diff options
Diffstat (limited to 'src/ds18b20/tm_stm32f4_onewire.c')
| -rw-r--r-- | src/ds18b20/tm_stm32f4_onewire.c | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/src/ds18b20/tm_stm32f4_onewire.c b/src/ds18b20/tm_stm32f4_onewire.c new file mode 100644 index 0000000..f552fa1 --- /dev/null +++ b/src/ds18b20/tm_stm32f4_onewire.c @@ -0,0 +1,411 @@ +/**
+ * |----------------------------------------------------------------------
+ * | Copyright (C) Tilen Majerle, 2014
+ * |
+ * | This program is free software: you can redistribute it and/or modify
+ * | it under the terms of the GNU General Public License as published by
+ * | the Free Software Foundation, either version 3 of the License, or
+ * | any later version.
+ * |
+ * | This program is distributed in the hope that it will be useful,
+ * | but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * | GNU General Public License for more details.
+ * |
+ * | You should have received a copy of the GNU General Public License
+ * | along with this program. If not, see <http://www.gnu.org/licenses/>.
+ * |----------------------------------------------------------------------
+ */
+#include "tm_stm32f4_onewire.h"
+
+static void
+TM_GPIO_SetPinAsInput(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
+{
+ GPIO_SetBits(GPIOx, GPIO_Pin);
+#if 0
+ GPIO_InitTypeDef GPIO_InitStructure;
+ GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
+ GPIO_InitStructure.GPIO_Pin = GPIO_Pin;
+ GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
+ GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
+ GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
+ GPIO_Init(GPIOx, &GPIO_InitStructure);
+#endif
+}
+
+static void
+TM_GPIO_SetPinAsOutput(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
+{
+#if 0
+ GPIO_InitTypeDef GPIO_InitStructure;
+ GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
+ GPIO_InitStructure.GPIO_Pin = GPIO_Pin;
+ GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
+ GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
+ GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
+ GPIO_Init(GPIOx, &GPIO_InitStructure);
+#endif
+}
+
+static int
+TM_GPIO_GetInputPinValue(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
+{
+ return GPIO_ReadInputDataBit(GPIOx, GPIO_Pin) ? 1 : 0;
+}
+
+static void
+ONEWIRE_DELAY(int us)
+{
+ const uint32_t wait_ticks =
+ (uint64_t)us * (uint64_t)SystemCoreClock / (uint64_t)1000000;
+
+ const uint32_t timeout = SysTick->VAL + wait_ticks;
+ while (SysTick->VAL < timeout);
+}
+
+void TM_OneWire_Init(TM_OneWire_t* OneWireStruct, GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin) {
+ ONEWIRE_INPUT(OneWireStruct);
+ /* Save settings */
+ OneWireStruct->GPIOx = GPIOx;
+ OneWireStruct->GPIO_Pin = GPIO_Pin;
+}
+
+uint8_t TM_OneWire_Reset(TM_OneWire_t* OneWireStruct) {
+ uint8_t i;
+
+ /* Line low, and wait 480us */
+ ONEWIRE_LOW(OneWireStruct);
+ ONEWIRE_OUTPUT(OneWireStruct);
+ ONEWIRE_DELAY(480);
+
+ /* Release line and wait for 70us */
+ ONEWIRE_INPUT(OneWireStruct);
+ ONEWIRE_DELAY(70);
+
+ /* Check bit value */
+ i = TM_GPIO_GetInputPinValue(OneWireStruct->GPIOx, OneWireStruct->GPIO_Pin);
+
+ /* Delay for 410 us */
+ ONEWIRE_DELAY(410);
+
+ /* Return value of presence pulse, 0 = OK, 1 = ERROR */
+ return i;
+}
+
+void TM_OneWire_WriteBit(TM_OneWire_t* OneWireStruct, uint8_t bit) {
+ if (bit) {
+ /* Set line low */
+ ONEWIRE_LOW(OneWireStruct);
+ ONEWIRE_OUTPUT(OneWireStruct);
+ ONEWIRE_DELAY(10);
+
+ /* Bit high */
+ ONEWIRE_INPUT(OneWireStruct);
+
