This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TIDA-00489: TIDA-00489

Part Number: TIDA-00489
Other Parts Discussed in Thread: TIDA-01398, OPT3001, OPT3002, TIDA-010027, BOOSTXL-TLV8544PIR, CC2650

Hello TI team support

I need your help with PIR design.

I would like develop a motion detector (PIR) that based on one of your references design - TIDA-00489 or TIDA-01398 or other that i don't found :)

I need detect with that PIR a small animals - mice or lizards, that's the size, plus minus . after that i will turn ON a camera with white or infrared LEDs in order to take a photo. All that will work from battery source.

Now i need your professional suggestion:

I found many suggestions/reference design in your website, which one is a best one to my application - Immune to the lighting that I mentioned, identifying small animals, very low power consummation.

Please suggest

best regards

ilya

 

  • Hello,

    There are a few things to consider for this application.

    First, what is the range of detection needed and the field of view?  These are very small signatures compared to the size of humans or typical pets from which motion tends to be easily picked up by PIR sensors.  Depending on the range needed, more signal gain may be needed at the expense of increased noise.  Limiting the field of view by using different Fresnel lenses will also help.

    Secondly, is this application intended for indoors or outdoors use case?  If this is intended for outdoors, then some sort of temperature compensation will be needed that these reference designs do not include.  As the temperature of the target approaches the background (ambient) temperature, the signal due to motion of the target is reduced due to the smaller delta in temperature.  This will be especially more difficult when sensing motion of reptiles.  The range and field of view may need to be reduced for outdoor use compared to indoors.

    Lighting can cause false triggers in PIR's especially when the light source is in the field of view as the light source will also be seen as a heat source which changes compared to a static background when turned on/off.  In this application, since the light source will likely be in the same enclosure as the PIR, this may not be a problem unless the light sources are placed in close thermal proximity to the sensor itself.  One firmware workaround for this type of application is to put the PIR activated camera and light source on a timer and then have a wait period to allow the PIR to settle after the camera and light source are turned off before new motion can turn the camera and light source on again.  For false triggers due to external light sources, the PIR can be coupled with an ambient light sensor such as the OPT3001 or OPT3002 which can be used as a gate to filter the errant PIR pulses due to changes in lighting conditions.

    Any of the PIR reference designs should be able to be modified to fit this application.  Please be aware that sense the reference designs were targeted for building automation, the assumed target for motion detectors are humans.  In certain cases pets (ie., dogs and cats) are also detected but only to be eliminated as false triggers in looking for human motion.  The TIDA-00489 will offer the lowest power consumption.  Reference design TIDA-010027 offers more information with respect to lowering the noise for higher gain and shorter settling times.

    Regards,

    David

  • Hello David

    Thank you very much for clear explanation, your comments very help me to understand the risks in the project !!! this is first time that i am design PIR and especially  a mouse-sized animal.

    Can be situation - that device can be placed in attic or under the roof, i think can be there high ambient temperature.

    • field of view -  wide lens with more than 140 degrees, this is a requirements.
    • range of detection - up to 6m.

    Regarding lighting that can cause a false triggers in PIR's -I will manage this activity, while i will turn ON the light, i will ignore to PIR detection.- thank you again that you pay my attention for light issues.

     - now i need your professional suggestion - with that requirements can i build PIR , hope YES,  if not what is a restrictions.

    I found in the WEB that you sell EVB --> BOOSTXL-TLV8544PIR, first of all i will create POC (Proof of Concept ) with that EVB.

    Please help me, what a adjustment i need mike on that EVB in order to be complacence to my requirements with adding a temperature compensation.

    With best regards

    Ilya

  • Hi Ilya,

    Yes, I think its possible for PIR to meet your requirements.  It will certainly be the technology which offers the lowest power dissipation.  The uncertainty will come due to the small size of the target and the environment as I explained previously.

    For temperature compensation, there a couple of different ways it can be implemented on the BOOSTXL-TLV8544PIR with the CC2650 LaunchPad.  First, referring to the schematic on page 22 of the booster pack user's guide, you can add a silicon diode in series with R11 and a second silicon diode in series with R18.  Without changing the resistor values, this modification will widen the window comparison and reduce sensitivity.  Reducing the value of R11 and R18 to compensate for the additional diode voltage drops will restore the original window size while adding temperature dependence due to the presence of the diodes.  The second way would be through firmware.  Since the output of the second amplifier stage goes to the CC2650 ADC and because the CC2650 has a temperature sensor built in, the comparator thresholds and their temperature compensation can be handled in the digital domain without any hardware modification.

