RoboSavvy Forum

Wheeled Robots • Group of robots in Webots

2015-05-20T22:16:20+01:00

Hi everyone, im newbie in robotics.
I will be very happy if someone gonna help me with Webots.
I want to make group of robots in labyrinth, tried everything, but can't do this simulation.

Statistics: Posted by stylchak — Wed May 20, 2015 10:16 pm

Wheeled Robots • Tank tread platform on kickstarter

2014-11-11T20:33:22+01:00

Wow - the new design of the site and forum look great. I haven't been on in quite some time, I left the ground (Biped, Hexwalker and rovers) for the sky - very addictive. Anyway I worked with the Ardupilot board on my Minds-I 6 wheeled platform but have always wanted a more versatile tank tread and terrain crawling machine.

Just found this guy posted on the DIYDrone site and decided to back the chassis kit - I wanna work on pulling all the electronics together I have the mini APM, PixHawk and Navio (add on for Raspberry Pi) control board to work with and run the APM:Rover

https://www.kickstarter.com/projects/11 ... robotic-pl

My goal is to work on some computer vision combined with sensors, possibly LiDAR for avoidance and SLAM

Statistics: Posted by cdraptor — Tue Nov 11, 2014 8:33 pm

Wheeled Robots • Re: Quadrature hall effect encoders for wild thumpher

2014-04-28T17:12:17+01:00

Hi,

Is it possible to give the cable connections for the encoder to a arduino (digital, PWD or analogic ...) and the meanings of the values of yellow and white pins ?

Statistics: Posted by steph_carre — Mon Apr 28, 2014 5:12 pm

Wheeled Robots • Thumper 6wd

2014-01-11T17:33:59+01:00

Newbie question.

What type of batteries should I buy and what type of charger please.

Does anyone here experience or advice of using the Thumper 6wd with the ArduRover kit?

Ken.

Statistics: Posted by lasatalayas — Sat Jan 11, 2014 5:33 pm

Wheeled Robots • Wild thumper 4wd motors

2014-01-08T13:29:41+01:00

Hi Gang

I am new here and new to robotics, I have just purchased a Dagu 4wd wild thumper and starting to get to grips with it, I have the Arduino controller, I have the unit connected up and working but a couple of things,
1. Two of the motors have what looks like servo wires coming from them White, yellow, red, black where do these connect to?
2. One of the motors is very lumpy when running almost like it has some sort of feedback effecting it, will this be todo with the wires on the above question?

Sorry if I sound stupid but as I say new to this so learning every step of the way,

Thanks in advance, Shaun

Statistics: Posted by Sbisme — Wed Jan 08, 2014 1:29 pm

Wheeled Robots • Re: Quadrature hall effect encoders for wild thumpher

2013-10-14T10:33:04+01:00

Hi flynny75.

Older versions of the motors do not have exposed motor shaft to mount encoders to.

You will have to get the new motors that come with the encoder included:

34:1 version: http://robosavvy.com/store/product_info.php/products_id/1185
75:1 version: http://robosavvy.com/store/product_info.php/products_id/3338

The gearboxes are the same so you will get some spares.

Regards

Statistics: Posted by MarcoP — Mon Oct 14, 2013 10:33 am

Wheeled Robots • Re: Quadrature hall effect encoders for wild thumpher

2013-10-11T13:17:30+01:00

Is this available yet? I cannot find it in the store.

I have an earlier version (about 2 years old, before the encoders were introduced), will I need new motors? Do you also sell those?

Statistics: Posted by flynny75 — Fri Oct 11, 2013 1:17 pm

Wheeled Robots • Timer Interrupts

2013-08-31T05:16:30+01:00

In cases where external interrupt pins are limited the next best way is to create a timer interrupt. This generates an interrupt at precise intervals. The ISR (Interrupt Service Routine) then checks the pins attached to the encoders.

There is an Arduino library here that is quite useful: http://playground.arduino.cc/Code/Timer1

Unfortunately this library uses the same timer as the servo library so you cannot use servos with it unless your using An Arduino Mega or DAGU Spider controller. There is also a timer3 version of the library suitable for these boards.

