If you have lots of RC creations about, each with their own receiver, you’ll know that the cost of a new one for each project can quickly mount up – despite RC receivers being pretty cheap these days. What if you could use a NRF24L01+ module costing less than $3?
That’s just what [Rudolph] has done for his Hackaday Prize entry, rudRemote. Though many people already spin their own RC link with the NRF24 modules, this sets itself apart by being a complete, well thought out solution, easily scalable to a large number of receivers.
The transmitter can be made of anything to hand; stick an NRF24 module and Teensy inside, some gimbals if needed, and you have a rudRemote transmitter. Gaming controllers, sandwich boxes and piles of laser cut parts are all encouraged options. [Rudolph] used some 40-year-old transmitters for his build – on the outside they remain unchanged, apart from a small OLED and rotary encoder for the function menu. The gimbal connections are simply re-routed to the Teensy I/O.
The protocol used is CRTP (Crazy RealTime Protocol); this is partly because one of the things [Rudolph] wanted to control is a CrazyFlie quadcopter. It’s a protocol that can easily be used to control anything you like, providing it fits into the 29-byte payload space. The CrazyFlie only uses 14 bytes of that, so there’s plenty of headroom for auxiliary functions.
We’d be interested to see the latency of this system – we’ve some surprising results when it comes to measuring cheap RC transmitter latency.
Last week we gave away a few Crazyflie 2.0 quadcopters to some cool Hackaday Prize entries. This quadcopter ships with the intention of being controlled by your smartphone. But it can also be controlled by a PC with USB dongle and an nRF24LU1+ SOC. [ajlitt] didn’t figure out he wanted the USB dongle (the Crazyradio) that can control this quad until after he used his gift code to claim his Crazyflie quad. No matter; the dongles for Logitech wireless keyboards and mice use the same radio as the Crazyflie and can be modded to make this quad fly.
The board inside the Logitech unifying receiver is a simple affair, with some pads for the USB connector, a crystal, the nRF24LU1+ radio module, and a few passives. To get this radio chip working with his computer, [ajlitt] simply needed to break out the SPI pins and wire everything to a Bus Pirate.
Getting the Crazyradio firmware onto this proved to be a little harder than soldering some magnet wire onto a few pins. The chip was first flashed without a bootloader, a full image with the bootloader was found, after wrangling a single byte into place, [ajlitt] had a working Crazyflie radio made from a wireless mouse dongle. The range isn’t great – only 30 feet or so, or about as far as you would expect a wireless mouse to work. Excellent work, even if [ajlitt] is temporarily without a mouse.
The Crazyflie 2.0 is available from the Hackaday Store, along with the add-ons if you don’t want to hack your own.
The gang at Bitcraze is at it again, this time developing Leap Motion control for their Crazyflie quadcopter, as well as releasing a Kinect-driven autopilot proof of concept. If you haven’t seen the Crazyflie before, you may not realize how compact it is: 90mm motor to motor and only 19 grams.
As far as we can tell, the Crazyflie still needs a PC to control it, so the Leap and Kinect are natural followups. Hand control with the Leap Motion is what you’d expect: just imagine your open palm controlling it like a marionette, with the height of your hand dictating thrust. The Kinect setup looks the most promising. The guys strapped a red ball to the Crazyflie that provides a trackable object against a white backdrop. The Kinect then monitors the quadcopter while a user steers via mouse clicks. Separate PID controllers correct the roll, pitch and thrust to reposition the Crazyflie from its current coordinates to a new setpoint chosen by a click or a drag. Videos of both Leap and Kinect piloting are below.
Tight on cash but still want to take to the skies? We have two rubber-band-powered devices from earlier this week: the Ornithopter and the hilariously brilliant GoPro Slingshot.
Continue reading “Crazyflie control with Leap and Kinect”