SparkFun Electronics Commentsurn:uuid:214d0e4e-f1b1-d287-ce26-ac5b4c9f82492024-03-28T15:15:06-06:00SparkFun ElectronicsTheRoboMaker on ROB-12629 - Wheel Encoder KitTheRoboMakerurn:uuid:d9775aec-4534-8164-47dd-60df801040442015-06-13T14:54:30-06:00<p>How do I work this?! Example code, anyone?</p>
EddieDude on ROB-12629 - Wheel Encoder KitEddieDudeurn:uuid:6d7acaeb-d88a-88b9-6065-4ace4c3533342015-05-13T11:28:45-06:00<p>I have the DGo1D 48:1 motors, but the shaft only sticks out about 1 mm. But according to the Redbot kit, the motors for the same part have a shaft extending about 1 cm (just a guess from the picture). My motors also have a black cap instead of a red one. So I assume my motors are old, so I tried to find new motors and they look totally different (they are right angled). Will these work with RedBot?
https://www.sparkfun.com/products/13260</p>
HAWP on ROB-12629 - Wheel Encoder KitHAWPurn:uuid:9c4de619-097b-7dcf-7168-784bde3457852014-10-26T12:14:17-06:00<p>Do you need to use both if you want to tell which direction it's going?<p>-edit: found the answer. it seems like it should be possible to use two sensors to get the quadrature benefit, but it seems like it's going to be too difficult for me to get them precisely mounted well enough for it to work correctly. I'm also not sure how well that would work with Hall sensors since they detect a spectrum (analog) signal as opposed to the 1/0 of an optical encoder. I'm just going to get the quadrature encoder (COM-10932) to keep myself sane.</p></p>
kpdangelo on ROB-12629 - Wheel Encoder Kitkpdangelourn:uuid:0cb2ca60-cc33-aefd-906c-6827407e75f22014-09-10T12:01:03-06:00<p>Great inexpensive encoder. If you want to use it for a Boe-Bot, here's the longer replacement screw you need for the wheel hub (took me forever to find)
http://www.amazon.com/gp/product/B00GDY5C00/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
it's a #3-24 panhead 1/2" long</p>
Troy Lavigne on ROB-12629 - Wheel Encoder KitTroy Lavigneurn:uuid:a3604a07-73fe-084e-c478-716b62bd55342014-05-16T10:42:14-06:00<p>When connecting to the RedBot will this connect to the motor shaft (rear of RedBot) or to the gearbox output shaft? Hopefully it's the motor shaft.<p>Is the RedBot encoder count 48x8=384 ticks / wheel revolution? If so, pretty good upgrade from the current 16 count/rev motor encoder.</p></p>
brennen on ROB-12629 - Wheel Encoder Kitbrennenurn:uuid:c33960c7-1893-e69a-fb73-5524de35a4492014-05-16T10:34:35-06:00<p>The asterisk never lies.<p>Well, unless I tell it to lie. In that case it might.</p></p>
FractalBrain on ROB-12629 - Wheel Encoder KitFractalBrainurn:uuid:d63e9e80-fb31-3875-fc3d-5b55603784862014-05-15T15:41:33-06:00<p>Their are just mounds for the censors?</p>
RobertC. on ROB-12629 - Wheel Encoder KitRobertC.urn:uuid:0eeb8f72-50ae-63c1-1f6e-3981308c68452014-05-15T15:32:45-06:00<p>mounds? I clearly said mounts.</p>
brennen on ROB-12629 - Wheel Encoder Kitbrennenurn:uuid:70eca4f3-60bb-1c53-94f6-a020871953e22014-05-15T15:31:57-06:00<p>Mounds of <em>what</em>, Rob?</p>
RobertC. on ROB-12629 - Wheel Encoder KitRobertC.urn:uuid:849eee31-e9c4-7408-e6ab-e10dad0db94e2014-05-15T14:13:51-06:00<p>They are just mounts for the sensors.</p>
Customer #507175 on ROB-12629 - Wheel Encoder KitCustomer #507175urn:uuid:75ed0cd0-ec8d-4a93-b9c0-cff5edde63542014-01-25T02:46:56-07:00<p>Could these be used with servo motors, with the magnetic disc screwed on between the wheels and the servo axle (perhaps with longer screws)?</p>
Customer #468460 on ROB-12629 - Wheel Encoder KitCustomer #468460urn:uuid:5cd79c53-55ff-2a9e-3d3a-b280839725e72013-12-28T14:54:16-07:00<p>I have reason to believe the hall effect sensors are <a href="https://www.sparkfun.com/products/9312" rel="nofollow">these.</a> The yellow strips are probably adhesives.</p>
