Parking Sensor
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@korttoma
Even if it's only active for about 3-4minutes per day?
The problem is i got no way of getting power to where i want to place it.
And also if i did it would have to be something like 230V to usb adapter.
And plugging one of those in outside seems like a fire hazzard (even indoors they are known to start fires).What if i hook it up to a small solar panel to charge the batteries?
Otherwise i guess i'll just have to stick with the old tennisball on a string method :D
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@korttoma
Even if it's only active for about 3-4minutes per day?
The problem is i got no way of getting power to where i want to place it.
And also if i did it would have to be something like 230V to usb adapter.
And plugging one of those in outside seems like a fire hazzard (even indoors they are known to start fires).What if i hook it up to a small solar panel to charge the batteries?
Otherwise i guess i'll just have to stick with the old tennisball on a string method :D
@leothlon I'm not saying it can not be done but according to the datasheet the LED chip can consume up to 20mA ( http://www.adafruit.com/datasheets/WS2812.pdf ). So with 24 of them you will be looking at almost 500mA for just the LEDs.
http://ncalculators.com/electrical/battery-life-calculator.htm
btw, there is another thread about safe AC DC transformers here
- Tomas
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@leothlon I'm not saying it can not be done but according to the datasheet the LED chip can consume up to 20mA ( http://www.adafruit.com/datasheets/WS2812.pdf ). So with 24 of them you will be looking at almost 500mA for just the LEDs.
http://ncalculators.com/electrical/battery-life-calculator.htm
btw, there is another thread about safe AC DC transformers here
@korttoma The online documentation I read said:
"The pin labeled PWR +5V is the power input pin, and should be connected to a suitable power supply. An input voltage of 5 V is used to power the ring, and each LED on the ring can draw up to 50 mA at 5 V when outputting white at full brightness. That means the ring could draw up to a maximum of around 1.2 A."
Although Hek's code does not operate all the pixels at full white brightness, I decided to play extra safe and use a 2A supply.
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@korttoma The online documentation I read said:
"The pin labeled PWR +5V is the power input pin, and should be connected to a suitable power supply. An input voltage of 5 V is used to power the ring, and each LED on the ring can draw up to 50 mA at 5 V when outputting white at full brightness. That means the ring could draw up to a maximum of around 1.2 A."
Although Hek's code does not operate all the pixels at full white brightness, I decided to play extra safe and use a 2A supply.
@Dan-S. Yeah I'm sure thats true. Please post a link to the documentation if you can find it. Anyhow I guess we can agree that running this device on batteries would be difficult.
- Tomas
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@Dan-S. Yeah I'm sure thats true. Please post a link to the documentation if you can find it. Anyhow I guess we can agree that running this device on batteries would be difficult.
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@Dan-S. Yeah I'm sure thats true. Please post a link to the documentation if you can find it. Anyhow I guess we can agree that running this device on batteries would be difficult.
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But isn't the distance sensor rather power hungry as well?
The dist-sensor but be awake all the time taking measurements (which needs to be interpreted by the MCU).. so sleep mode is not an option on this.
@hek said:
But isn't the distance sensor rather power hungry as well?
You could wake it with a reed switch attached to the garage door...
door open, sense and display until steady state and go to sleep on a timeout or door closed interrupt
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@hek said:
But isn't the distance sensor rather power hungry as well?
You could wake it with a reed switch attached to the garage door...
door open, sense and display until steady state and go to sleep on a timeout or door closed interrupt
@BulldogLowell said:
You could wake it with a reed switch attached to the garage door...
door open, sense and display until steady state and go to sleep on a timeout or door closed interrupt
I like that idea. I was planning on having garage door sensors tied in with this anyway. FYI here is a link to the ultrasonic module docs which list 15mA as the current draw.
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Just to add my two cents, as I have a window nearby, I'm planning to run my parking sensor with a solar battery bank, like this one.
I'm waiting for the ring now. It is the last piece missing ;-)
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This was fun to build :)
However, my HC-SR04 is making a high pitch sound when distance is close and a more static sound when distance is further. I have tried with 3 different modules and 2 different Nanos and 2 different power sources. Is this normal?
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This was fun to build :)
However, my HC-SR04 is making a high pitch sound when distance is close and a more static sound when distance is further. I have tried with 3 different modules and 2 different Nanos and 2 different power sources. Is this normal?
@msebbe It's normal for a :dog: or a bat. :laughing: Either you have really good hearing, or there's something wrong with your HC-SR04. The ultrasound is supposed to be well above human hearing range (40 KHz). My HC-SR04 is quiet and I don't hear any sound from it.
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This was fun to build :)
However, my HC-SR04 is making a high pitch sound when distance is close and a more static sound when distance is further. I have tried with 3 different modules and 2 different Nanos and 2 different power sources. Is this normal?