    As discussed in the TIDA-00489 and TIDA-01398 user's guides, the gain on the amplifier stages for the booster pack is very close to maximum without causing stability issues.  If it is discovered that more sensitivity is needed for this application, an easy way to increase the sensitivity would be to increase the sensor bias at the expense of increased power dissipation and without modifying the gain of the signal path.  This is accomplished by reducing the value of R16 and R12.

    Lastly, if you see that fast motion of the targets is being missed, you may need to shift the passband of the filter to correct.  This is also discussed in the TIDA-00489 user's guide.

    Before making any of the changes above, I recommend using the booster pack as-is without modifications in order to determine exactly what needs to be altered. That will prevent making changes which may be unnecessary and save some time.

    Good Luck!

    Regards,

    David

  • Hi David
    Thank you for a clear explanation.
    A.

    You say that i need add a silicon diode in series with R11 and R18. In order to prevent misunderstood:

    1. that diodes have polarity, cathode have direction to GND, see attached file (Please confirm)

    2. can you please suggest part number of diodes (maybe it should have a special requirements: Capacitance, Vf etc.. Or it can be as D4 and D5 (1N4148X-TP) as referring on the schematic on page 22 ?

    3. Sorry, but i not understand the use case of these diodes. I would like learn from professionals FAE like you :), can you please explain use of it to me.

    B.

    1. i not understand the used of microelectronic temperature sensor. the gain and level of comperators - U1C and U1D is fix and insert to uC as interrupt. How can play with comparators thresholds and their temperature compensation with digital domain without any hardware modification?

    Best regards

    Ilya

  • Ilya,

    Your previous post asked about temperature compensation because of the high ambient temperature environment.  Adding the two diodes or using the internal temperature sensor of the microcontroller are the two different ways to accomplish temperature compensation using the BOOSTXL-TLV8544PIR.

    As I mentioned previously, it is recommended to do some testing with the BOOSTXL-TLV8544PIR without modification in order to determine if any changes are needed as a first step.

    Please see answers to your questions below:

    1. that diodes have polarity, cathode have direction to GND, see attached file (Please confirm)

    Yes, correct

    2. can you please suggest part number of diodes (maybe it should have a special requirements: Capacitance, Vf etc.. Or it can be as D4 and D5 (1N4148X-TP) as referring on the schematic on page 22 ?

    1N4148X-TP will work

    3. Sorry, but i not understand the use case of these diodes. I would like learn from professionals FAE like you :), can you please explain use of it to me.

    This is analog temperature compensation of the thresholds for operating in high ambient temperature conditions

    B.

    1. i not understand the used of microelectronic temperature sensor. the gain and level of comperators - U1C and U1D is fix and insert to uC as interrupt. How can play with comparators thresholds and their temperature compensation with digital domain without any hardware modification?

    U1B output already connects to an ADC channel on the CC2650.  You will need to modify the firmware for this option but not hardware.  The interrupts from U1C and U1D outputs would be ignored and digital thresholds in firmware would be set for comparison with the ADC output from the channel sampling the U1B output.  In this scenario, reading the temperature sensor before making the comparison would allow adjustment of the thresholds based on the temperature reading.

    Regards,


    David

  • Hi David

    Sorry for long answer. I will start design the PIR very soon!!!

    Last question, what is a important parameters to choosing a PIR sensor in order to detect mouse/very small animals at distance 5-6m.
    If you can suggest of good sensor i will very appreciate you.

    in the future, how can i contact to you, maybe will be a questions during my development ?
    Again, thank you very much for the time and support.

    Best regyrds

    Ilya

  • Hi Ilya,

    The most important sensor parameter for this application will be the Responsivity.  Larger is better for this parameter.  Secondly, will be the sensor output noise.  Lower is better for this parameter.

    Panasonic and Murata both have extensive portfolios of PIR sensors and both have great technical support to help select the correct device for given applications.

    Aside from the selection of the sensor, it is also very important to select the correct Fresnel lens for the desired range and field of view.  Most often there are lenses designed for use with certain sensors.  The manufacturer will be able to guide the selection based on the application.

    For Murata, a good starting point would be the IRA-E700ST0.  We have used the IML-0669 for wide field of view (>110 degrees) but these lenses are for use with the surface mount sensors and may not work with the IRA-E700ST0.  You will need to contact Murata for the correct wide angle lens for the IRA-E700ST0 sensor and to find out if there is a better sensor available for your application.

    For help during development if you have a local FAE, they will be able to give you support or if needed they will be able to put you in direct contact with me.  Of course you can always reach out through the forum as well.

    Regards,

    David