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Requirements for the NG Hardware

The following describes what you need to start construction of a UAVP Next Generation Multicopter.

Getting the needed PCBs

Check out the UAVP-NG Shop to order your NG PCBs.

Note

{i} The first NG boards have been released to the public on the 26. december of 2009! Newer hardware revisions can be found in the UAVP-NG non-profit Shop.

Getting the needed Firmware

Check out the Download page to find the needed files.

Note

{i} The NG firmware source code has been released as Open Source under a GPL license on december 30, 2010 and has been continiously improved since then!

Brushless Controllers

Currently there are at least four Brushless Controllers needed for the NG. The NG is able to support different propeller configurations where the number of motors varies and thus another number of Brushless Controllers could be needed. This is dependent on the HAL (Hardware Abstraction Layer) configured. Each bl-controller controls a brushless motor. Brushless motors don't use brushes for energy-distribution to the rotor. In contrary to the motors with brushes, the magnets are rotating while the coils are steady. That's why you can't use a DC current, an AC current with precise pulses is needed to drive the motors. This AC current is provided by the BL-Ctrl.

The NG supports different types of Brushless Controllers all of them using I2C to receive the control signal from the flight control.

Note
Be sure that the chosen Brushless Controllers will support the peak current needed by your chosen motors!
Note that support for different controllers is in different states of stability.
We currently advise to use our NGBLC-4mini, BL-Ctrl or China Controllers!

Currently supported Brushless Controllers are:

Be sure to check out the UserCopters page to find out proven combinations.

Brushless Motors

Theoretically all Brushless Motors can be used with the NG if the Brushless Controllers can supply the needed peak current.

The choice of the motor heavily depends on purpose and takeoff weight of your NG. Since a tri- or quadrocopter needs mainly stationary thrust and not a high maximum speed, it ideally uses slow running, big propellers with a low pitch. Impellers are generally not a good idea. To avoid gearboxes (weight, clumsy, inefficient, noisy) it is highly recommended to use brushless outrunner motors with a low "kv" (RPMs per volts, about 1000kv are fine) rating. The revolutions per minute should be in the range of 3000 to 4500 when hovering.

Rule of thumb:

3s LiPo Battery:

8" Prop -> ~1200-1400kv, ~25-30g

10" Prop -> ~1000-1200kv, ~45-55g

12" Prop -> ~800-1000kv, ~65-75g

4s LiPo Battery:

8" Prop -> ~1000-1200kv

10" Prop -> ~800-1000kv

12" Prop -> ~750-900kv

Some of the used Brushless Motors are:

Our NGBLC-4mini also supports most of the above mentioned Brushless Motors. Other combinations should work, but need to be tested.

Be sure to check out the UserCopters page to find out proven combinations.

Propellers

You should choose propellers to get the same thrust as the takeoff weight at about 3000 to 4500 RPMs. If propellers are too small, the RPMs will be too high, and efficiency and payload weight suffers. Also, flight time will decrease significantly, because of too high current consumption. If propellers are too big, the hovering RPMs are too low, so flight stability suffers. Unfortunately, the availability of CW and CCW propellers is limited. A good choice for NGs up to ~1.5 kg takeoff weight are the well known black EPP1045 (10" x 4,5"). There are also the EPP1245 and EPP0845. APC delivers CW and CCW propellers as well, you may test the 10"x4.7", 10x3.8" and 12"x3.8" props. If you have really strong motors on a small frame you could also go for the GWS 9x5" 3-Blade Prop thats available in CW and CCW. Graupner has 10"x5" CW and CCW propellors that are very strong. The Graupner props need a higher KV engine than the EPP1045 propellors (around 1000KV).

Be sure to check out the UserCopters page to find out proven combinations.

Frame

There are almost no borders set for your fantasy. The motor-motor distance can vary between 35 cm and 60 cm, depending on motor and propeller size. It is advisable for beginners to start with a standard 35cm to 40cm frame of 10mm aluminium square profile.

To build a simple Quadcopter frame you need some square aluminium rods and a bit a GFK or CFK as a center plate. There are commercial frames available also. Use Google to find them.

