device. Returns 1 if a new address has been +// returned. A zero might mean that the bus is shorted, there are +// no devices, or you have already retrieved all of them. It +// might be a good idea to check the CRC to make sure you didn't +// get garbage. The order is deterministic. You will always get +// the same devices in the same order. +uint8_t onewire_search(uint8_t pin, uint8_t *newAddr); +#endif + +#if ONEWIRE_CRC +// Compute a Dallas Semiconductor 8 bit CRC, these are used in the +// ROM and scratchpad registers. +uint8_t onewire_crc8(const uint8_t *addr, uint8_t len); + +#if ONEWIRE_CRC16 +// Compute the 1-Wire CRC16 and compare it against the received CRC. +// Example usage (reading a DS2408): +// // Put everything in a buffer so we can compute the CRC easily. +// uint8_t buf[13]; +// buf[0] = 0xF0; // Read PIO Registers +// buf[1] = 0x88; // LSB address +// buf[2] = 0x00; // MSB address +// WriteBytes(net, buf, 3); // Write 3 cmd bytes +// ReadBytes(net, buf+3, 10); // Read 6 data bytes, 2 0xFF, 2 CRC16 +// if (!CheckCRC16(buf, 11, &buf[11])) { +// // Handle error. +// } +// +// @param input - Array of bytes to checksum. +// @param len - How many bytes to use. +// @param inverted_crc - The two CRC16 bytes in the received data. +// This should just point into the received data, +// *not* at a 16-bit integer. +// @param crc - The crc starting value (optional) +// @return True, iff the CRC matches. +bool onewire_check_crc16(const uint8_t* input, uint16_t len, const uint8_t* inverted_crc, uint16_t crc); + +// Compute a Dallas Semiconductor 16 bit CRC. This is required to check +// the integrity of data received from many 1-Wire devices. Note that the +// CRC computed here is *not* what you'll get from the 1-Wire network, +// for two reasons: +// 1) The CRC is transmitted bitwise inverted. +// 2) Depending on the endian-ness of your processor, the binary +// representation of the two-byte return value may have a different +// byte order than the two bytes you get from 1-Wire. +// @param input - Array of bytes to checksum. +// @param len - How many bytes to use. +// @param crc - The crc starting value (optional) +// @return The CRC16, as defined by Dallas Semiconductor. +uint16_t onewire_crc16(const uint8_t* input, uint16_t len, uint16_t crc); +#endif +#endif + +#endif