Entry #2 - A Glossary of Drones

One of the biggest obstacles to a newbie like me to the world of drones is the terminology and TLAs that are so freely used.

Before discussing anything else I'm going to start a glossary here.

If I achieve nothing else other than publishing a basic glossary of the vocabulary of drones I think I will have achieved something useful to someone, because I have not yet stumbled accross a good glossary.

If you know of other good glossaries, post a comment and I'll link them in if I think they are any good.

One thing to remember is that the language of drones inherits from other languages, communities and cultures. Radio Control model enthusiasts, Computer Hackers, radio hams, electronics geeks have all contributed to this

If there's an error on this page (in fact on this whole blog) please let me know.

Glossary

• Accoutrements - accoutrements are additional items of uniform, dress or equipment. E.g. cables, tools radio neck straps etc. Every hobby or field of human endeavor has them and they are often a big part of the fun.
• Balance - most LiPo batteries used in quads have two leads, one for delivering power, known as the "Discharge" plug and one used by a charger or battery gauge to monitor the charge level (voltage) of each cell.
  This latter cable is called the Balance cable/lead.
  The balance lead is also used for adding or removing charge to bring all the cells in a battery to the same voltage. This process of equalising the voltage in the cells is known as balancing the battery.
  The balance lead is sometimes used as a secondary power connector to power low draw devices.
  The balance lead normally has a ground wire and a single wire for each cell.
   i.e.  a 4S battery's balance lead will have 5 wires. The balance lead wires are much smaller gauge than the discharge lead.
• Balance Charging - techniques used to enhance battery performance and extend battery life by making sure each cell in the battery is charged optimally.
• Baseflight - an Opensource flight controller distribution. Basically the firmware for a wide range of flight controller.
• BEC - Battery Eliminator Circuit - in FPV this is really a voltage converter it takes higher voltage (e.g. 9-16v)  and converts it to a lower voltage e.g. (3.3-5v) so that you can use a single battery for both powertrain and flight control.
  BECs tend not to be separate components now, but instead are often built into the ESC's, the PDB or the flight controller itself.
• C - 'C' is used as a unit for describing LiPo battery performance. It literally stands for "capacity" but is used to described the safe sustainable draw from the battery in terms of its capacity. You can draw C multiplied by the battery's capacity p from a battery per hour (because the unit of capacity was ma/h - milliamps per hour).
  
  So for a 2000ma/h battery with a C of 20 you can safely draw:
  ( 20 x 2000ma/h) = 40,0000ma/h or   40 Amps from that battery per hour.
  To get the amps per minute we divide by 60 and get 0.666A/h or 666 ma per minute, so you'd get about 3 minutes at max safe draw from that battery.
  
  See http://www.rchelicopterfun.com/rc-lipo-batteries.html for a way better description.
• Cleanflight - a "fork" of Baseflight. I.e. another project that releases firmware for a variety of flight controllers Said by some to be more frequently updated and to have been re-factored to be easier to maintain and add new features and architectures to. I'm not familiar enough with the politics of the fork or the code to know the veracity of either side's claims.
• Configurator - a piece of software for configuring a flight controller's parameters.  E.g. the re is a Cleanflight Cofigurator and a Baseflight Configurator It is not uncommon for modern configurators to be Chrome apps that can be run on any Chrome browser that support Chrome apps. This is awesome as it means Windows, Linux and Mac as well as a number of other devices are all able to configure many flight controllers.
• Discharge plug/Lead - the type of connecter that a battery has to supply power to the device it is powering (e.g. your quad). Typcially in FPV this will be a XT-60, however it is possible to buy some batteries with different discharge plugs (e.g. Dean's connectors) so when you buy batteries you need to check that they have the correct Discharge Plug.
  The discharge lead is the lead that connects the discharge plug to the battery. The discharge lead will usually be around 12-14AWG. It is recommended that the battery lead on the quad be at least the same gauge or larger as the discharge lead of your most powerful battery.
  See also Balance.
• ESC - Electronic Speed Controllers - these control the amount of power that a motor can draw based on commands from the FC
• FC - flight controller - the computer and sensors that control the flight of the drone by varying the power each motor can draw via the ESC.
• FPV - first person video or view - a camera  mounted on a drone and associated systems that allow the pilot to see the camera output and use it to control the drone. To the pilot it appears they are seeing from the drone's perspective.
• GPS - Global Positioning System - a US DOD satellite navigation system that has been made publicly available.
• JST - Japan Solderless Terminal - the little white "plug" pairs that are used to attach some devices. There are many different types of JST, e.g. JST-H. The differences include the "pitch" (distance between pins), the keying and other physical/design characteristics.
  Often in RC a single JST port will provide several functions, e.g. there might be a serial port on 4 of the pins and the hardware debugging pins on the remainder.
• Kv - constant (K) of revolutions per volt (v). The revolutions per volt per minute a motor is rated at.
  E.g. a 2000Kv motor running on a 3S  (11.1V) battery would generate up to 22200RPM (3 x 11000). This is the rated speed of the motor with no load i.e. no prop.
• LiPo - Lithium Polymer - the battery technology used for electric flying machines. LiPo batteries have a good energy density which makes them useful for flying machines. They have downsides too, like than can catch fire and explode easily, so much so that you need to be really careful when taking them on commercial flights and disposing of them. You should research LiPo Battery Safety if you don't know much about them. This site seems to have pretty decent info: http://www.dronethusiast.com/ultimate-drone-battery-care/
• Meaning of life - he who dies with the best toys, wins.
• Molex - a company that manufactures connectors such as power and signal connectors for wires. Used generically Molex usually means a (usually) plastic connector.
• MSP - Multi Wii Serial Protocol - the protocol used to configure many flight controllers running Multii Wii derived/forked code, such as Cleanflight, Betaflight etc. This is how your FC talks to your computer over the USB port. 
• OSD - Onscreen Display - displays an information overlay like a HUD onto the video stream from an FPV rig. In some cases can be used to change or tweak parameters on the FC without a computer.
• PDB - Power Distribution Board
• PWM - Pulse Width Modulation - a relatively simple protocol used to control things. In RC PWMs is used to be on of the protocols used to transmit info from a radio reciever to a flight controller, though that is less common now. The common use of PWM in RC these days seems to be for the flight controller to communicate with the ESC.
  PWM requires exclusive use of a channel for each datastream (or control signal), so you need a wire between each ESC and the flight controller.
• PPM - Pulse Position Modulation - a slightly more complex protocol similar to PWM. PPM's advantage is that multiple signals can be multiplexed onto a single channel, so you can use less wiring (and less channels if your sending over RF) to control a number of datastreams/control signals over a single channel/wire.
  PPM is commonly used to connect flight controllers with radio recievers
• RC - Radio Controlled -
• RX - receive or receiver
• Receiver - normally in RC the receiver refers to the RC radio receiver that your transmiter sends the control signal too. In FPV receiver can also refer to the radio receiver that the VTX sends the video signal to.
• S - 2S, 3s, 4s, etc - 'S' is a the nomenclature system for  the number of cells in LiPo batteries. A battery has the number of cells equivalent to it's S rating. I.e. a 3S battery has 3 cells, a 4S battery has 4 cells.
  Each cell is nominally rated at 3.7volts, so the S rating is also a way to judge voltage, i.e. a 2S battery should supply about 2 x 3.7v, i.e. 7.4v, a 3S battery should supply about 11.1v (3 x 3.7v) etc.
• Satellite - a satellite receiver is a small flight control radio receiver. It is not related to GPS or satellite navigation.
• Signal - a signal is a way of transmitting or transporting some form of information. For the purposes of RC there are two main types of signal, analog or digital.
  A signal is usually sent by modulating - that is changing - the magnitude, duration or frequency of a wave or stream of energy (e.g. light for fibre options, RF for radios, electrical charge for wired communications).
  How the modulation of the energy stream or wave is interpreted defines if it is a digital or analog signal.
  I will not try to explain how signalling works - to be honest I have only  very basic theoretical understanding and that depth of understanding is not required to build and fly a quad. Though it might be really useful to tweak the heck out of one.
  In RC the information that a signal carries is usually a "command" to signify that the flight controller should perform some operation (e.g. increase throttle) or telemetry info that relays the state of the drone back to the pilot.
  The FPV there is also the video signal that carries the image the camera sees to your goggles/screen
• Soft Serial - a method of getting the benefit of extra serial ports without having extra circuitry. The hardware for a soft serial port is emulated in software and an unused pin pair (often an unused PWM pair) is used to connect the device too. Use of speed rates above 19200(?) not recommended.
• TX - transmit or transmitter
• UART - Universal Asynchronous Receiver/Transmitter - a UART is basically the same as a computer's serial port (On a computer a serial port is some times referred to as a COM port.).
   A UART can be used to attach and communicate with peripherals to your FC. Not really all that surprised since the FC is just a little computer with some sensors attached. Examples of peripherals include the RC recevier, OSDs, some VTXs to allow them to be controlled via the OSD, data loggers and the like. 
• VTX - Video Transmitter - takes the signal from the on board (FPV) camera and transmits it to the pilot's (and anyone else's) receiver.
• XT-60 a widely used electrical connector rated at 60A. Pretty much the standard discharge connector for batteries in FPV.