[Energia Library] OneWire DS18B20 (430 & Stellaris)

[manhdan 1]

I use MSP430G2553, in 16MHz it work but in 1Mhz it doesn't work, please fix it.

 

                 

 

 

[manhdan 1]

I found the answer here.

 

Thank you OzGrant, it working very well

[nosk8fx 0]

@@SloMusti, any comment on that error:
test_sensors.ino:28:8: error: 'class DS18B20' has no member named 'InitGPIO'

 

its from that line: ds.InitGPIO();

 

Am I missing something?

 

thanks in advance

[Grandthau 0]

Hi, i am using MSP430F5529 launchpad and DS18S20. I am trying to make it work, but search returns 1. So no devices found. I only get this.

 

G'day StellarisOW
ret=(1) No more addresses.
From array
 

I have checked the connections to make sure they are right.

The data pin is connected to pin P3.6

 

Any help please??

[zeke 693]

I'm not able to run the demo code as parasitic. What should I do to make it working? Thank you

@@hawwwran, I realize that your question is old but I have your answer for you.

 

You can operate the ds18b20 in parasitic mode for all normal interactions except temperature conversions and EEPROM programming. During those operations, parasitic mode requires that you apply a strong pull-up to DQ in order to supply extra energy to the device via the DQ pin.

 

It would seem that these energia libraries expect the device to operate in three wire mode only. That means, wire the device fully with Vcc, DQ and GND.

[zeke 693]

Hi, i am using MSP430F5529 launchpad and DS18S20. I am trying to make it work, but search returns 1. So no devices found. I only get this.

 

G'day StellarisOW

ret=(1) No more addresses.

From array

 

I have checked the connections to make sure they are right.

The data pin is connected to pin P3.6

 

Any help please??

What is your cpu clock speed set to?

Do you have a logic analyzer to inspect the signals?

Did you wire up the sensor in three wire mode?

 

The simplest one-wire test is to do a one-wire reset and see if the device responds with a presence pulse.

[Grandthau 0]

What is your cpu clock speed set to?

Do you have a logic analyzer to inspect the signals?

Did you wire up the sensor in three wire mode?

 

The simplest one-wire test is to do a one-wire reset and see if the device responds with a presence pulse.

 

My cpu speed is 16MHz, and i do not have a logic analyzer, sorry. I am using the three wire mode to wire up the sensor.

If the return is 1, does it mean that the device does not pull down the pulse when a reset happens??

[zeke 693]

@@Grandthau, you said that you put DQ on P3.6.  Have you told the GFDS18B20 library where to find your temperature sensor?

[Grandthau 0]

@@Grandthau, you said that you put DQ on P3.6.  Have you told the GFDS18B20 library where to find your temperature sensor?

I constructed an object of class DS18B20 and gave the pin as a parameter. Do i have to change anything else?

After that i change the family code to 0x10h which is the code for DS18S20 sensors. But the program never reaches this point of course...

[zeke 693]

I am not an energia user so we may have to ask an energia user to pipe up here.

 

In CSS, I would have to setup both the pin number and the port number in C code so that the functions would know where to find the sensor.

 

So, the missing information is how to tell energia what port the sensor is on.

 

Figure that out and it ought to work.

[spirilis 1,265]

The pin# does that. Energia internally has a number of arrays per-board which tell it what port, pin, pxsel, etc corresponds to the "pin#".

 

Sent from my Galaxy Note 10.1

[zeke 693]

What pin number does energia map P3.6 to?

 

I think I just figure it out using pins_energia.h.

static const uint8_t P3_6 = 29;

[spirilis 1,265]

Yep that's it.

 

Sent from my Galaxy Note II with Tapatalk 4

[Gini009 0]

Did any of you guys verify the correctness of the temperature?

 

I am using DS18S20, and while i do get a temperature reading, its a few degrees off.  I am running the same sensor on the raspberry pi and its pretty close to ambient temp. 

 

[zeke 693]

Which sensor are you using?

 

There are two different temperature sensors being discussed in this thread - the DS18B20 and the DS18S20. 

 

The math to compute the temperature is slightly different for each sensor.

 

Concerning accuracy, the Dallas sensor is amazingly accurate. I have never seen one that was as bad as, say, the internal temp sensor of the MSP430 (+/- 2 degrees).