Be sure to check out the UserCopters page and the CAD page to find proven combinations and CAD files, such as centerplates for your mill.

Cabling

Depending on your chosen motors the cabling of your NG will have to use different cable diameters. If you are about to buy cables take 2.5mm², 1mm²,(0.75mm²), 0.25mm² and 0.14mm²

LiPo Battery

As batteries usually Lithium-Polymer batteries or LiPos are used. These types of batteries differ from other types by a light weight combined with high capacity. Handling these batteries is not without any danger, so some rules have to be kept in mind. These types need a special kind of charger, because the charging procedure differs a lot from other types (like NiCad and NiMh). The cells should not be overcharged, neither should they be unloaded too deeply! Make sure that you disconnect your battery from your NG everytime!.

To keep the charge difference between cells to a minimum, a balancer must be used. This balancer might be integrated in the charger, or a separate balancer should be attached to the charger. All LiPo-packs have a connector for a balancer.

For a Quadcopter LiPo-packs with three or four cells are used. They have a voltage of 11,1 V or 14,4 V. Depending on your chosen Brushless Motors you will need a bigger or smaller battery. Normal sizes are 1200mAh/20C to 5000mAh/30C batteries.

If you wonder about the differences of a 3S and 4S LiPo copter be sure to check the FAQ entry Difference of 3S and 4S copters.

There is also a new variation of the LiPo battery gaining momentum in the RC scene. The new LiFePo batteries made by A123 Systems have some advantages over the classic LiPo chemistry, like higher cycle life, temperature operating range and fast charge capability up to 5C, which makes it possible to charge a pack in about 10-15 minutes! Those benefits come with a small drawback, the energy density being a bit lower compared to the classic LiPo chemistry. Practically, there's only one cell type available at the moment, which you can buy in packs from RC hobby suppliers. Make sure that you get a 4S pack as the nominal cell voltage (3.6V) is lower than the usual 4.1V.

RC Receiver

You will need one or more RC Receivers. We support one RC Receiver using a sum-signal.

Furthermore we support the ACT DSL protocol on two UARTs on the RC controller and on the two UARTs on the LPC. This means ultimatly you can attach 4 DSL receivers at the same time. Since DSL controllers also support RSSI signal quality, different mixing features are supported when multiple DSL receivers are attached. You can do Teacher/Student and Diversity when two DSL receivers are attached.

Additionaly it's possible to switch the sum signal input to the S3D sum-signal used by the ACT S3D XS2+4 2.4GHz receiver available from ACT.

Beside the above we also support the Graupner HOTT receivers (SUMD), Spektrum as well as Multiplex receivers.

Serial Level Converter

To easily use the NG's UARTs it's best you get a SerCon. It allows to attach the UARTs of your NG to any PC RS232 port. Another option would be the USB to UART/3.3V level converter like USB-zu-RS232 Wandler from Embedded Projects.

JTAG Programmer

If you intend to flash your NG's LPC2148 regularly with a new firmware you probably want to have a JTAG adapter. With it you're able to flash the LPC2148 on the NG using its JTAG Interface instad of having to use the serial interface to serial flash it. The big difference is the speed. Using the JTAG interface you're able to flash the NG within seconds whereas this takes two to three minutes using the serial interface. In addition, you can use the JTAG adapter for in system debugging of the software. The JTAG Page has more Information about using the JTAG interface.

We made good experiences using the Amontec Tiny JTAG Key. It's cheap and does its job. The Olimex ARM-USB-TINY has also been reported to work on the LPC2148 headerboard.

ISP Programmer

For now we use the AVR Dragon and the AVRISP mk2 to flash the two Atmels (rc-controller on the FC and sensor-board controller), but anything that is able to do ISP programming of the Atmels with 3.3V and 5V target VCC will work.

We intend to extend the NGOS to make it able to flash the two Atmels using a special bootloader which allows to flash from the LPC2148, but that's not yet implemented.

Electronic Components

The Part Lists page describes in detail which electronic components you will need.

Documentation/Requirements (last edited 2014-01-22 12:27:20 by AmirGuindehi)