+ /* Wait for 55 us and release the line */
+ ONEWIRE_DELAY(55);
+ ONEWIRE_INPUT(OneWireStruct);
+ } else {
+ /* Set line low */
+ ONEWIRE_LOW(OneWireStruct);
+ ONEWIRE_OUTPUT(OneWireStruct);
+ ONEWIRE_DELAY(65);
+
+ /* Bit high */
+ ONEWIRE_INPUT(OneWireStruct);
+
+ /* Wait for 5 us and release the line */
+ ONEWIRE_DELAY(5);
+ ONEWIRE_INPUT(OneWireStruct);
+ }
+
+}
+
+uint8_t TM_OneWire_ReadBit(TM_OneWire_t* OneWireStruct) {
+ uint8_t bit = 0;
+
+ /* Line low */
+ ONEWIRE_LOW(OneWireStruct);
+ ONEWIRE_OUTPUT(OneWireStruct);
+ ONEWIRE_DELAY(3);
+
+ /* Release line */
+ ONEWIRE_INPUT(OneWireStruct);
+ ONEWIRE_DELAY(10);
+
+ /* Read line value */
+ if (TM_GPIO_GetInputPinValue(OneWireStruct->GPIOx, OneWireStruct->GPIO_Pin)) {
+ /* Bit is HIGH */
+ bit = 1;
+ }
+
+ /* Wait 50us to complete 60us period */
+ ONEWIRE_DELAY(50);
+
+ /* Return bit value */
+ return bit;
+}
+
+void TM_OneWire_WriteByte(TM_OneWire_t* OneWireStruct, uint8_t byte) {
+ uint8_t i = 8;
+ /* Write 8 bits */
+ while (i--) {
+ /* LSB bit is first */
+ TM_OneWire_WriteBit(OneWireStruct, byte & 0x01);
+ byte >>= 1;
+ }
+}
+
+uint8_t TM_OneWire_ReadByte(TM_OneWire_t* OneWireStruct) {
+ uint8_t i = 8, byte = 0;
+ while (i--) {
+ byte >>= 1;
+ byte |= (TM_OneWire_ReadBit(OneWireStruct) << 7);
+ }
+
+ return byte;
+}
+
+uint8_t TM_OneWire_First(TM_OneWire_t* OneWireStruct) {
+ /* Reset search values */
+ TM_OneWire_ResetSearch(OneWireStruct);
+
+ /* Start with searching */
+ return TM_OneWire_Search(OneWireStruct, ONEWIRE_CMD_SEARCHROM);
+}
+
+uint8_t TM_OneWire_Next(TM_OneWire_t* OneWireStruct) {
+ /* Leave the search state alone */
+ return TM_OneWire_Search(OneWireStruct, ONEWIRE_CMD_SEARCHROM);
+}
+
+void TM_OneWire_ResetSearch(TM_OneWire_t* OneWireStruct) {
+ /* Reset the search state */
+ OneWireStruct->LastDiscrepancy = 0;
+ OneWireStruct->LastDeviceFlag = 0;
+ OneWireStruct->LastFamilyDiscrepancy = 0;
+}
+
+uint8_t TM_OneWire_Search(TM_OneWire_t* OneWireStruct, uint8_t command) {
+ uint8_t id_bit_number;
+ uint8_t last_zero, rom_byte_number, search_result;
+ uint8_t id_bit, cmp_id_bit;
+ uint8_t 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 (!OneWireStruct->LastDeviceFlag) {
+ // 1-Wire reset
+ if (TM_OneWire_Reset(OneWireStruct)) {
+ /* Reset the search */
+ OneWireStruct->LastDiscrepancy = 0;
+ OneWireStruct->LastDeviceFlag = 0;
+ OneWireStruct->LastFamilyDiscrepancy = 0;
+ return 0;
+ }
+
+ // issue the search command
+ TM_OneWire_WriteByte(OneWireStruct, command);
+
+ // loop to do the search
+ do {
+ // read a bit and its complement
+ id_bit = TM_OneWire_ReadBit(OneWireStruct);
+ cmp_id_bit = TM_OneWire_ReadBit(OneWireStruct);
+
+ // 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 < OneWireStruct->LastDiscrepancy) {
+ search_direction = ((OneWireStruct->ROM_NO[rom_byte_number] & rom_byte_mask) > 0);
+ } else {
+ // if equal to last pick 1, if not then pick 0
+ search_direction = (id_bit_number == OneWireStruct->LastDiscrepancy);
+ }
+
+ // 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) {
+ OneWireStruct->LastFamilyDiscrepancy = last_zero;
+ }
+ }
+ }
+
+ // set or clear the bit in the ROM byte rom_byte_number
+ // with mask rom_byte_mask
+ if (search_direction == 1) {
+ OneWireStruct->ROM_NO[rom_byte_number] |= rom_byte_mask;
+ } else {
+ OneWireStruct->ROM_NO[rom_byte_number] &= ~rom_byte_mask;
+ }
+
+ // serial number search direction write bit
+ TM_OneWire_WriteBit(OneWireStruct, 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) {
+ //docrc8(ROM_NO[rom_byte_number]); // accumulate the CRC