Alternatively, if your main code repeats quickly enough then simply monitor the inputs with each loop of the program. This is ok for distance measurements but not suitable for speed measurement which needs accurate timing.

I often use the millis() or micros() function to call my ISR once every millisecond. The accuracy of this method depends on how quickly your main loop is running. If your encoders or maximum speed is low enough then you can check your encoder inputs at longer intervals.

Statistics: Posted by OddBot — Sat Aug 31, 2013 5:16 am

Wheeled Robots •

2013-08-30T11:59:31+01:00

I would be very much interested in a solution to what Toby asks - indeed a later revision of the thumpers cam with encoders built into 2 of the motors, so how to connect these up to the thumper controller board would be great to know.

Statistics: Posted by Grumpybeard — Fri Aug 30, 2013 11:59 am

Wheeled Robots •

2013-08-28T13:49:49+01:00

The section is dead totaly. Get over it.

Statistics: Posted by Sensorika — Wed Aug 28, 2013 1:49 pm

Wheeled Robots •

2013-08-26T15:42:05+01:00

What encoders?

I've used QRE1113 reflectance sensors from Sparkfun (Pololu sells these too I think). And it's a matter of giving them power and ground, and then plugging signal into some ports.

On ATmega, you can have an interrupt fired every time there's a transition on these type of reflectance sensors, then write interrupt handler code to increment a counter based on which pin changed. Or if you use ATmega's special INT0 and INT1 pins, you can specific which transition (rising or falling or both) and fire interrupts with handlers unique to each pin.

Statistics: Posted by BotThoughts — Mon Aug 26, 2013 3:42 pm

Wheeled Robots •

2013-08-26T15:39:26+01:00

Digging up old post.

Yes, you need a particular JST cable (Acroname sells them among others who sell the Sharp sensors). They're 5V analog sensors.

Looks like you need your basic 0.1" pin header, crimp female connectors on the other end. You can get the female crimp connectors and housings from Pololu for a decent price in small quantities.

FWIW, I'm building interface boards ("A2D") to convert the Sharp sensors to digital (I2C) with oversampling and filtering to reduce noise and increase resolution. So I have been playing with them a bit Happy to help.

If the boards would help I'll let you have a couple as I'm looking for testers. (Or maybe you're the fellow from Parallax forums who is doing a Wild Thumper project)

Statistics: Posted by BotThoughts — Mon Aug 26, 2013 3:39 pm

Wheeled Robots • Wild Thumper DC Motor Controller Encoder Setup

2013-07-01T23:30:03+01:00

Hey everybody,

anybody could comment my ideas on hooking up Thumper 4WD encoders to the motor controller?

Probably pin D2 and D4 for left encoder and D7 and D8 for right encoder would be ok? Does the color coding white and yellow matter in any way?

Also would you like to share some arduino code for quering encoder state? I would like to learn how you address the fact, that there is only one free interrupt available at D2, so an separate interrupt for left and right encoder is not an option. Thus, do you pack everything in the main loop?

Looking forward for your replies

Cheers
Toby

Statistics: Posted by Toby — Mon Jul 01, 2013 11:30 pm

Wheeled Robots •

2013-05-17T16:07:24+01:00

My USB has just gone and broke off the wild thumper controller board, gutted.

Think quality control was vacant when they built this board.

Statistics: Posted by Grumpybeard — Fri May 17, 2013 4:07 pm

Wheeled Robots • Connect Sharp infrared sensors to Wild Thumper motor control

2013-04-09T14:53:26+01:00

Purchased some sharp infrared sensors that I wish to connect to the Dagu Wild Thumper motor controller for power and data.

I assme these connect to the Analog inputs of the motor controller?

The sharp sensor has a 3 pin JST connector. I imagine I would need a JST cable as a start:

http://robosavvy.com/store/product_info ... cts_id/614

These cables are open-ended at one end. I see the analog inputs are 2 pin, and I dont know what connector type/pitch size they are.

If anyone can recommend what needs to be wired onto the other end of the JST cable it would be most appreciated, even better if there is already a pre-prepared cable at both ends?

Many thanks!

Statistics: Posted by Grumpybeard — Tue Apr 09, 2013 2:53 pm