Customer #294085 on ROB-12629 - Wheel Encoder KitCustomer #294085urn:uuid:703d9e7c-5220-17b9-f9d9-3452a6de296b2013-12-11T11:28:50-07:00<p>My guess is that he doesn't talk about the torque of the motor since it is a motor spec, but the torque that is transferred to the ground (i.e. the wheels grip the ground better because of skid detection?). Just a thought.</p>
Customer #279477 on ROB-12629 - Wheel Encoder KitCustomer #279477urn:uuid:64494a54-24cb-a531-065e-8af5f803ef902013-12-11T08:09:39-07:00<p>Accuracy can be thought of as how repeatable is each pulse. Consider the mythical monopole magnet and detect only the rising edge. If you label that as 0 degrees, will it always be 0 degrees, or will the reading wander from 359 to 1 degree? Will it wander from 350 to 10 degrees? How will RPM affect accuracy? I think it would be fun to build a car distributer that will use a knock sensor to advance timing for max engine efficiency under all conditions for a vintage engine. Part of that project would be to know where the crankshaft rotation is to less than a degree. I don't have to measure each degree, I can interpolate if the readings have accurate repeatability.</p>
jwatte on ROB-12629 - Wheel Encoder Kitjwatteurn:uuid:da9b5e1e-3add-1d68-3501-28045d2bb2da2013-12-09T09:37:27-07:00<p>I don't think so. I think the rise/fall is already included in the "poles." 8 poles means 4 magnets. 4 magnets timesd two poles/states each (north and south, high-and-low) times two encoders equals 16 transitions/counts. I could be mis-understanding how the poles are counted, though.</p>
Citros on ROB-12629 - Wheel Encoder KitCitrosurn:uuid:0f482a73-956d-79c9-81ac-a66afb77355a2013-12-08T21:01:02-07:00<p>How would this give you Torque?</p>
Ted M on ROB-12629 - Wheel Encoder KitTed Murn:uuid:4a390f80-5a61-ec75-16ca-5c1fede02a312013-12-07T09:31:15-07:00<p>What are the yellow strips shown in the picture?
Do you have a part number or datasheet on the actual sensors?</p>
sramkod on ROB-12629 - Wheel Encoder Kitsramkodurn:uuid:327a79bf-dec8-d586-595c-1d939c83b93d2013-12-07T06:46:37-07:00<p>You can get 32 counts per revolution with this configuration if you can detect rising and falling edges on both channels. Though I don't know if these edges would be equally spaced with this magnetic encoder.</p>
Bajdi on ROB-12629 - Wheel Encoder KitBajdiurn:uuid:ec05663b-7a68-f036-364e-b64978080e4b2013-12-06T14:42:24-07:00<p>These work very well with the cheap yellow motors. With some simple code my motors now have lots more torque. http://www.bajdi.com/adding-encoders-to-those-cheap-yellow-motors/</p>
jwatte on ROB-12629 - Wheel Encoder Kitjwatteurn:uuid:dc77d11c-e678-02f3-5309-0de0a6eec4d32013-12-06T12:06:41-07:00<p>8 poles and 2 encoders should give you 16 counts per revolution. 360/16 is 22.5 degrees per count. With 100 mm wheels (4") that would give you about 2 cm per count.
I'd like to know what the output is -- is it totally raw Hall sensors that need conditioning, or is there any clean-up of the signal to turn it into something nice?
(Answered my own question: The outputs are open-drain, so all the clean-up needed is a pull-up resistor.)</p>
JohnK-EvilMinion on ROB-12629 - Wheel Encoder KitJohnK-EvilMinionurn:uuid:ef4172d0-99b9-15c1-f285-2e83cef9d2cb2013-12-06T10:08:31-07:00<p>What is the i/d of the magnet with the rubber hub removed? The motor drive on my robot uses 3/8" shafts. What is the o/d?
I also suspect the magnet will pick up all sorts of cr_p from the ground if mounted to close to the ground. Fortunately my motor mounts are 6+" above the base.</p>
JohnK-EvilMinion on ROB-12629 - Wheel Encoder KitJohnK-EvilMinionurn:uuid:c053499e-a9a5-5f56-d2e8-790a8356f96c2013-12-06T10:04:43-07:00<p>I suspect 1/8 of a revolution based on the 8 poles of the magnet.
Edit -- I forgot there were 2 sensors. jwatte is correct!</p>
Customer #430559 on ROB-12629 - Wheel Encoder KitCustomer #430559urn:uuid:3aea2698-7a00-0471-5879-2c0d1c0c350c2013-12-06T09:45:14-07:00<p>How accurate are these? How small an increment of rotation can be detected?</p>