+ 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
+ OneWireStruct->LastDiscrepancy = last_zero;
+
+ // check for last device
+ if (OneWireStruct->LastDiscrepancy == 0) {
+ OneWireStruct->LastDeviceFlag = 1;
+ }
+
+ search_result = 1;
+ }
+ }
+
+ // if no device found then reset counters so next 'search' will be like a first
+ if (!search_result || !OneWireStruct->ROM_NO[0]) {
+ OneWireStruct->LastDiscrepancy = 0;
+ OneWireStruct->LastDeviceFlag = 0;
+ OneWireStruct->LastFamilyDiscrepancy = 0;
+ search_result = 0;
+ }
+
+ return search_result;
+}
+
+int TM_OneWire_Verify(TM_OneWire_t* OneWireStruct) {
+ unsigned char rom_backup[8];
+ int i,rslt,ld_backup,ldf_backup,lfd_backup;
+
+ // keep a backup copy of the current state
+ for (i = 0; i < 8; i++)
+ rom_backup[i] = OneWireStruct->ROM_NO[i];
+ ld_backup = OneWireStruct->LastDiscrepancy;
+ ldf_backup = OneWireStruct->LastDeviceFlag;
+ lfd_backup = OneWireStruct->LastFamilyDiscrepancy;
+
+ // set search to find the same device
+ OneWireStruct->LastDiscrepancy = 64;
+ OneWireStruct->LastDeviceFlag = 0;
+
+ if (TM_OneWire_Search(OneWireStruct, ONEWIRE_CMD_SEARCHROM)) {
+ // check if same device found
+ rslt = 1;
+ for (i = 0; i < 8; i++) {
+ if (rom_backup[i] != OneWireStruct->ROM_NO[i]) {
+ rslt = 1;
+ break;
+ }
+ }
+ } else {
+ rslt = 0;
+ }
+
+ // restore the search state
+ for (i = 0; i < 8; i++) {
+ OneWireStruct->ROM_NO[i] = rom_backup[i];
+ }
+ OneWireStruct->LastDiscrepancy = ld_backup;
+ OneWireStruct->LastDeviceFlag = ldf_backup;
+ OneWireStruct->LastFamilyDiscrepancy = lfd_backup;
+
+ // return the result of the verify
+ return rslt;
+}
+
+void TM_OneWire_TargetSetup(TM_OneWire_t* OneWireStruct, uint8_t family_code) {
+ uint8_t i;
+
+ // set the search state to find SearchFamily type devices
+ OneWireStruct->ROM_NO[0] = family_code;
+ for (i = 1; i < 8; i++) {
+ OneWireStruct->ROM_NO[i] = 0;
+ }
+
+ OneWireStruct->LastDiscrepancy = 64;
+ OneWireStruct->LastFamilyDiscrepancy = 0;
+ OneWireStruct->LastDeviceFlag = 0;
+}
+
+void TM_OneWire_FamilySkipSetup(TM_OneWire_t* OneWireStruct) {
+ // set the Last discrepancy to last family discrepancy
+ OneWireStruct->LastDiscrepancy = OneWireStruct->LastFamilyDiscrepancy;
+ OneWireStruct->LastFamilyDiscrepancy = 0;
+
+ // check for end of list
+ if (OneWireStruct->LastDiscrepancy == 0) {
+ OneWireStruct->LastDeviceFlag = 1;
+ }
+}
+
+uint8_t TM_OneWire_GetROM(TM_OneWire_t* OneWireStruct, uint8_t index) {
+ return OneWireStruct->ROM_NO[index];
+}
+
+void TM_OneWire_Select(TM_OneWire_t* OneWireStruct, uint8_t* addr) {
+ uint8_t i;
+ TM_OneWire_WriteByte(OneWireStruct, ONEWIRE_CMD_MATCHROM);
+
+ for (i = 0; i < 8; i++) {
+ TM_OneWire_WriteByte(OneWireStruct, *(addr + i));
+ }
+}
+
+void TM_OneWire_SelectWithPointer(TM_OneWire_t* OneWireStruct, uint8_t *ROM) {
+ uint8_t i;
+ TM_OneWire_WriteByte(OneWireStruct, ONEWIRE_CMD_MATCHROM);
+
+ for (i = 0; i < 8; i++) {
+ TM_OneWire_WriteByte(OneWireStruct, *(ROM + i));
+ }
+}
+
+void TM_OneWire_GetFullROM(TM_OneWire_t* OneWireStruct, uint8_t *firstIndex) {
+ uint8_t i;
+ for (i = 0; i < 8; i++) {
+ *(firstIndex + i) = OneWireStruct->ROM_NO[i];
+ }
+}
+
+uint8_t TM_OneWire_CRC8(uint8_t *addr, uint8_t len) {
+ uint8_t crc = 0, inbyte, i, mix;
+
+ while (len--) {
+ inbyte = *addr++;
+ for (i = 8; i; i--) {
+ mix = (crc ^ inbyte) & 0x01;
+ crc >>= 1;
+ if (mix) {
+ crc ^= 0x8C;
+ }
+ inbyte >>= 1;
+ }
+ }
+
+ /* Return calculated CRC */
+ return crc;
+}
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