My first quadcopter build

In this post I will share my experiences with building a budget quadcopter I bought from AliExpress. This is by no means a tutorial and I advise you to look in the links section of this post if you are looking for a one.

So let’s begin.

It came without instructions, I messaged the seller and he/she replied that there are enough build instructions available

https://nl.aliexpress.com/item/Carbon-Fiber-Mini-QAV250-H250-C250-Quadcopter-1806-Brushless-Motor-12A-ESC-CC3D-Control-Board-5030/32285772418.html.

One problem though it came without instructions. I messaged the seller and got a reply similar to use google and RTFM. Not knowing where to go from there I shelved the project. Two weeks ago I decided to get over my self doubt and continue the project. After all how hard could it be right?

I started looking for tutorials online and found one which suited my needs.

http://www.dronetrest.com/t/qav-zmr-250-assembly-build-guide/1244

Although the overall proces seems simple the tutorial managed to confuse me quite a bit. The topics I got confused about:

Which length srew to use for the motors
How to connect the wires for the motors
How to orientate the cc3d board computer
How to connect the receiver to the cc3d

Motor screw length

This will probably vary on the types of motors but I ended up using 6 mm screws which I thought would be to long and might damage the motors. I tested it with one motor which continued to work. I decided what worked for one will work for all and fitted the 6mm screws on all motors. Please note that this does not mean 6 mm is the right fit for your motors.

How to connect the motor wires

According to the tutorial the wires for motors that turn clockwise have to be switched and the wires for the CCW motors do not need switching. Further along the tutorial it says the wire for the CCW motor needs to be switched. To be clear only the first statement is true (although this issue could probably be fixed in the firmware).

Orientation of the cc3d board.

The tutorial tells you to place the cc3d board with the arrow to the side (left) but instead this needs to point at the front of the copter. Putting the cc3d arrow to the left will make the computer think the side is the front of the copter which causes the copter to flip immediatly on takeoff.

After fixing these issues I was able to get my quad of the ground.

I’ve included the maiden flight below:

Note2Self #1:

buy a small drone and learn how to fly it.

Tried to fly the drone outside and crashed it :(.

Also one of the motor wires came loose and when testing for damage the ESC fried.

Note2self #2:

Do not remove shrink wrap from ESC’s or re apply if removed. Plus isolate the power pads on the power distribution board. The frame of the QAV250 is conductive and will create shorting causing all tons of fun like mini fires :D.

ToDo:

Get 4 new ESC + motor
Get a new smaller drone to fly indoors
Get a strap to fasten the battery

Saturday the 14th of october:

Got my replacement motors plus ESC’s in the mail. Also got my mini drone the day before. Those things are awesome and a good tool to learn how to fly a quad.

28th of January

So I rebuilt my quad just to find out one of my motors stutters. When searching for a solution I found several other people had this problem in combination with the cc3d and librepilot. One suggestion was to update the firmware on my simonk Esc (which of course are cheap ripoffs of the real thing). I looked at the pcb to find a fis 330 chip was there waiting for me. Supposedly these can be flashed with an arduino nano and blheli suite. So that’s where we are going next.

Flashing a BIOS chip with a Raspberry Pi

I made this post as a addition or supplement to my “Flashing a BIOS chip with an Arduino” post.

While doing some research online I found several articles/posts from people using a Raspberry Pi to flash SPI flash chips. Apparently the Raspberry Pi is very suitable for this kind of thing as it has a SPI interface and is able to run linux. I was eager to try this out for myself so I got out my Pi 3 model B and got to work. For this project I used a Winbond 25X80 salvaged from a motherboard I had lying around.

Preparing the RaspberryPi

I’ve tried different versions of Raspbian but Jessie lite seems to works best for me. It is available for download here: https://downloads.raspberrypi.org/raspbian_lite/images/raspbian_lite-2017-07-05/

Install the packages needed by flashrom by using the following command:

sudo apt-get install pciutils libpci-dev libusb-1.0 libusb-dev git

Build and install flashrom using the commands below:

git clone https://github.com/flashrom/flashrom.git
cd flashrom
make && make install

Before continuing we need to enable the SPI interfaces on the Raspberry Pi. This can be done either by editing the config file found at /boot/config.txt and uncommenting the line that says #dtparam=spi=on or by using raspi-config. Run raspi-config, and under interfaces enable SPI.

