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tsl230 sensor and pulsin command — Parallax Forums

tsl230 sensor and pulsin command

ArchiverArchiver Posts: 46,084
edited 2004-01-20 04:09 in General Discussion
Hello,
I am using a tsl230 light to frequency sensor fro taosinc.com. I
followed the project for using a BSII to measure light frequency.
Instead of using the count command, I used code similar to
experiment #18 in the stampworks documentation. I used pulsin. My
questions are:
1.) I used a red led to illuminate the sensor with a black tube to
protect from stray light. I used all settings in combination and the
frequency measurement doesn't add up. The red led is 640nm and the
speed of light I used is 3 X 10^8. For the formula f=c/Wavelength.
Red LED 640 nm wavelength from 5 cm distance


S0 S1 S2 S3 Freq(Hz)Period (uSec)
H H H L 62500 8
H H L L 62500 8
H H L H 10860 48
H H H H 1050 476
L H H L 5310 94
L H L L 10860 46
L H L H 1050 472
L H H H 100 4740

Am I doing something wrong? BTW in the code in Experiment #18,
freq = 50000 / period * 20 is this suppose to be *20 or *10.
Because on the next page of the experiment is:

This creates a problem for BASIC Stamp math though, as it can only
deal with 16-bit numbers
(maximum value is 65,535). To fix the formula, we convert 500,000 to
50,000 x 10 and rewrite the
formula like this
frequency = 50,000 / period * 10
Thanks,
Curtis

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2004-01-20 03:27
    The frequecny output of that sensor is related to light intesity, not
    wavelength.

    -- Jon Williams
    -- Applications Engineer, Parallax
    -- Dallas Office


    Original Message
    From: cenlasoft [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Mf1aP_TWse8eOQm_qsra9Yt5yLHHDsF54TFMVKlAKZzIJyq9cGCoGcdNpGfitKvIW_DKBjT-kQNLQ7R_j9E]cenlasoft@y...[/url
    Sent: Monday, January 19, 2004 9:11 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] tsl230 sensor and pulsin command


    Hello,
    I am using a tsl230 light to frequency sensor fro taosinc.com. I
    followed the project for using a BSII to measure light frequency.
    Instead of using the count command, I used code similar to
    experiment #18 in the stampworks documentation. I used pulsin. My
    questions are:
    1.) I used a red led to illuminate the sensor with a black tube to
    protect from stray light. I used all settings in combination and the
    frequency measurement doesn't add up. The red led is 640nm and the
    speed of light I used is 3 X 10^8. For the formula f=c/Wavelength.
    Red LED 640 nm wavelength from 5 cm distance


    S0 S1 S2 S3 Freq(Hz)Period (uSec)
    H H H L 62500 8
    H H L L 62500 8
    H H L H 10860 48
    H H H H 1050 476
    L H H L 5310 94
    L H L L 10860 46
    L H L H 1050 472
    L H H H 100 4740

    Am I doing something wrong? BTW in the code in Experiment #18,
    freq = 50000 / period * 20 is this suppose to be *20 or *10. Because on
    the next page of the experiment is:

    This creates a problem for BASIC Stamp math though, as it can only
    deal with 16-bit numbers
    (maximum value is 65,535). To fix the formula, we convert 500,000 to
    50,000 x 10 and rewrite the
    formula like this
    frequency = 50,000 / period * 10
    Thanks,
    Curtis
  • ArchiverArchiver Posts: 46,084
    edited 2004-01-20 03:47
    So what you mean is that when they say the sensor
    outputs frequency it is really measuring intensity.
    Then why would I use this sensor for? Are there
    examples? Iam sorry for the many questions.
    Thanks
    Curtis


    --- Jon Williams <jwilliams@p...> wrote:
    > The frequecny output of that sensor is related to
    > light intesity, not
    > wavelength.
    >
    > -- Jon Williams
    > -- Applications Engineer, Parallax
    > -- Dallas Office
    >
    >
    >
    Original Message
    > From: cenlasoft [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=uKOgAwBEz2JTjAst0sb3aHW_3SFg8CofhknqcWqrnubLDMubIow5Y_Nt85NUJPv45zzL5MZItj1w]cenlasoft@y...[/url
    > Sent: Monday, January 19, 2004 9:11 PM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] tsl230 sensor and pulsin
    > command
    >
    >
    > Hello,
    > I am using a tsl230 light to frequency sensor fro
    > taosinc.com. I
    > followed the project for using a BSII to measure
    > light frequency.
    > Instead of using the count command, I used code
    > similar to
    > experiment #18 in the stampworks documentation. I
    > used pulsin. My
    > questions are:
    > 1.) I used a red led to illuminate the sensor with a
    > black tube to
    > protect from stray light. I used all settings in
    > combination and the
    > frequency measurement doesn't add up. The red led is
    > 640nm and the
    > speed of light I used is 3 X 10^8. For the formula
    > f=c/Wavelength.
    > Red LED 640 nm wavelength from 5 cm distance
    >
    >
    > S0 S1 S2 S3 Freq(Hz)Period (uSec)
    > H H H L 62500 8
    > H H L L 62500 8
    > H H L H 10860 48
    > H H H H 1050 476
    > L H H L 5310 94
    > L H L L 10860 46
    > L H L H 1050 472
    > L H H H 100 4740
    >
    > Am I doing something wrong? BTW in the code in
    > Experiment #18,
    > freq = 50000 / period * 20 is this suppose to be *20
    > or *10. Because on
    > the next page of the experiment is:
    >
    > This creates a problem for BASIC Stamp math though,
    > as it can only
    > deal with 16-bit numbers
    > (maximum value is 65,535). To fix the formula, we
    > convert 500,000 to
    > 50,000 x 10 and rewrite the
    > formula like this
    > frequency = 50,000 / period * 10
    > Thanks,
    > Curtis
    >
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  • ArchiverArchiver Posts: 46,084
    edited 2004-01-20 04:09
    Yes, it measures intensity. The ability to select filters lets you
    identify color, like I did with my little M&M color ID project:

    http://www.parallax.com/dl/docs/cols/nv/vol4/col/98.pdf

    -- Jon Williams
    -- Applications Engineer, Parallax
    -- Dallas Office


    Original Message
    From: Curtis Desselles [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=DKPBc-EZQ_4dWVw_Ak9mvrVADTCng_1yWUmFbXhoPbdq9HVFfmv_HOxUnJFjIi-YMhA5XCF3O0oCEELOxg]cenlasoft@y...[/url
    Sent: Monday, January 19, 2004 9:47 PM
    To: basicstamps@yahoogroups.com
    Subject: RE: [noparse][[/noparse]basicstamps] tsl230 sensor and pulsin command


    So what you mean is that when they say the sensor
    outputs frequency it is really measuring intensity.
    Then why would I use this sensor for? Are there
    examples? Iam sorry for the many questions.
    Thanks
    Curtis
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