Today I’ve got the chance to get my hands on a Leap Motion. As it uses depth information to track hands on a short range from the device and as there is a ros driver package existing for it, I hoped to get a 3D PointCloud. It costs about 80€ and could have been a cheap replacement for the [amazon &title=Xtion&text=Asus Xtion].
Unfortunately its not possible (yet?) – here is a very nice post why.
But it is fun anyways to get both hands tracked:
LeapMotion – Infrared 1
LeapMotion – Infrared 2
LeapMotion – two hands, 10 fingers
The ros driver interfaces ros with only one hand – but we could do something like shown below to control the amosero:
Later it would be a nice way to control a robot arm – but for now we leave that nice little device as there is a lot of other stuff to be done.
For reasons of documentation and because I never did something like that before (fun) I have created a little video of the amosero driving around in the yard today. It is my longest video so far and I hope you enjoy it:
I’ve connected the [amazon &title=Raspberry Pi&text=Raspberry Pi] to an L298N and two 6V DC Motors, which have been in the Makeblock Starter Kit. I’ve had some issues with the WPA2 Enterprise TLS Network, which is why there is an cable attached.
I’ve also written a small geometry/Twist controller for ROS-compatibility,for controlling the robots movement with keyboard interop like I did before.
Before I dismantle this little robot, I’ve like to share a little video:
As soon as possible I will use the arduino micro and the two 250rpm stepper motors – for that I am planning to use a Arduino Motor shield that I’ve already ordered.
Today I experimented with a 12V bipolar stepper motor and the 5V arduino micro.
To get things working I’ve put the 9V from my six 1.5V Batteries into an UBEC which accelerates them to 12V at a loss of below 10% (at 350mAh) connected them to the VCC of the L298N and wired the 4 signal cables of the motors to it. Because thats a lot of numbers to keep track of – I’ve made a small video of the setup:
Doing the math according to a wheel with 5,8cm heigth and 150rpm I’ve reached, my robot will be able to run about 1,6 km/h – this might be increased with a better motor driver like they used on the arduino motor shield. I’ve read they reached about 250 rpm on the same motor which would be 2,73km/h.
The code of the arduino is pretty simple:
constintstepsPerRevolution=200;// change this to fit the number of steps per revolution
So before trying to get the planned stepper motors running, I quickly put a dc motors setup together:
The fully wired l298n
arduino micro supporting 5V and IN1,IN2,IN3,IN4
I’ve got two dc motors coming with my make block robot starter kit. And for research I also ordered a small l298n motor controller shield which is able to control motors up to 24Vs and 2A each by 4 small input wires at for example 3,3V and 2 additional +5V motor enablers.
There is a nice little page which explains all states of the L298N according to the arduino micro here. For a [amazon &title=Raspberry Pi&text=Raspberry Pi] I found a nice Youtube video explaining everything here.
For me in the end both motors rotated quite nicely, like this video shows: