A collection of note-to-self's
I recently bought the Phoenix R/C simulator. It comes with its own USB-cable to plug into your remote controller’s trainer cable. A friend of mine has a Spektrum remote, and the stereo 3.5mm jack plugs right is.
I have a Futaba FF9 remote, so they wanted me to buy the “adapter cable to FF9” for €16. Since I already had the pinout of the FF9-connector figured out, I figured I could make this cable myself.
When learning to fly my remote controlled helicopter I was also interested in the technical side. In this post I’ll write down what I discovered about the “air interface”.
In most (every?) countries, the use of the electromagnetic spectrum is limited by law. Some frequencies are almost universally reserved for public use (the 2.4GHz band used by e.g. WLANs). Other bands are highly restricted (the band around 120MHz, used for communication with real airplanes). In Belgium, the 35MHz band is reserved exclusively for model aircrafts. Other bands popular around the world are the 40MHz and 72MHz band.
Continue reading ‘Remote controlled aircrafts: the air interface’ »
A few months ago, I got the FlyCamOne2 as an add-on for my Raptor. The manual mentions that the recording can be started and stopped electronically. With some additional electronics, it should be possible to start/stop the camera from the ground using one of the free channels on my remote.
The free channel can’t be used directly: the receiver sends out pulses of different lengths (between 1ms and 2ms), while the FlyCamOne2 needs a simple short to start recording. Some electronics will be needed to convert between these two.
After some googling, I found the CurveRC FCO2 I/F which does exactly that. But there are some downsides:
The CurveRC print seems to be build around an Atmel Tiny25 microcontroller, which is an 8bit RISC processor with 2K of build-in flash. Using a microprocessor makes the design fairly simple since nearly everything can be done in software. However, it must be clocked at reasonable speed to do something useful. This explains the fairly high power consumption.
So I decided I could do “better”.
When learning to fly a remote controlled model, getting a good teacher is worth a lot. But if all the teacher can do is watch the plane crash, he/she is of not much use…
Most transmitters have a “trainer” connection. This allows two remotes to be connected together. One is preforming the master-role and is actually controlling the model. The other remote is the slave and sends signals to the master. The teacher can program his master-transmitter to copy some of the slave’s signals, thereby letting the student control the plane. A simple toggle of the switch returns the control to the teacher.
Obviously, each brand of transmitters has its own “standard” of doing things. Some use a DIN6 contact, others use a mono- or stereo 3.5mm jack and there is the obligatory “proprietary connector”. Here are my notes of the expedition into the trainer-cable jungle.
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