Ebay Laser & Sensor Tests FYI
Just received lasers & two different sensors. Quick test results, FYI.
PCB lasers: 5pc/$2.75
3 pin connector:
-=ground
center=NC
S=+5V
![s-l500.jpg](http://i.ebayimg.com/images/g/vl4AAOSwCGVYBubI/s-l500.jpg)
$15 sensor, emits DC laser beam
Lens over phototransistor (you apply using mini foam tape pads)
3xAA cells
digital output, active low, very color dependent
1 red power LED
1 red sense LED
white surface max range ~36"
black plastic computer case/battery box ~12-18"
black resin watch strap ~12"
dark brown fabric ~8"
black fabric not detected
![s-l500.jpg](http://i.ebayimg.com/images/g/9moAAOSwcu5UP5b4/s-l500.jpg)
$1 analog sensor
1 red power LED
dark = 0V
output varies up to 4.12V when illuminated by red laser
get ~1V fluctuating from IR remote close/pointblank
![s-l500.jpg](http://i.ebayimg.com/images/g/4asAAOSwRgJXmI0L/s-l500.jpg)
BTW I received ten of these $3.72 Sharp IR sensors and the one I tested worked fine.
http://www.ebay.com/itm/262134861038
PCB lasers: 5pc/$2.75
3 pin connector:
-=ground
center=NC
S=+5V
![s-l500.jpg](http://i.ebayimg.com/images/g/vl4AAOSwCGVYBubI/s-l500.jpg)
$15 sensor, emits DC laser beam
Lens over phototransistor (you apply using mini foam tape pads)
3xAA cells
digital output, active low, very color dependent
1 red power LED
1 red sense LED
white surface max range ~36"
black plastic computer case/battery box ~12-18"
black resin watch strap ~12"
dark brown fabric ~8"
black fabric not detected
![s-l500.jpg](http://i.ebayimg.com/images/g/9moAAOSwcu5UP5b4/s-l500.jpg)
$1 analog sensor
1 red power LED
dark = 0V
output varies up to 4.12V when illuminated by red laser
get ~1V fluctuating from IR remote close/pointblank
![s-l500.jpg](http://i.ebayimg.com/images/g/4asAAOSwRgJXmI0L/s-l500.jpg)
BTW I received ten of these $3.72 Sharp IR sensors and the one I tested worked fine.
http://www.ebay.com/itm/262134861038
Comments
Either way, one or more visible laser dots on the line are a win win.
Find me one person who doesn't like blinking LEDs and laser beams. I dare you. Even cats like lasers!
The schematic at http://www.waveshare.com/w/upload/9/98/Laser-Sensor-Schematic.pdf makes it look like the clear "phototransistor" adjacent to the brass laser tube is actually doing the modulating. Sorta makes sense.
There just ain't that much other circuitry on the board, there's a PT1301 5V booster (module can be powered from 2.5-5V) with coil, SS14 Schottky diode & passives. Also two J3Y transistors and two SMT LEDs & resistors.
Without the lens, that ~36" max working range goes down to ~8".
I tested it outdoors last night with some mediocre retroreflector material (as I used with the S6986) and it worked at an astounding 60-70 FEET! It may work nearly as well in the daylight with proper shielding from sunlight.
How did we live this long without this sensor? If you call that livin'...
Just get one and use standard laser good sense & eye protection. This may be the last erco-approved buy of 2016! Turns out they are available from many sources:
http://www.ebay.com/itm/251680140316
http://www.robotshop.com/en/obstacle-detection-laser-sensor.html
http://www.waveshare.com/Laser-Sensor.htm
https://www.aliexpress.com/item/Waveshare-Laser-Receiver-Module-Laser-Sensor-Module-Transmitter-Module-for-STM32-AVR-PIC/2042529584.html
https://www.amazon.com/Waveshare-Laser-Receiver-Sensor-Transmitter/dp/B00NJNYQ9G
A laser-guided BoeBot must be built over Christmas break!
As per erco's tests, it has an impressive sensing range, and would make a good black line follower.
It is not much good for object detection because it black and soft objects do not reflect the laser beam very well.
I covered the module's laser with double sided tape and did some experiments with an external red laser;
- The lower bound of modulation for detection is about 18kHz. There is no upper bound. The datasheet claims a modulated beam of 180kHz (maybe they mean 18kHz? ? ?)
- If the external laser is pulsed or modulated the digital output at the detection data pin is nice and clean and the module can probably be used as a remote controller or for data transmission. At a modulation of 50kHz, it transmitted a 1200Hz pulse stream quite cleanly. I did not try any actual data transmission.
Keep up your fine work!
Hello,dear
your question: ". The laser modulation is actually 180 kHz? And what does the extra phototransistor near the brass laser do?"
our engineer said: That is the Modulated Tubes, which is modulated the laser as a regulated rate and send ,there is a receiving tube under the lens, which is used for receiving the fixed rate
Best I can tell, that phototransistor-looking component on the PCB by the brass laser tube is in series with the laser diode and modulates the output for detection by a similar companion receiver. Q1 on the attached schematic. The send/receive circuitry is quite minimal. Most of the components on the sensor board are for a PT1301-based 5V booster to run the sensor from as little as 2.5V. Propeller and 3.3V users, rejoice!
Schematics and "user manual" attached. From http://www.waveshare.com/wiki/Laser_Sensor
So why hasn't anyone except macrobeak bought these yet? It's Christmas! Stuff your stocking!
AFAIK Robotshop is still cheapest at $9.99 (plus shipping, ugh!)
And what is shockwave? My favorite Shockwave is:
Got to see and touch at two Nashville Airshows.
Friendly aren't they, of course you may be a frequent customer.
Ordered one from Amazon. $15.99 free ship.
No, Jim, you'll shoot your eye out! Ho, ho ho!
http://www.servomagazine.com/index.php/magazine/article/April2017_MrRoboto
I love that BS2 laser scanner.
XLNT. Plenty of Stamp love in that article. The DVD-chassis robot shown in figure 3 is BS-2E powered.
WRT Lidar, that laser sensor can't measure range. Just whether it sees a reflection or not, which is very dependent on the object and color. Parallax's PING-dar project remains a favorite of mine. A worthy improvement would be to combine a PING ultrasonic rangefinder with a Sharp IR rangefinder in a similar scanning arrangement to combine sensor strengths.
Wonder if the price is right, cheap.
Pages are to big for me to browse.
http://leddartech.com
Thanks for the link;
http://leddartech.com
Very impressive lidar modules of various complexities.
All sub $1000, some sub $500.
All have 5V power supply and 3.3v UART, so Prop interfacing should be straightforward.
I look forward to seeing some really interesting applications from these modules.
https://www.sparkfun.com/products/14032
https://buy.garmin.com/en-US/US/p/557294
Yeah, I actually hoarded this a month ago when I was in US to save some shipping and customs fees. Have hooked it up and secured it's working alright, now it's just waiting for a suitable project...
https://en.wikipedia.org/wiki/Leddar
Last year I saw a demo of LEDar by Leddartech. http://leddartech.com/modules/m16-multi-element-sensor-module/ A tiny dev kit that could detect objects out to some meters and provide 16 channels across the width of view. No moving parts.
I thought, Hmm.. can't we do that with a Propeller? ...
I'm downloading the datasheet now.
Till you mentioned LEDs, I didn't know how it was done. I bet it's doable.