Page 3 of 8 FirstFirst 1234567 ... LastLast
Results 21 to 30 of 77

Thread: LIDAR-lite 360 Mirror Scanner

  1. Re: LIDAR-lite 360 Mirror Scanner

    OMG, that's superb! It's incredible to see it in action!

  2. #22
    Join Date
    Mar 2015
    Location
    Texas
    Posts
    342
    Images
    15
    Rep Power
    27

    Re: LIDAR-lite 360 Mirror Scanner

    Quote Originally Posted by jwatte View Post
    A belt has less backlash but more risk of slip. Seems easier to get to run smoothly and quietly, though.
    Ah yes. A belt would be nice because it is a little noisy. I was able to reduce the noise a great deal by adjusting the current potentiometer. Changing the rotation speed actually helps keep the resonation down a bit. I created the gears myself so I'm assuming a good gear generator will also help the situation.

    Quote Originally Posted by tigakub View Post
    OMG, that's superb! It's incredible to see it in action!
    Hah! Thank you! I've gotten the scan rate down to 2-3 seconds per rotation while still being able to see things like my head and arms in the air in one pass. Moving away from the Teensy helped a lot because I couldn't get the readings faster than 40ms over I2C in the time I'm willing to spend on this. Sorry pink teensy.. till another time.

    So I switched to a Mega clone that has no trouble reading at 15ms (currently). I hacked up a SparkFun audio shield that they sent me a bunch of in some of those grab bag boxes. Turns out it did come in handy for something =) Now I removed the breadboard and added a socket to plug in a motor driver. Everything is a little more secure for prototyping now and that makes me happy

    Click image for larger version. 

Name:	IMG_1744.jpg 
Views:	172 
Size:	144.3 KB 
ID:	6057

    Now since I'm really starting to like the results I plan to improve the base of the design. Here I'm thinking support the entire bearing (two posts are missing) and I'll likely make the posts separate printable parts to speed up the printing time. Also gives you the ability to use other standoffs to vary the height of the mirror depending on the height of the motor used. I'd also like to be able to fasten the motor because currently it sits a couple mm in a perfectly sized cutout and increase the overall strength of the base since the first pass I try to waste as little time and plastic as possible.

    Finding a good gear generator will also be on the todo list as well as making a more secure mirror holding bracket. I'm open to suggestions and if there is anything anyone would like to see tested let me know please.
    01001001001000000100110001101111011101100110010100 10000001010010011011110110001001101111011101000111 0011

    My Instagram
    My YouTube

  3. #23
    Join Date
    Sep 2010
    Location
    ಠ_ಠ
    Posts
    2,181
    Images
    27
    Rep Power
    267

    Re: LIDAR-lite 360 Mirror Scanner

    Quote Originally Posted by jwatte View Post
    A belt has less backlash but more risk of slip. Seems easier to get to run smoothly and quietly, though.
    A properly sized and tensioned timing belt should never slip, and mcmaster sells MXL and XL belts in many sizes for a few dollars each. Their pulleys can be a bit more expensive at $7~15, but I expect there are programs out there to generate the correct trapezoidal profile given the popularity of timing belts in 3D printers.

    There was a rather nice looking gear generator linked in this thread not too long ago. edit: the most common pressure angle used to be 14.5 degrees, but has been a general shift to 20 degrees for heavier load handling. Since they are custom printed and unlikely to interact with 'standard' gears and there is not much of a load it should not really matter much what parameters are used.
    Last edited by tician; 06-22-2015 at 01:17 PM.
    Please pardon the pedantry... and the profanity... and the convoluted speech pattern...
    "You have failed me, Brain!"
    bleh

  4. #24

    Re: LIDAR-lite 360 Mirror Scanner

    Again Great Work!

    Still wondering what is going on with the Teensy... I know you should be able to do very high speed I2C communications with it, so wondering about what is causing this... Maybe I should hook mine up

    Kurt

  5. #25
    Join Date
    Mar 2015
    Location
    Texas
    Posts
    342
    Images
    15
    Rep Power
    27

    Re: LIDAR-lite 360 Mirror Scanner

    Quote Originally Posted by tician View Post
    A properly sized and tensioned timing belt should never slip, and mcmaster sells MXL and XL belts in many sizes for a few dollars each. Their pulleys can be a bit more expensive at $7~15, but I expect there are programs out there to generate the correct trapezoidal profile given the popularity of timing belts in 3D printers.

    There was a rather nice looking gear generator linked in this thread not too long ago. edit: the most common pressure angle used to be 14.5 degrees, but has been a general shift to 20 degrees for heavier load handling. Since they are custom printed and unlikely to interact with 'standard' gears and there is not much of a load it should not really matter much what parameters are used.
    I do believe they were set at a 2:1 ratio with about a 25 degree angle. I made the pinion gear a size that looked decent for the number of teeth but I don't recall the diameter. That was the gear generator I remember seeing and I tried to use that at first but was given too much grief when attempting to bring the generated files into the model. Actually my first attempt at printing the gears I made them look like what was generated on that website and it would turn fine by hand the motor wasn't strong enough. Then I doubled the number of teeth and changed the angle and I have what was shown.

    I think a belt is going to be the way to go. It should be smoother and nearly silent. Thanks for the link.

    Quote Originally Posted by KurtEck View Post
    Again Great Work!