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This was fun to build :)
However, my HC-SR04 is making a high pitch sound when distance is close and a more static sound when distance is further. I have tried with 3 different modules and 2 different Nanos and 2 different power sources. Is this normal?
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@msebbe It's normal for a :dog: or a bat. :laughing: Either you have really good hearing, or there's something wrong with your HC-SR04. The ultrasound is supposed to be well above human hearing range (40 KHz). My HC-SR04 is quiet and I don't hear any sound from it.
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Was checking out operation of parking sensor after changing MAX_Distance to 200 from original 100--wanted earlier start from wall. Also changed the Panic distance to 60--more space from wall during testing. Noticed that the led ring did not start from 1 pixel and increase from there as the distance closed. It started at 7 lit pixels. Examined the formula for newLightPixels and made a change which corrected this.
The current newLightPixels formula is:
int newLightPixels = NUMPIXELS - (NUMPIXELS*(displayDist-PANIC_DISTANCE)/MAX_DISTANCE);
The portion of the newLightPixels formula (displayDist-PANIC_DISTANCE)/MAX_DISTANCE) is intended to map the interval between PANIC_DISTANCE and MAX_DISTANCE to the interval (0,1). In other words, when you are at the PANIC_DISTANCE it should calculate to 0 and when you are at MAX_DISTANCE it should calculate to 1, advancing linearly between the two values as the distance closes and vice versa. Clearly when a displayDist = PANIC_DISTANCE, the numerator of the division of the formula calculates to 0. However when displayDist = MAX_DISTANCE, it does not calculate to 1.
In order to correct this I changed the portion of the formula to:
(displayDist-PANIC_DISTANCE)/(MAX_DISTANCE-PANIC_DISTANCE))
Note the only difference is subtracting the PANIC_DISTANCE from the MAX_DISTANCE in the denominator. Now when the displayDist = MAX_DISTANCE, the formula returns the value 1. So the proposed new newLightPixels formula is:int newLightPixels = NUMPIXELS - (NUMPIXELS*(displayDist-PANIC_DISTANCE)/(MAX_DISTANCE-PANIC_DISTANCE));
I tested it both by plugging values into the formula and in operation of the Parking Sensor. Now the leds climb smoothly from 0 as you enter the MAX_DISTANCE zone. rather than starting at some number other than 1 (7 in my case).
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Cool, I had this happen as well, so great fix! Now all I need it to do is talk to domoticz, not picking it up yet... :)
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Have one more proposed change to parking sensor code. Noticed that even when I was standing still there seemed to be quite a few changes in number of leds lit. In checking the internet, learned that variability of distance readings was particularly a problem for those using the sensor in robots. The preferred solution seemed to be taking the median of several readings.
See:
http://blog.microcentertech.com/2013/05/minipingbot-construction.htmlFortunately, the Newping library has a built in function to address this issue by taking the median of several readings (default = 5). So I modified the code as follows:
// int fullDist = sonar.ping_cm(); original code
unsigned int fullDist = (sonar.ping_median() / US_ROUNDTRIP_CM);
// Get average distance for 5 pings, convert to cm
// US_ROUNDTRIP_CM = distance sound travels in cm/secAs a result, the jumping around of the number of leds appears to have decreased significantly and the response is much more stable. Hope this helps others.
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Have one more proposed change to parking sensor code. Noticed that even when I was standing still there seemed to be quite a few changes in number of leds lit. In checking the internet, learned that variability of distance readings was particularly a problem for those using the sensor in robots. The preferred solution seemed to be taking the median of several readings.
See:
http://blog.microcentertech.com/2013/05/minipingbot-construction.htmlFortunately, the Newping library has a built in function to address this issue by taking the median of several readings (default = 5). So I modified the code as follows:
// int fullDist = sonar.ping_cm(); original code
unsigned int fullDist = (sonar.ping_median() / US_ROUNDTRIP_CM);
// Get average distance for 5 pings, convert to cm
// US_ROUNDTRIP_CM = distance sound travels in cm/secAs a result, the jumping around of the number of leds appears to have decreased significantly and the response is much more stable. Hope this helps others.
@Dan-S. Thanks for your investigation! I made the changes and it seems to work well!
About the high pitch sound I mentioned earlier; I changed NEO_KHZ400.
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, NEO_PIN, NEO_GRB + NEO_KHZ400);to
NEO_KHZ800This removed the annoying high pitch sound :D
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@Dan-S. Thanks for your investigation! I made the changes and it seems to work well!
About the high pitch sound I mentioned earlier; I changed NEO_KHZ400.
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, NEO_PIN, NEO_GRB + NEO_KHZ400);to
NEO_KHZ800This removed the annoying high pitch sound :D
@msebbe Glad everything worked out well for you. Your comment made me think about changing mine to 800 also. From what I could glean from looking on the internet, 800 is more appropriate for newer devices, e.g., the led ring. So I am going to change to 800 also. Thanks.
