The Robotis TurtleBot3

[KurtEck]

I am glad you have it all working!

With the cliff detection stuff, I have code setup currently in simple test app, that currently can read three of the VL6180 sensors from Adafruit. They are I2C devices that by default all have the same address... So I also have one of the Adafruit I2C Multiplexer, I currently have them all in a breadboard and it appears like the test app is working.

Next up is/was to mount the devices (I actually have 4 of them). One above and slightly in front of each of the Wheels, probably one toward center of front and maybe one toward center of back.

But I know that Robotis is planning on doing something similar, As mentioned on RobotSource , which the Robotis Pyo mentioned they will be adding sensors this month. They mention using IR sensor using Analog inputs... So I ordered 4 of the Robotis distance sensors, but they have range of 10-80cm, so might have to mount them with extenders from Top deck.
Or maybe get some other IR sensors. Again most of the Sharp sensors are in the 10+cm range. Some or shorter distances, but are 4.5-5.5v range. Luckily the OPenCR IO pins are 5v Tolerant but in analog mode everything about 3.3v registers as full value.

The benefit of using their sensors, is that they come with their standard 5 pin connectors and maybe some easy method to mount...

So currently deciding how best to integrate...

Also wondering about mounting the OpenCR on the upper deck of the waffle, as to make it easier to hit the B2 + reset when I need to reprogram and it won't go into program mode. Also maybe mount an LCD on it. Probably would imply that I need to update several configuration things to make ROS happy (position of the IMU vs center...

I am sort of going in slow motion on this as so many other things to do outside!

[LloydF]

Wow! Sweet thank you for sharing.

[KurtEck]

So I now have three other options that I ordered that shipped today.

I have 4 of the Robotis Distance sensors: Distance Measuring Sensor DMS-80
Distance Measuring Sensor DMS-80

I have 4 of the Robotis IR sensors: IR Sensor IRSS-10


I have 4 of the #2450 Sharp GP2Y0A51SK0F Analog Distance Sensor 2-15cm from Pololu, They want input voltage 4.5-5.5V so will see how well they work at 3.3v...

So hopefully within the week I will have a few options

[KurtEck]

I thought i would mention, that Robotis released a new update for the Turtlebot3 code base. They announced it in:
https://discourse.ros.org/t/announci...-0-update/4888

Here is some of the information:

Thank you to all who loved TurtleBot3 for the past year
We celebrated the first anniversary of TurtleBot3 and prepared software and firmware updates and more powerful WiKi
This update considered may issues and requests from users. We are sincerely thankful to them.
TurtleBot3 can get even better through a lot of interest. So please feel free to suggest any functions or ask questions into our issue page in github
New Software version is 1.0.0
New Firmware version is 1.2.0
1. List of Software updates
(1) turtlebot3
• Add cartographer
• Add frontier_exploration
• Add frontier_exploration
• Add hector mapping
• Add karto SLAM
• Update gmapping parameters
• Update navigation parameters
• Modified version check
• Add robot model for OpenManipulator and turtlebot3_autorace
(2) turtlebot3_simulations
• Add world for turtlebot3_autorace
• Add world for turtlebot3_machine_learning
(3) turtlebot3_applications
• Add turtlebot3_automatic_parking
• Add turtlebot3_automatic_parking_vision
2. List of Firmware updates
• Add example to use additional sensors as Bumper, Infrared sensor, Ultrasonic sensor, illumination sensor and additional GPIO as LED
• Add debug code for firmware developer

I have been playing around with some of it with their develop branch... Looks like time to sync up everything!

[LloydF]

Yea! Thank you for the heads up.
I order a few sensors to play with, now that i am all updated, seems you had a lot to do with making this happen, thank you.

[KurtEck]

I am trying to help out, as a way to learn things.

I hope my pestering them, is helping to improve things as well.

Over the last few days, I have been playing around with some some different sensors, including a few from them as well as a small range IR sensor by Sharp (picked up from Pololu), I think for now I will settle on using their IR sensor as I think it will work. I need to print up some simple brackets to hold them on. The sensors already have the 6mm brackets setup to use with their rivets. So I think I can mount them with rivets probably to the 2nd deck that extends it out, probably to over each wheel and maybe one on front and Rear.

I am looking over how best to integrate them. The new release added some sensors, but so far they are simply as example and not really on how to use them. Like one Cliff, two bumpers, one sonar which all may simply return real values for cliff and sonar and uint8_t for bumpers

So I will try to ask them, how they would prefer this to be extended/customized.

Currently a bunch of things are hard coded, like the Cliff sensor uses the OLLO objects on ollo connection 2 (hard coded #). I would like to make these defined in the configuration info.

Then for cliff, would like to then setup to use some Ros parameters to maybe define some cliff states... Lots to play with!

[LloydF]

Odd, while building a new TB3 I could not get the motors ID#one and two to work.
I only had to program them on the U2D2 and set the ID's before.
This time I had to use the Arduino Example code turetlebot3_setup_motor to set the right and left Dynamixel's up. This seems to be
requiring you install the Arduino IDE now. It is all good, just a heads up.

[KurtEck]

Thanks for the heads up.

I have not had not tried to have the wheels turn for a bit as I am still playing with the firmware for the openCR board.
I have another SPI port working on the external connector (pins 57-60).

Right now trying to cleanup/enhance their SPI code. Might later do as well with another I2C device Probably on pins 62, 63
Maybe another USART on Pins 50,51, but that would require changing the code for talking to Servos from using USART3 to instead UART4 (the actual physical pins support both)

[KurtEck]

Not sure if anyone is interested, I extracted the alternate pin information from the processor manuals for the OpenCR and combined it with the Arduino pins information, to be able to see what functionality each physical pin has the ability to do...

OpenCR Pins.zip

[TXBDan]

Kurt, i'm thinking about getting a rovor as a platform to develop some ROS experience. Are you happy with the Turtlebot3? Would you recommend it vs more home made options? It's only real purpose would be for learning. No functional tasks are really necessary.