After rebooting the SPI interfaces are available under /dev/spidev0.0 and /dev/spidev0.1.

Connecting the Raspberry to the SPI flash chip

The table below show the connections between the RaspberryPi and the chip.

RPi pin	SPI flash
25	GND
24	CS
23	SCK
21	DO
19	DI
17	VCC 3.3V and /HOLD and /WP

In order to verify flashrom is working correctly and the chip is detected properly we run flashrom without any operation. Example output can be found below:

pi@raspberrypi:~ $ flashrom -p linux_spi:dev=/dev/spidev0.1
flashrom v0.9.9-91-g0bfa819 on Linux 4.9.35-v7+ (arm7l)
flashrom is free software, get the source code at https://flashrom.org

Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns). 
Found Winbond flash chip "W25X80" (1024 kB, SPI) on linux_spi. 
No operations were specified.

Now that we have verified everything is in order we can start writing the BIOS to the chip:

pi@raspberrypi:~ $ flashrom -p linux_spi:dev=/dev/spidev0.1 -w YOURBIOS
flashrom v0.9.9-91-g0bfa819 on Linux 4.9.35-v7+ (armv7l)
flashrom is free software, get the source code at https://flashrom.org

Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns).
Found Winbond flash chip "W25X80" (1024 kB, SPI) on linux_spi.
Reading old flash chip contents... done.
Erasing and writing flash chip... Erase/write done.
Verifying flash... VERIFIED.

And that is that.

Resources:

Testing for some issues with Raspbian Strech

Adding a YubiKey to Lastpass

In the beginning of this year I got a YubiKey NEO from a colleague. As I
was already using LastPass to manage my passwords I wanted use my YubiKey as part of the two factor authentication process.

You can register your YubiKey by going to the premium “Multi-factor options” in your LastPass account settings and enabling the YubiKey option. For the two factor authentication to work you need to press the button on the YubiKey to generate a OTP (One Time Password) which will be stored with LastPass.

When I tried this for the first time I ran into a problem and got the following error: “At least one of the YubiKey tokens provided failed to validate.”. Copy and pasting this error in Google led me to a post on the LastPass support forum in which the solution was provided.

Thank you for contacting LastPass Support.

You need to set your YubiKey configuration to OTP authentication mode:

http://www.yubico.com/products/services … bikey-otp/

Once that is done, visit the following URL: https://lastpass.com/debug.php and where it says ‘YubiKey with LastPass’, run the authenticator to make sure everything is working properly.

If no issues found, try to setup the YubiKey once again:

https://helpdesk.lastpass.com/security- … ntication/

Let me know how it goes.

Best,
Jed

After enabling OTP I could register my key and start using it with LastPass.

Updating the operating system on my Atari 1040STF

After finishing the drive swap mod on Atari 1040 STF I continued browsing the Atari forum’s hardware section and found a post/guide on how to update the operating software. In general, updating the OS is advisable as newer versions may contain bug fixes, security updates and increased I/O compatibility. The same goes for my Atari. The last available version for my machine, 1.04 a.k.a. Rainbow TOS, contains all of the above and is found to be faster overall.

On the Atari, the OS is stored on two or in my case six ROM (Read Only Memory) chips. As the name indicates, writing to ROM chips is not possible so they have to be replaced with chips containing the newer OS. While it is possible to buy a “ready to go” upgrade package it is also possible to go the DIY route and prepare the chips yourself. I opted for the latter as it is much more fun, educational and gives a real sense of achievement when finished.

Continue reading Updating the operating system on my Atari 1040STF

Fix wifi Acer Aspire 5040

I recently upgraded a Acer Aspire 5040 to Windows 7. After the upgrade I installed all the drivers and found the wifi was not working correctly. Everything looked fine but I could not see any access points to connect to. To fix this issue I had to go Acer’s support website and download and install the Launch Manager. Before installing I had to enable compatibility mode for Windows XP and select run as administrator on the setup.exe. After rebooting the lights on the front of the laptop turned on and I could now detect access points.

