Soldering AWG10 wire to XT60 connector

If you need more flight time, more battery capacity helps (to some extent) ๐Ÿ™‚
But most batteries are designed for very high current, wires and connectors are also choosen for this purpose.
It’s sometimes a problem. I use in my tricopter standard XT60 connectors as it’s amperage is good enought for this purpose. When I used 1800-2200mAh batteries it was ok, as there come also with XT60.

When I bought 4000mAh with HXT4mm connector, I also bought adapter from HXT to XT60 for it. Problem solved.

Soon 4000mAh was not enought for me ๐Ÿ™‚
So, I bought 5000mAh, but this battery comes with 5.5mm bullet connectors. This time I decided to change connector to XT60 instead of messing with heavy adapters.
On Polish R/C forum there is a thread about such changes and most difficult thing for people is to solder XT60 to much thicker wires. My new 5Ah battery have 10AWG wire, so it’s quite thick. There are some ways for soldering these wires and I also have one.

Because ‘seeing is believing’ or ‘a picture is worth a thousand words’, I recorded how I solder such thick wire to XT60 ๐Ÿ™‚

What you need to make it:

  • tin ends of wire (mine were already tined as I desoldered old connectors instead of cutting it off)
  • turn pins in XT60 in opposite direction (you could use flat pilers to do it)
  • use ‘third hand’ – it’s very handy and also heat resistant
  • solder one wire at a time – it’s for your safety – don’t get a chance for short circuit
  • put tin into connector
  • put soldering iron into tin in connector and put wire there – this way area of heating is increased, so it’s easier and faster to do it
  • don’t hold wire in bare hands – use pilers, beacuse of heat
  • little patience depending on power of your soldering iron (mine have 65W) and experience

Good luck ๐Ÿ™‚

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LCD88 – going public :-)

Last days I was learning how to use git instead of svn ๐Ÿ™‚

I think it was worth to migrate LCD88 code from my personal repository to more public place, Github!
So, any further development will be there, I hope that it will be not only for downloading, but also you can contribute to project.
If you can’t code, there is also issue tracker, so you can request new feature, or simply report a bug. Starting forum threads is also planned ๐Ÿ™‚

During repository move GPL license was also added, so feel free to use this code.

Repository url: https://github.com/majekw/lcd88

Another thing I’m making is separate part of my site dedicated only to LCD88. Someone could call it ‘documentation’ ๐Ÿ™‚
Explore new menu item LCD88!

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XEBOOT – tiny Amega8 xmodem bootloader

Story

Few years ago I was working on some commercial device based on Atmega8. One of features was to deliver device with some software, but it should’ve been ready for further firmware updates by customer as well.

Burning some ready-made bootloader with STK or other proprietary protocol was not an option. Customer had only serial port adapter and that’s all. Operating system also could vary.

There was also another problem – device was quite simple, most of it’s power was in software. So, new firmware released to customer shouldn’t work with 3rd party hardware.
That way encryption was another ‘must be’ option for bootloader.

And last requirement – size. Program had some quite large tables burned in, so spending 2kB or more on bootloader was a waste of precious flash space.

So, I wrote bootloader myself ๐Ÿ™‚

Last days I decided to release this code to public as after all these years there is still no small xmodem bootloader available and now I could do it.

Features

  • small size (less than 512B)
  • supported protocol: xmodem
  • pure serial operation (no other hardware or wiring than rx/tx is required)
  • support some kind of encryption (not strong, but it’s enough to prevent unexperienced user to just burn it into clone)
  • it’s free (GPL v3) ๐Ÿ™‚

Code

You can download code from Github: https://github.com/majekw/xeboot
Technical details are also available in README on repository.

Fork

Yes, project evolved ๐Ÿ™‚
It was forked to support Atmega88/168/328. I had to sacrifice encryption to fit it in 0.5KB, so it’s no longer xEboot.
Fork is currently part of my other project LCD88 (diy r/c transmitter) and sources are also available on Github repository: https://github.com/majekw/lcd88

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RTL-SDR and ADS-B

I was searching Internet about FLARM and other possibilites to track small aircrafts, and how to use it in airplane models ๐Ÿ™‚
Of course, I found another interesting thing which reminded me that USB DVB-T tuner with well known Realtek RTL2832U could be used as ADS-B receiver.
In short, ADS-B is some kind of beacon transmited by most larger aircrafts. Protocol is well described, so everyone who could receive such signals could also decode it and do something with it. Most known site using these data is flightradar24.com.