    Still wondering what is going on with the Teensy... I know you should be able to do very high speed I2C communications with it, so wondering about what is causing this... Maybe I should hook mine up

    Kurt
    Thanks. Me too. The Teensy should be perfectly capable. I skimmed though all those pages a couple times and tried their examples. There was only one that seemed to read continuously but if you added the delay of formatting and sending an output string it would eventually hang. I probably sat down with it 3 or 4 times trying to adjust what I thought should work and felt silly when I'd see mega doing nothing so I made the switch.
    01001001001000000100110001101111011101100110010100 10000001010010011011110110001001101111011101000111 0011

    My Instagram
    My YouTube

  6. #26
    Join Date
    Sep 2010
    Location
    ಠ_ಠ
    Posts
    2,181
    Images
    27
    Rep Power
    267

    Re: LIDAR-lite 360 Mirror Scanner

    A word of warning about McMaster-Carr: their warehouses are essentially UPS shipping/distribution centers. This means most things are shipped same day as ordered but also means UPS ground is the cheapest option they offer, so small and inexpensive (<$20) orders are not recommended. Fortunately, there are all sorts of goodies in their catalog (I've lost many hours wandering through it), so finding things to pad out the order to make it worth the shipping cost is usually pretty easy.
    Please pardon the pedantry... and the profanity... and the convoluted speech pattern...
    "You have failed me, Brain!"
    bleh

  7. #27
    Join Date
    Mar 2015
    Location
    Texas
    Posts
    342
    Images
    15
    Rep Power
    27

    Re: LIDAR-lite 360 Mirror Scanner

    Haha.. Warning. Lot's of shopping. Don't spend all the money.
    01001001001000000100110001101111011101100110010100 10000001010010011011110110001001101111011101000111 0011

    My Instagram
    My YouTube

  8. #28

    Re: LIDAR-lite 360 Mirror Scanner

    Quote Originally Posted by r3n33 View Post
    Thanks. Me too. The Teensy should be perfectly capable. I skimmed though all those pages a couple times and tried their examples. There was only one that seemed to read continuously but if you added the delay of formatting and sending an output string it would eventually hang. I probably sat down with it 3 or 4 times trying to adjust what I thought should work and felt silly when I'd see mega doing nothing so I made the switch.
    I looked at those pages as well and was hoping that Paul would have a solution for it... Again sounds like a fun thing to look at...

    Watch it turn it that the Lidar simply does not like 3.3v signals... Maybe I will grab one of my Seeedstudio megas with one of my breakout boards and see what the signals look like...

    Kurt

    Edit: I currently have Paul't test program in posting 89 (https://forum.pjrc.com/threads/28036...ll=1#post70214) and I am running it on a purple Teensy 3.1 using Arduino 1.6.5r2 with Teensyduino 1.24 beta 3 which appears to have Pauls updated Wire.cpp file (used winmerge to compare the file he had in posting to one installed by Teensyduino). So far maybe 30 minutes in no hangs average time probably 10 millis...
    Last edited by KurtEck; 06-22-2015 at 08:10 PM.

  9. #29

    Re: LIDAR-lite 360 Mirror Scanner

    finding things to pad out the order to make it worth the shipping cost is usually pretty easy
    I used to think like that, but then I realized that an order for a $3 box of screws and $7 shipping actually costs me less dollars than an order for a $3 box of screws, $7 shipping, and $28 of other miscellaneous stuff that I might not ever get around to actually using...

    That being said, if Small Parts has that same box for $4, free Prime shipping makes that the better choice. Small Parts are hit-or-miss on what's in stock, though.

  10. #30
    Join Date
    Mar 2015
    Location
    Texas
    Posts
    342
    Images
    15
    Rep Power
    27

    Re: LIDAR-lite 360 Mirror Scanner

    So for good practice I decided to take a crack at bringing this home made scanner into ROS. At first I thought I could emulate the Neato XV-11 protocol but when I got knee deep in code I realized it wasn't going to work out as well as I had hoped. So instead a pretty crude ROS node was born that handles the data the way I'd like to output from my scanner.

    Here is the first signs of life from the Lidar scanner in ROS! Weeeee! Can't wait to see what else it can do.

    Click image for larger version. 

Name:	Screenshot from 2015-06-23 22:45:49.jpg 
Views:	825 
Size:	66.6 KB 
ID:	6060
    Last edited by r3n33; 06-24-2015 at 03:24 PM.
    01001001001000000100110001101111011101100110010100 10000001010010011011110110001001101111011101000111 0011

    My Instagram
    My YouTube

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Converting my PhantomX Hexapod to ODroid XU3-lite and ROS...
    By KurtEck in forum Humanoids, Walkers & Crawlers
    Replies: 79
    Last Post: 10-01-2015, 07:56 PM
  2. Question(s) Serial Transmission being interrupted by Serial Receiver [Arbotix + Dynamixel AX-12 + LIDAR Lite]
    By rishflab in forum Arbotix, Microcontrollers, Arduino
    Replies: 4
    Last Post: 04-14-2015, 06:05 PM
  3. Pro Lite V2 vs. Turnigy LiPo's
    By Stobs in forum Power
    Replies: 7
    Last Post: 11-10-2011, 10:14 AM
  4. News/Announcement The Open Lidar Project - Hack the Neato XV-11 Lidar for a $200 Bounty!
    By gallamine in forum Robotics General Discussion
    Replies: 196
    Last Post: 08-19-2011, 12:09 AM
  5. Recommended 24V Battery for laser scanner?
    By wmccafferty in forum Power
    Replies: 4
    Last Post: 09-13-2010, 03:38 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •