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  • Author Author: dwinhold
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Safe and Sound : Winter/cold weather survival suit Post #10 (Help needed and an update)

dwinhold

I'm not sure how much of an update this is considered. I am having issues with the temperature sensors (DS18B20 Temperature Sensors) which are OneWire. Now the issue is that they don't work on the MSP432P401R. I have tried everything in the past 2 weeks and a lot of different coding to no avail. I copied and pasted code and even used the code in Energia for the OneWire temperature sensors and nothing worked. I found some information on line saying all the coding for the sensor works on the MSP430. When I used the sample code and compiled it for the MSP430 it worked, but it crashes for the MSP432. Since this is what I require to finish my project I require help on finding the correct sensors. I have the suit complete with the heat elements sewn in. The power supply is ready and wires are run throughout the suit, I just need working sensors.

 

A quick update on the waterproofing of the board with the acrylic conformal coating. I filled a tray with water and added salt (quite a bit of salt), powered up the test Arduino and set it into the salt water for 2 hours. (I kept the plugged-in end out of the water). I then took it out and let it dry off (It kept working and I didn't wash it off). A week later (2 days ago) I plugged it in and it is still working so I put it into another tray full of salt water for 1 more hour (It still is working). I did wash it off with clean water and it is no worse for wear, I am very impressed with the coating, giving me different use ideas for the future.

 

So, I require any help or advice available

 

My question to everyone, what temperature sensors work on the MSP432? Since I already spent money on sensors that don't work, I need to get the correct ones (Quickly).

 

Thank you for any help you can give

 

Dale Winhold

  • Hi Dale,

     

    it seems that the 1-Wire temperature sensors (and other sensors) interfacing with the MSP320 reports some well-known issues. This is one of many links I have found about this problem: https://github.com/energia/Energia/issues/65 and it seems that it is a sort of problem in the Energia IDE. Take in account that also in past with MSP 430 when I road tested I have found many crap libraries, some working bad and so on. I have not the possibility to test it directly here but it sounds not so strange to me that there are problems.

    Related to your specific problem with the temperature sensor it seems that this guide can be helpful to you: http://karve.in/?p=1408 as well as this other link 1-Wire and MSP430 | welcome to the world of... with special attention on a more detailed software examples.

    As it seems a bug in the 1-Wire library this link can also be useful: https://www.pjrc.com/teensy/td_libs_OneWire.html seems a version of the library full working.

     

    Let me know what happens and if the problem persists I will try to investigate more in depth. The sources you are using are those published in the previous posts ?

     

    Enrico

  • ... logging a help request on the e2e.ti forum, under MSP342 area, also often helps. Certainly when you make clear that you are a beginner and that you're participating in this design challenge.

  • Can you post the code that works on the MSP430 and crashes on the MSP432? More eyes can have a look at it then.

    I don't have the DS18B20 but there should be no reason why the MSP432 would be unable to use it.

    Where does your code crash?

  • I can imagine the frustration...

    Are you using a separate power wire to the DS18B20 (it may be a bit safer to use 3 wires than just 2)

    Presumably you are using a 4.7K pull-up.

    Have you tried adapting arduino code to work with energia? Maybe it would work better than the energia code.

    One thing to check is if the signal pin is assigned correctly - energia uses a different convention than the way most launchpads are numbered.

    I just had to re-document it as I was confused. I'll post the energia pinouts for this launchpad if I can get a blog out tomorrow.

    It would be useful to look at the pin with a scope to see if it is being controlled by the MCU, and if the device responds.

    I don't know much about these devices, but presumably you need to be accurate with their 64 bit address, so the discovery phase and sequence is important.

    Another thing to check is how the code does the serial timing - presumably it is bit-banging, but maybe they were careless with the code and the faster speed of the 432 messes up the serial rate.