Robotic Arm controlled by patients mind
Previously I’ve wrote about monkeys with a brain implant that allowed them to move robotic arms. I had no doubt the next step would be to restore some freedom to paralyzed humans. Today in Nature it was published an article about a research that involved human patients with similar implants to the ones used in the monkeys.
After a practice period, in which scientists would operate the arm and monitor brain patterns of patients, they were able to control a robotic arm with a good success ratio (62% in grasping objects).
This are indeed great news for the robotic community and specially for people with mobility issues (paralyzed, elderly, etc) who in a near future might be able to have much more freedom and perform tasks that where impossible just a few years ago.
In the Nature Video a stroke patient successfully grasps a bottle:
ShareFlock of robots
It’s been a while since my last post, busy times, but this I had to show. This small nano quads have a precision and an agility that is worth seeing.
ShareUsing LV-MaxSonar-EZ Sonar with Picaxe
Recently I’ve had to develop a circuit using a picaxe 08M2 with MaxSonar-EZ1, and had a bit of difficulty understanding the output values from the sonar analog pin. Although the sonar have a really cool manual that comes in the package, it was still a bit confusing, specially if you don’t read the bellow quote carefully.
"Outputs analog voltage with a scaling factor of (Vcc/512) per inch. A supply of 5V yields ~9.8mV/in. and 3.3V yields ~6.4mV/in. The output is buffered and corresponds to the most recent range data"
It’s quite straightforward, but can be a bit confusing because the analog reading from picaxe is 0-255 range, which means 5v/255
The code for picaxe would be something like this:
main: readadc C.1, w1 debug w1 goto main
and the board would look like this:
When is all connected in the debug window you’ll see some values of w1 in the 0-255 range, so by using math rule of three, being X the sonar output voltage :
which is the same as:
example being w1 = 3:
So the output is 0.059v, but we know that 1 inch is vcc/512 (in this case vcc = 5v , but could be 3.3v) so is 5/512 (0.0098) and not 5/255 like what we got. So we do again a simple rule of three:
So we get 6inches which is the minimum value readable by the sonar. If we need centimeters we just multiply by 2.54 and get 15,3cm.
so the code will be something like this:
symbol range = w1 main: readadc C1, range range = range*5/255*98 'range = range*254/100 'convert to cm debug range
The values will be different mainly because we are working with integers here, so everything is rounded up.
Don’t forget that if your vcc is 3.3v you should change the constant 5 to 3.
ShareLight Sensitive leds
A few months ago I wrote a post with some light sensitive headlights for project .netRC, now I had time to implement the circuit on a prototype board to apply it to my new project. Here are some pictures and a small video. To check the circuit and code follow this link
And a small video of it in “action”:
Once again, the code and circuit in this link
ShareQuadroCopter Tenis…
When I think they won’t do anything else with the quadcopters, they decide to put them to play some sort of tenis…
This is in the Flying Machine Arena in Zurich and they really do awesome stuff there… check the video below:
Share

