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VTI SCP1000 Pressure Sensor — Parallax Forums

VTI SCP1000 Pressure Sensor

JaimeJaime Posts: 16
edited 2011-03-10 15:32 in BASIC Stamp
Do any of you already have the code to interface this sensor to the BS2 (Basic Stamp).. I know theres a lot of material to interface this sensor to the the Propeller but for the Basic Stamp I have not seen nothing yet.. If somebody has a piece of code , along with the schematics to connect the voltage level translator (3.3V->5V, since this sensor works with 3.3V) which really works would be greately appreciated.


Thanks a lot for your feedback

microwaveteach@hotmail.com

Comments

  • allanlane5allanlane5 Posts: 3,815
    edited 2010-04-30 17:52
    Um, what sensor would that be? Oh, you mean the sensor in the title?

    It says it supports the "SPI" protocol -- which on the BS2 is implemented as "SHIFTOUT/SHIFTIN", if that helps.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2010-05-04 18:03
    I believe our Tech Support Dept. has a reference to someone who wrote some code for the VTI 1000, and you'd need a buffer chip such as the 74LVC244A that we carry in order to interface to it from a BASIC Stamp Module. I hope this helps. Take care.

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    Chris Savage

    Parallax Engineering
    ·
  • JDJD Posts: 570
    edited 2010-05-05 22:21
    Gents,

    ·· The sample code available is for the Propeller (spin) only; the BASIC Stamp code has been tested with resistors as apposed to using the buffer IC·chip, which seemed to work decently (minus some formatting issue), The temperature stated 775 °C as apposed to 77.5 °C but the Pascal’s were not correct by a good margin; so there was not an official release of the sample code until we could get it to work correctly.

    As time is always a valuable commodity, here is the code that we found online. Again; this is not a Parallax code, but from a Paul Hopkins; so thank you Paul for providing a template to work from. As time permits, we will verify the code; but for now here is what is available; perhaps someone can isolate the programming error. If so, please contact me at support@parallax.com (ATTN: JD) so I can verify and reward if possible.

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    Respectfully,


    Joshua Donelson
    www.parallax.com
    bs2
    bs2
    SCP1000_test_baro.bs2
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  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2010-05-06 00:17
    And just to clarify, while resistors may have been used in testing, according to the manufacturer of the XBee modules, resistors are not sufficient protection for interfacing to 5V lines. The 74LVC244A or some other translator/buffer chip must be used or you will damage your XBee radio.

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    Chris Savage

    Parallax Engineering
    ·
  • JaimeJaime Posts: 16
    edited 2010-05-06 18:21
    I appreciate your valuable help guys, I will be looking forward for more forthcoming attractions about this interesting project. I understand your effort.

    microwaveteach@hotmail.com
  • bmperreabmperrea Posts: 4
    edited 2011-02-21 08:52
    Hello,

    I embarked on the project of running the SCP1000 on my basic stamp board (of education). I followed the setup of some of the earlier posts and used 1kOhm resistors between the data pins and the board (as in the attached figure). However, more importantly I used an LM2937ET 3.3 Voltage regulator so that my input voltage was approx. 3.3V.

    I got some basic stamp code from one of the earlier posts that was misinterpreted to read incorrect pressures and had the temperature reading in deci-degrees Celcius. I have since edited this code to display Pa, C, and Farenheit (however the interpretation of the pressure was not easy since the number is too big for the largest data type in basic stamp 2 - the word). Note that I also removed some things that were not used so that I didn't fill the EEPROM. If you run into this trouble wait for my post coming next week with my reduced code that puts all of this on a data logger in real time.

    Good luck everyone,

    Brent
    bmperrea@cord.edu diagram.jpg
    bs2
    bs2
    SCP1000_test_baro2.bs2
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    diagram.jpg
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  • bmperreabmperrea Posts: 4
    edited 2011-03-09 14:38
    So, as I said, I've finished my code that puts it all together. It should be well documented but feel free to contact me if you have other ideas/questions. I plan on flying it in a balloon myself in the next month. There's even a picture for how I wired it.

    Note that for this to even run you either need the same data logger or you need to get rid of the code that deals with the data logger since otherwise it will never synchronize.

    Good luck,

    Brent
    Schematic.jpg
    1024 x 606 - 102K
    bsp
    bsp
    Pressure-DataLogger-Timechip.bsp
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  • bmperreabmperrea Posts: 4
    edited 2011-03-10 15:11
    Hey kids. I realized, after a freezer test, that the temperature didn't read out correctly when it was below freezing. That's fixed in this one.

    Brent
    bsp
    bsp
    Pressure-DataLogger-Timechip.bsp
    24K
  • PublisonPublison Posts: 12,366
    edited 2011-03-10 15:32
    Brent, Thanks for the code and schematics. I have one of the sensors working on a propeller, but I want to try it on the Basic Stamp.

    Thank You.
    bmperrea wrote: »
    Hey kids. I realized, after a freezer test, that the temperature didn't read out correctly when it was below freezing. That's fixed in this one.

    Brent
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