Source code to get DS18B20 temperature feedback in nrf51822

RE: Source code to get DS18B20 temperature feedback in nrf51822

Gaurav — Mon, 07 Jan 2019 11:50:20 GMT

Here we are not checking the CRC check calculated from the scratchpad and the one calculated from rom.

Do we require to do so if yes then how

RE: Source code to get DS18B20 temperature feedback in nrf51822

chianglin — Thu, 06 Sep 2018 14:57:53 GMT

Hi Martin,

My DS18B20 hardware circuit is the same as you.

Let me check if there have any problem of hardware circuit, and then discuss with you.

Thank you for your assistance.

Chianglin

RE: Source code to get DS18B20 temperature feedback in nrf51822

Martin Lesund — Thu, 06 Sep 2018 07:15:58 GMT

Hi Ives,

Before adding new features, can you confirm that you are actually getting out the correct values from your temperature sensor?
Could you also provide schematics on how your DS18b20 circuit is as well? (do you use a pull-up

I got this when testing your application:

Make sure that your circuit is like:

RE: Source code to get DS18B20 temperature feedback in nrf51822

chianglin — Wed, 05 Sep 2018 15:59:28 GMT

Hi Hi Martin,

Yes. you are right.

I had check my DS18b20 circuit again, and had connect to incorrect pin.

After I connect DS18B20 data pin with P0.29, I had print out all the ROM data into RTT, please find the following debug message

According to the display result of the One-Wire waveform, the data read should be 0x0118323C7DFF. However, the data I read is 0xFFFFFFFFFFFF..

My source code is:

devzone.nordicsemi.com/.../DS18B20Test_5F00_03.7z

Would you please tell me how can I modify my code?

Thank you,

Chianglin

RE: Source code to get DS18B20 temperature feedback in nrf51822

Martin Lesund — Wed, 05 Sep 2018 09:31:41 GMT

Hi Ives,

I ran your exact application you posted.

I did not have any issues:

However, if i disconnect VDD to the sensor or the one wire data line I get stuck:

Could you post how you have connected to the Sensor?

(RED- VDD, Yellow-onewire(p0.29), BLACK-GND)

RE: Source code to get DS18B20 temperature feedback in nrf51822

chianglin — Wed, 05 Sep 2018 09:16:46 GMT

Hi Martin,

Sorry, I forgot to tell you:

I had already change DS18B20 data pin to pin 29, so I can find follow message.

But the program can not exit following loop.

			while (! iBSPACMonewireReadBit_ni()) {
				NRF_LOG_INFO("(R0004) \r\n");
			}

Thank you,

Chianglin

RE: Source code to get DS18B20 temperature feedback in nrf51822

Martin Lesund — Wed, 05 Sep 2018 07:55:24 GMT

Hi Ives,

Note that I have changed the GPIO pin for the one wire.

#define ONEWIRE_PIN 29

If you have not connected to the pin correctly as well as powering the Temp. sensor you would get out that info message according to my observations.

Please double check and verify the connection.

Best Regards,

Martin L.

RE: Source code to get DS18B20 temperature feedback in nrf51822

chianglin — Tue, 04 Sep 2018 15:57:35 GMT

Hi Martin,

After I will test directly with the code you provided.test directly with the code you provided, and it still have one problem.

devzone.nordicsemi.com/.../DS18B20Test_5F00_02.7z

It will always print "INFO: (R0004)" in RTT debug windows. It means the program always stay in following loop\

			while (! iBSPACMonewireReadBit_ni()) {
				NRF_LOG_INFO("(R0004) \r\n");
			}

Does I miss something?

Thank you

Chianglin

RE: Source code to get DS18B20 temperature feedback in nrf51822

Martin Lesund — Tue, 04 Sep 2018 15:01:35 GMT

Hi Ives.

I added the full project which I have modified so it now writes out the correct values.
devzone.nordicsemi.com/.../DS18B20TEST.7z

I stripped down main.c and added some stuff in the DS18B20.c so it only takes the measurements of the one-wire sensor. (I used RTT for logging)

(note: 190 = 19.0 C and 662 = 66.2 F)

which is correct:

RE: Source code to get DS18B20 temperature feedback in nrf51822

chianglin — Mon, 03 Sep 2018 14:55:53 GMT

Hi Martin,

My SDK is nRF5_SDK_12.3.0_d7731ad and I am use nrf51822 MCU.

