The second quadrocopter is a lot easier to build. The whole world of quadrocopter and radio controlled model making in general was very new to me. I made wrong decisions or just didn’t know how I want to have it in the end… Here is a small lists of improvements I made on my second quadrocopter. It might help other beginners to do it better in first place

Battery connectors

XT60 plugs

On my first copter I bought the same connectors for the quadrocopter which the batteries had: 4mm Bullet connectors. But connecting them was dreadfully: My connectors were a little bit to big, so I had to deform the plastic of the connectors a little bit. The plastic on the front was battered. Connecting them was very tough, in the end I didn’t connected them fully, it simply wasn’t possible anymore. So it was time to switch. I decided to use the XT60 connectors from Hobbyking (an alternative to the popular Deans connector system). They are cheap and you can also buy batteries with this connectors. The connection holds strong but you can connect and disconnect them without problem. No more half connected plugs in the air.

Power distribution

Power distribution

New landers: Claws

Landers and centerplate

Having good landers from start is also very convenient. Starting from grass is no problem, calibrating the acceleration sensor is easier too. I already wrote about my new centerplates. They look good and are very strong.

LED’s

Its easier to distinguish the front of the quadrocopter with colored LED’s. I planned to add LED’s to my first copter already, but because the power distribution was inflexible I desisted installing them. On my second copter I bought 3mm plugs to connect them, and also added a cable to the power distribution system.

Bus Pirate

As I wrote yesterday I bougth the Bus Pirate from Seeedstudio and a nice case. Another team member found this nice tool. It can be used to prototype and test electronic deviecs with buses such as UART, SPI or I2C. As I saw the ability to work as an AVR programmer and even a JTAG adapter I was persuaded of it as well. It looks like a perfect devleoper device for the NG UAVP.
With delivery I paid about 55$ for both parts. The case from US arrived way faster then the Pirate itself from China, but finally both made their way to Switzerland! I needed to alter the case with a nail file a little bit to make sure the USB connector has enought space. Built into its case it looks very nice!
The firmware on the delivered device was not that up to date:

HiZ>I
Bus Pirate v3 (Seeed Studio)

http://dangerousprototypes.com

Firmware v2.4-Seeed
DEVID:0x0447 REVID:0x3043 (B5)

First I had to upgrade to V4 Bootloader. I connected the PGD and PGC pins of the ICSP header to trigger the bootloader. Then I changed bitrateindex to 8 (for 115200):

vi P24qp.ini

bitrateindex=8

Afterwards I could do the firmwareupgrade (just ignore the verification errors in the output, its a bug in v2 bootloader):

$ unzip v2tov41-bootloader-update-va3.zip
$ cd upgrader
$ sudo python P24qp.py --serial=/dev/ttyUSB1 -v --auto=BPv3-v2blupdaterVa3-v4.1.hex
....
Writing 256 bytes to address 0x0000AB80
Reading 256 bytes from address 0x0000AB80
Write operation complete.
Verified Okay.
Verification complete, switching to user mode

Now I removed the jumper and restartet the Bus Pirate. Pressing enter produced this output:

Upgrade cancelled.

Universal DS30 Loader installer v0.3 (C)hris 2010

Released under Creative Commons null license.
Found bootloader v unknown (probably v2)
Will install bootloader v4.1

Type 'Yes' to program the new bootloader.
Disconnect power if unsure (no harm done).

“Yes” started the upgrading

Erasing 0xA400... done
Erasing 0xA800... done
Writing row 0 1 2 3 4 5 6 7 done
Erasing 0x0000... done
Writing row 0... done

Success!
Upload new firmware with the ds30 Loader app to complete the upgrade.

When the update is complete, the MODE LED will blink and the upgrader will prompt you to upload a v4+ firmware. I connected the PGD and PGC pins of the ICSP header to trigger the bootloader once again and restarted the Bus Pirate. I then uploaded the v4.2 firmware directly (you can’t install the v4.2 bootloader since its only a version for programm with PIC directly):

$ unzip BusPirate.firmware.v4.2.zip
$ sudo ./pirate-loader_lnx --dev=/dev/ttyUSB1 --hex=BPv3\&v2go/BPv3-Firmware-v4.2.hex

Removed the jumper again and the Bus Pirate has a shiny new software version on it:

HiZ>I
Bus Pirate v3
Firmware v4.2 Bootloader v4.1
DEVID:0x0447 REVID:0x3043 (B5)

http://dangerousprototypes.com

AVR programmer (STK500v2)

One of the features I needed most was the AVR programmer. For that purpose you have to flash a special firmware:

$ sudo ./pirate-loader_lnx --dev=/dev/ttyUSB1 --hex=BPv3\&v2go/BPv3-STK500v2-v0b.hex

Afterwards you can use it like an STK500v2:

$ avrdude -p m328p -c stk500v2 -P /dev/ttyUSB1 -v -V -U flash:w:sb-ctrl.hex

Just a small performance comparission showed positive results. I wrote an Intel hex with 30178 bytes to an Atmel ATMEGA328P. These are the flash times:

Note: These are both out of the box configuration, with correct STK500v2 configuration you can probably gain more performance…