HOUND – SUGV prototype
Dronetech, a startup in which I’m involved is prototyping a new type of SUGV. This is an early sneak peek of what we are working on:
The video shows an early stage where we tested the mechanical components with the barely minimum electronics.
The full product will be available in the last quarter or 2013 first quarter, more news on the next weeks.
Dual Servo 180º Travel Expander
For all the FPV aficionados that don’t want to buy expensive digital servos, we have developed a servo travel expander that is dual channel and with a very small footprint so it won’t interfere with the model.
This product has a dual channel, and built in cable extender can be bought here dronetech store or in our ebay listing . For more informations contact us via Dronetech website
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:
Flock 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.
Using 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.