`Please find the attach file for my full project. Please un-compress the 7z file into ./example/peripheral directory.

devzone.nordicsemi.com/.../DS18B20Test.7z

Thank you,

Chianglin

RE: Source code to get DS18B20 temperature feedback in nrf51822

Martin Lesund — Mon, 03 Sep 2018 13:23:19 GMT

Hi Ives,

What SDK version are you running on?
could you send over the whole project so I could recreate it on my desk?

RE: Source code to get DS18B20 temperature feedback in nrf51822

chianglin — Sat, 01 Sep 2018 10:06:09 GMT

Hi Martin,

Thank you for your answer.

I had modify the demo code, and the debug output is:

Power supply: external
Serial got -1:
Got 40959 dCel, 74046 d[Fahr]
Got 40959 dCel, 74046 d[Fahr]
Got 40959 dCel, 74046 d[Fahr]
Got 40959 dCel, 74046 d[Fahr]

About my source code, please find following code:

#include "nrf_gpio.h"
#include "nrf_delay.h"
#include <stdio.h>

/** Structure holding a 1-wire serial number. */
typedef struct sBSPACMonewireSerialNumber
{
	/** The serial number in order MSB to LSB */
	uint8_t id[6];
} sBSPACMonewireSerialNumber;

enum
{
	BSPACM_ONEWIRE_CMD_READ_ROM = 0x33,						/** Read 64-bit ROM code without using search procedure */
	BSPACM_ONEWIRE_CMD_SKIP_ROM = 0xcc,						/** Skip ROM sends the following command to all bus devices */
	BSPACM_ONEWIRE_CMD_READ_POWER_SUPPLY = 0xb4,			// Determine whether device is parasite-powered or external-powered */
	BSPACM_ONEWIRE_CMD_RECALL_EE = 0xb8,					/** Store data from EEPROM into RAM */
	BSPACM_ONEWIRE_CMD_READ_SCRATCHPAD = 0xbe,				/** Read the RAM area. */

	BSPACM_ONEWIRE_CMD_CONVERT_T = 0x44,					// Initiate a temperature conversion.
															/* * Be aware that temperature conversion can take up to 750ms at the
	 														* default 12-bit resolution.
	 														*
	 														* For an externally (non-parasite) powered sensor, the caller may
	 														* use #iBSPACMonewireReadBit_ni to determine whether the conversion
	 														* has completed.	Completion is indicated when the device responds
	 														* with a 1. */
};

/** Define protocol state times in microseconds.
 *
 * @note Since all these times are far less than any sane watchdog
 * interval, and the timing can be important, BSPACM_CORE_DELAY_CYCLES
 * is not used in this module. */
enum
{
	OWT_RSTL_us = 480,						/** Minimum time to hold bus low to ensure reset */
	OWT_RSTH_us = 480,						/** Time to wait for presence detection after reset to quiesce */
	OWT_PDHIGH_us = 60,						/** Delay before presence pulse is known to be valid (15us..60us) */
	OWT_LOW0_us = 60,						/** Minimum time to hold bus low when writing a zero */
	OWT_LOW1_us = 1,						/** Minimum time to hold bus low when writing a one */
	OWT_REC_us = 1,							/** Recovery delay between write/read transaction cycles */
	OWT_INT_us = 1,							/** Time to hold bus low when initiating a read slot */
	OWT_RDV_us = 15 - OWT_INT_us,			/** Point at which read value should be sampled */
	OWT_SLOT_us = 60,						/** Minimum duration of a read or write slot */
};

#ifndef ONEWIRE_PIN
#define ONEWIRE_PIN 26
#endif /* ONEWIRE_PIN */
#define ONEWIRE_BIT (1ULL << ONEWIRE_PIN)

void dirset (void)
{
	NRF_GPIO->DIRSET = ONEWIRE_BIT;
}

void dirclr (void)
{
	NRF_GPIO->PIN_CNF[ONEWIRE_PIN] = 0
		| (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
		| (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
		| (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
		| (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
		| (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos);
}

int iBSPACMonewireReset_ni (void)
{
	int present;