Simple ADS-B receiver application (rtl_adsb) is already included in rtlsdr library, but it outputs to console only received packets with at most brief protocol decoding. Because my old tuner with FC0013 can’t receive 1090MHz, so during testing new one I forgot to check this.

dump1090 by antirez

But today I found quite impressive software to receive and visualize data: dump1090 (https://github.com/antirez/dump1090) and I had to check it:-)

It compiled flawlessly with just a ‘make’.
Running it without any options gives similar results to ‘rtl_adsb -V’, so nothing special here ๐Ÿ™‚

$ ./dump1090
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000001 (currently selected)
Found Rafael Micro R820T tuner
Max available gain is: 49.60
Setting gain to: 49.60
Exact sample rate is: 2000000.052982 Hz
Gain reported by device: 49.60
*8d471f4e9941f28fa8948de31fa4;
CRC: 000000 (ok)
DF 17: ADS-B message.
  Capability     : 5 (Level 2+3+4 (DF0,4,5,11,20,21,24,code7 - is airborne))
  ICAO Address   : 471f4e
  Extended Squitter  Type: 19
  Extended Squitter  Sub : 1
  Extended Squitter  Name: Airborne Velocity
    EW status         : Valid
    EW velocity       : 497
    NS status         : Valid
    NS velocity       : -124
    Vertical status   : Valid
    Vertical rate src : 0
    Vertical rate     : -2304

*5d471f4e76710a;
CRC: 00002c (ok)
DF 11: All Call Reply.
  Capability  : 5 (Level 2+3+4 (DF0,4,5,11,20,21,24,code7 - is airborne))
  ICAO Address: 471f4e
  IID         : SI-28

*200014121f6bd2;
CRC: 471f4e (ok)
DF 4: Surveillance, Altitude Reply.
  Flight Status  : Normal, Airborne
  DR             : 0
  UM             : 0
  Altitude       : 31050 feet
  ICAO Address   : 471f4e

But it’s getting more interesting while adding options. First one is –interactive which gives human readable summary with data gathered sorted by aircraft.
Looks much better:
dump1090 with --interactive

Next interesting option is –net that enables few networking features. Most impressive is webserver with map and planes on it, moving real time!
web interface of dump1090

Interesting thing is that I receive this using only stock small antenna located near window. Tuner is able to receive without any special antenna signals from planes up to 250km from me – that’s amazing.

dump1090 by MalcolmRobb

And this is not the end! There is a fork of dump1090 made by MalcolmRobb with significant improvements.
On console in interactive mode there are additional information, for example Squawk (transponder) number and heading, displayed information is also more clear:

dump1090 --interactive by fork by MalcolmRobb

Web interface is also improved. Aircrafts now looks like planes, not like arrows/triangles, browser keeps history of positions, so a trail could be draw for each flight. There is also Openstreetmap support additionally to Google Maps used earlier.
web interface of fork of dump1090 by MalcolmRobb

web interface of fork of dump1090 by MalcolmRobb

There are also other improvements. For both versions of dump1090 I use also –agressive switch. On normal PC it’s not so intensive as author warns, so it could be added without hesitation because it really improves reception and doesn’t eat cpu.

One missing thing for me – submiting data to flightradar24 site. But don’t mind me – it’s more a wish than complaining. dump1090 is really good piece of software!

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Bluetooth dongle from China :-)

I’ve been using bluetooth headpones for few months and I like this ‘wireless’ feature. Only one issue bugs me – short range. Effectively it’s sbout 2-3 meters in my home ๐Ÿ™
So, I came up with idea to buy external bluetooth dongle, preferably with external antenna to fix this problem.

I found such dongle on eBay for less than $2 (including shipping!). Yeah, real bargain. Description stated: “Operation range: 0-100m.”.
That was all what I needed:-)

After some time I received:
Bluetooth dongle
Looks good, moving antenna was a little weird, but I thought that I might broke it (cheap is cheap and easy breakable).

But I couldn’t resist do disassemble it ๐Ÿ™‚
And then surprise came outside:
Bluetooth dongle inside

External ‘antenna’ was only piece of plastic. It was so ridiculous, so I even can’t blame seller or manufacturer for a good joke. Ha ha ha ๐Ÿ™‚
So, it reminded me that there is no such thing as free lunch.
Problem unresolved.

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