Sites used:

Flashing a bios chip with an Arduino

In this post I will describe how to flash a BIOS (SPI) chip using a Arduino Duemilanove. I first learned about this method after reading about it on hackaday. At the time I had a Asus P5B motherboard that suffered from a bad BIOS flash and needed to be recovered. I tried other methods before but found none were as easy as this one.

So lets get started.

The requirements

Hardware

Arduino Duemilanove (full list can be found here https://www.flashrom.org/Serprog/Arduino_flasher )
A flash chip that is supported by flashrom ( full list available here https://www.flashrom.org/Supported_hardware )

Software

Ubuntu 16.04 VM
Flashrom
Fser-duino

Preparing the environment

Installing Git and the dependencies needed for Flashrom and frser-duino:

sudo apt-get install git libpci-dev libusb-dev libusb-1.0 gcc-avr binutils-avr gdb-avr avr-libc avrdude

Compiling and installing Flashrom

git clone git://github.com/flashrom/flashrom.git
cd flashrom
make && make install

Preparing the Arduino Duemilanove

git clone --recursive git://github.com/urjaman/frser-duino
cd frser-duino
make ftdi
make flash-ftdi

The table below shows which pins on the Arduino should go to which pin on the SPI flash chip.

Arduino Pins	SPI Pins
12	SO
11	SI
10	CS
13	SCLK
3.3V	VCC +/WP + /HOLD
GND	GND

Flashing the SPI chip

To verify that everything is working correctly we first run flashrom without any operations:

tom@ubuntu-vm:~$ sudo flashrom -p serprog:dev=/dev/ttyUSB0:2000000
flashrom v0.9.9-91-g0bfa819 on Linux 4.10.0-28-generic (x86_64)
flashrom is free software, get the source code at https://flashrom.org

Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns).
serprog: Programmer name is "frser-duino"
Found Macronix flash chip "MX25L8005" (1024 kB, SPI) on serprog.
No operations were specified.

As can be seen from the above command output, both the Arduino and the SPI chip are detected. Now we can continue with writing the new BIOS to the chip:

tom@ubuntu-vm:~$ sudo flashrom -p serprog:dev=/dev/ttyUSB0:2000000 -w <NEWBIOS>

flashrom v0.9.9-91-g0bfa819 on Linux 4.10.0-28-generic (x86_64)
flashrom is free software, get the source code at https://flashrom.org

Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns).
serprog: Programmer name is "frser-duino"
Found Macronix flash chip "MX25L8005" (1024 kB, SPI) on serprog.
Reading old flash chip contents... done.
Erasing and writing flash chip... Erase/write done.
Verifying flash... VERIFIED.

And thats it, the new BIOS is written to the chip and all that is left is testing if my computer boots up again.

Resources:

HP ENVY SPECIFIC:

Sansa Clip+ Repair

My girlfriend was almost in tears when she told me her beloved Sansa Clip+ would not power on anymore. She handed me the little music player and told me that earlier that day, she pressed the power button a bit too hard after which she heard something break.

When inspecting the power button I noticed it was a bit loose where it usually has some tension from the switch underneath. I decided to have a closer look and used a tutorial to help me disassemble the Sansa.
Looking at the board the problem quickly revealed itself. The “extreme” use of force had broken the solder connections between the power switch and the board and as a result the switch fell off. Time to get out the soldering iron!

After reseating the switch and repairing the broken solder connections the Sansa powered up again meaning my girlfriend could listen to here favourite music again and dry her tears.

Edit: After a week my girlfriend returned to me with her Sansa. This time she was only hearing sound from one of her earbuds instead of both. Because I taught her well she had already tried multiple headphones to verify the problem was not the headphones but rather the Sansa itself. I did some research and found that this problem can be fixed by reheating the solder connections between the headphone jack and the board. It appears that the “stress” resulting from removing and plugging in the headphones weakens the connections.