#if 1
	/* Non-standard: Hold bus high for OWT_RESET_us.	This provides
	 * enough parasitic power for the device to signal presence.
	 * Without this, effective RSTL duration may exceed the maximum
	 * 960us before device reset. */
	dirset();
	NRF_GPIO->OUTSET = ONEWIRE_BIT;
	nrf_delay_us(OWT_RSTH_us);

	/* Hold bus low for OWT_RESET_us */
	NRF_GPIO->OUTCLR = ONEWIRE_BIT;
	nrf_delay_us(OWT_RSTL_us);

	/* Release bus and switch to input until presence pulse should be
	 * visible. */
	dirclr();
	nrf_delay_us(OWT_PDHIGH_us);

	/* Record presence if bus is low (DS182x is holding it there) */
	present = !(NRF_GPIO->IN & ONEWIRE_BIT);

	/* Wait for reset cycle to complete */
	nrf_delay_us(OWT_RSTH_us - OWT_PDHIGH_us);
#else
	/* Non-standard: Hold bus high for OWT_RESET_us.	This provides
	 * enough parasitic power for the device to signal presence.
	 * Without this, effective RSTL duration may exceed the maximum
	 * 960us before device reset. */
	nrf_gpio_cfg_output(ONEWIRE_PIN);
	nrf_gpio_pin_set(ONEWIRE_PIN);
	nrf_delay_us(OWT_RSTH_us);

	/* Hold bus low for OWT_RESET_us */
	nrf_gpio_pin_clear(ONEWIRE_PIN);
	nrf_delay_us(OWT_RSTL_us);

	nrf_gpio_cfg_input(ONEWIRE_PIN, NRF_GPIO_PIN_NOPULL);			// Release bus and switch to input until presence pulse should be visible.
	nrf_delay_us(OWT_PDHIGH_us);

	/* Record presence if bus is low (DS182x is holding it there) */
	present = !(nrf_gpio_pin_read(ONEWIRE_PIN));
#endif
	/* Wait for reset cycle to complete */
	nrf_delay_us(OWT_RSTH_us - OWT_PDHIGH_us);

	return present;
}

void vBSPACMonewireShutdown_ni (void)
{
	NRF_GPIO->OUTCLR = ONEWIRE_BIT;
	dirclr();
}

void vBSPACMonewireWriteByte_ni (int byte)
{
	int bp;

	for (bp = 0; bp < 8; ++bp)
	{
		NRF_GPIO->OUTCLR = ONEWIRE_BIT;
		dirset();
		if (byte & 0x01) {
			nrf_delay_us(OWT_LOW1_us);
			dirclr();
			nrf_delay_us(OWT_SLOT_us - OWT_LOW1_us + OWT_REC_us);
		} else {
			nrf_delay_us(OWT_LOW0_us);
			dirclr();
			nrf_delay_us(OWT_SLOT_us - OWT_LOW0_us + OWT_REC_us);
		}
		byte >>= 1;
	}
}

int iBSPACMonewireReadBit_ni (void)
{
	int rv;

	NRF_GPIO->OUTCLR = ONEWIRE_BIT;
	dirset();
	nrf_delay_us(OWT_INT_us);
	dirclr();
	nrf_delay_us(OWT_RDV_us);
	//abc	vBSPACMledSet(0, 1);
	rv = !!(NRF_GPIO->IN & ONEWIRE_BIT);
	//abc	vBSPACMledSet(0, 0);
	nrf_delay_us(OWT_SLOT_us - OWT_RDV_us - OWT_INT_us + OWT_REC_us);
	return rv;
}

int iBSPACMonewireReadByte_ni (void)
{
	int byte = 0;
	int bit = 1;

	do {
		if (iBSPACMonewireReadBit_ni()) {
			byte |= bit;
		}
		bit <<= 1;
	} while (0x100 != bit);
	return byte;
}

int iBSPACMonewireComputeCRC(const unsigned char * romp, int len)
{
	static const unsigned char OW_CRC_POLY = 0x8c;
	unsigned char crc = 0;

	while (0 < len--) {
		int bi;

		crc ^= *romp++;
		for (bi = 0; bi < 8; ++bi) {
			if (crc & 1) {
				crc = (crc >> 1) ^ OW_CRC_POLY;
			} else {
				crc >>= 1;
			}
		}
	}
	return crc;
}

int iBSPACMonewireReadSerialNumber (sBSPACMonewireSerialNumber * snp)
{
	uint8_t rom[8];
	int i;
	int rv = -1;

	do {
		if (! iBSPACMonewireReset_ni()) {
			break;
		}
		vBSPACMonewireWriteByte_ni(BSPACM_ONEWIRE_CMD_READ_ROM);
		for (i = 0; i < sizeof(rom); ++i) {
			rom[i] = iBSPACMonewireReadByte_ni();
		}
		rv = 0;
	} while (0);

	if (0 == rv) {
		if (0 != iBSPACMonewireComputeCRC(rom, sizeof(rom))) {
			rv = -1;
		} else {
			for (i = 0; i < sizeof(snp->id); ++i) {
				snp->id[i] = rom[sizeof(rom) - 2 - i];
			}
		}
	}
	return rv;
}

int iBSPACMonewireRequestTemperature_ni (void)
{
	if (! iBSPACMonewireReset_ni()) {
		return -1;
	}
	vBSPACMonewireWriteByte_ni(BSPACM_ONEWIRE_CMD_SKIP_ROM);
	vBSPACMonewireWriteByte_ni(BSPACM_ONEWIRE_CMD_CONVERT_T);
	return 0;
}

int iBSPACMonewireReadPowerSupply (void)
{
	int rv = -1;

	if (iBSPACMonewireReset_ni())
	{
		vBSPACMonewireWriteByte_ni(BSPACM_ONEWIRE_CMD_SKIP_ROM);
		vBSPACMonewireWriteByte_ni(BSPACM_ONEWIRE_CMD_READ_POWER_SUPPLY);
		rv = iBSPACMonewireReadBit_ni();
	}
	return rv;
}

int iBSPACMonewireReadTemperature_ni (int * temp_xCel)
{
	int t;

	if (! iBSPACMonewireReset_ni()) {
		return -1;
	}
	vBSPACMonewireWriteByte_ni(BSPACM_ONEWIRE_CMD_SKIP_ROM);
	vBSPACMonewireWriteByte_ni(BSPACM_ONEWIRE_CMD_READ_SCRATCHPAD);
	t = iBSPACMonewireReadByte_ni();
	t |= (iBSPACMonewireReadByte_ni() << 8);
	*temp_xCel = t;
	return 0;
}

void DS18B20_Run(void)
{
	do
	{
		if (! iBSPACMonewireReset_ni()) {
			printf("ERR: No DS18B20 present on P0.%u\n", ONEWIRE_PIN);
			break;
		}

		static const char * const supply_type[] = { "parasitic", "external" };

		int external_power = iBSPACMonewireReadPowerSupply();
		printf("Power supply: %s\r\n", supply_type[external_power]);
		if (0 > external_power) {
			printf("ERROR: Device not present?\r\n");
			break;
		}

		sBSPACMonewireSerialNumber serial;
		int rc = iBSPACMonewireReadSerialNumber(&serial);
		printf("Serial got %d: \r\n", rc);
		//abc	vBSPACMconsoleDisplayOctets(serial.id, sizeof(serial.id));
		//abc	putchar('\n');
#if 1
		while (0 == iBSPACMonewireRequestTemperature_ni())
		{
			int t_raw;
			nrf_delay_ms(600UL);
			while (! iBSPACMonewireReadBit_ni()) {
			}
			rc = iBSPACMonewireReadTemperature_ni(&t_raw);
			int t_dCel = (10 * t_raw) / 16;
			int t_dFahr = 320 + (9 * t_dCel) / 5;
			printf("Got %d dCel, %d d[Fahr]\r\n", t_dCel, t_dFahr);
		}
#endif
	} while (0);
	dirset();
	NRF_GPIO->OUTCLR = ONEWIRE_BIT;

}

Would you please tell me how can I modify my code?

Thank you

RE: Source code to get DS18B20 temperature feedback in nrf51822

Martin Lesund — Fri, 31 Aug 2018 13:01:33 GMT

Hi Ives,

Please check out this thread.