Thursday, September 04, 2014

Homebrew 1090 ADS-B Raspberry PI Remote Monitoring Server.

This project started as an attempt to build a 1090 halfwave dipole for a RTL Dongle but turned into a complete ADS-B monitoring station using a Raspberry Pi as the 1090 ADS-B receiver and server.

I'm not getting into the full antenna construction/software setup, and assume that you have some radio/linux knowledge. This is just to show what can be done with a few bits of scrap and a cheap ARM computer.

Parts used

1 x Raspberry Pi

1 x 32Gb SD card with noobs installed. (Can be a smaller card. I just had this one spare).

1 x RTL2832u Dongle

1 x MCX to BNC cable

1 x USB rechargeable battery

1 x Empty whey protein container to be used as a water tight box for the above.

1. For the antenna I used a scrap of metal rod which was originally a part of a garden ornament that was being thown out. I used this web site to work out the lengths of each of the legs to create a half wave dipole for 1090Mhz... Highfields ARC

This is the finished article. It's not pretty, but as you will see later, the results are interesting.

I used scrap wood to make the mast and a excessive amount hot-melt glue to protect the feeder and connections from the weather.

2. I drilled a hole into the lid of the protein container and mounted the MCX to BNC lead. Again, plenty of hot-glue for rain protection.

3. To set up the the Raspberry Pi to be a ADS-B server I used this excellent write-up to install Dump1090. There's even a script to automate the setup.

Dump 1090 Install.

4. With all the bits together, time to stuff them into the container...

With the Raspberry powered up and running Dump1090, I setup Virtual Radar to decode and track 'local' aircraft.

I live between Nottingham and Derby in the UK, quite near to East Midlands Airport and could pickup quite a few aircraft with the basic antenna. But with the homebrew antenna, I can now receive planes to the north and high altitude planes as far south as London.

Next, I'll add a 12v to 5V DC-DC converter and power the rig with a small 12v motorcycle battery.

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Sunday, November 20, 2011

Chinese 50cc Scooter Transmission Rebuild and other things to do in the Cold

This my Direct Bikes DB50QT.
The belt needed replacing, so a crash course on Chinese 50cc scooters was needed.

I ordered a replacement transmission cover and belt from CMPO.
Excellent service and very quick turn-around on the order.

Write-up to follow...

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Sunday, January 23, 2011

How to repair an Hotpoint Aquarius WD420...or How to wreck a perfectly good Saturday night.

At first I tried to ignore the noise and hoped it would go away, but my hopes were dashed moments later when a second screech emanated from the kitchen. 'It's not working! The lights keep flashing!'. I knew at this point that I was not going to get any peace, so I responded with 'I'll be there in a minute dear'.

On entering the kitchen several guilt ridden minutes later, I found that indeed the washing machine was flashing like a Christmas Tree. My first thought was that the washer had some how become sentient and was trying to communicate on a rudimentary level. Fortunately for us all it had not actually gained any intelligence or was about to enslave the human race and become our mechanical overlord. It was just my overactive imagination and watching far too many sci-fi movies. Nope, it was just a simple error code.

I work with computers all the time and tried to figure out where the USB/serial/bluetooth connection was. Then I remembered it was only a washing machine. So I had to do something that is against all my ethics and read the manual (Brrrr).

The manual was written for a five year old by a salesman and had a colouring-in section at the back...'If any fault occurs on your sexy Hotpoint washer dryer, please contact your local Hotpoint Service Center'. Translation ...'Buy more. Buy more now. Buy. And be happy.
So I went and asked my friend the Internet, who gave me the list of error codes I asked for in the first place.

1: PC LOAD LETTER ...What the @**@ does that mean?
3: lights 2 and 4 pressure sw stuck on full.
Ah! There its was. The same error code I was getting. This did not help one little bit. What pressure switch?

So, it was time to do the manly thing and break out the manly tool box...

Now I know how those Egyptian guys felt when they they were dragging massive blocks of sandstone around the Giza Plateau while building the pyramids. This thing would not budge. After several minutes of cursing and claiming the doubtful parentage of the Hotpoint design engineers, the washer gave in and slid across the kitchen floor. After rescuing myself from being crushed between the Hotpoint and dishwasher and wrestling the washer across the now soaking wet floor I decided take the screwdriver to it and show it who was boss.

First I removed the lid by removing two screws at the back of the washer.

Once the two screws have been removed, the lid should slide backwards and be easily removed. It wasn't. It took a bash and a couple of those Egyptian guys to free the lid.

Also the bottom service panel had to be removed. It was only held in with two screws.

I did actually find a cover to a test port, left of the service panel. A bit like something R2D2 would connect to. Though I doubt very much my washer dryer contains any Death Star plans or controls Garbage Compactor 3263827 near Detention Block AA23.

WARNING: At this point I must point out that I had previously disconnected the power and water inlet/outlet pipes. So for the love of god at least disconnect the power. As water and electricity will turn the washer dryer into a killing machine (which takes me back to my original thought) or get a grown up to help.

My first job was to find out why the water was not draining out. So I removed the rubber gaiter connecting to the main drum, sump and overflow pipe. I carefully removed the large jubilee clip...

At this point I would recommend buying a life vest or a surf board. I have never seen so much water in my life. It was reminiscent of the title sequence of Hawaii-Five-O without the belly dancer and Steve McGarret. It was just a tsunami coming out of the back of the washer.

Hawaii Five 0 Intro YouTube

Anyway, after the mop up operations and politely asking the Red Cross people to leave, I found the source of one of the problems...

The sump inlet was so full of what looked like a Doctor Who monster (1970's Tom Baker era), the ball float was pushed against the drum outlet and stopped the water from escaping.

In the end I dug out several tons of a strange red fibre, a part of a curtain with hooks attached(?), £1.67 in loose change including a one Bulgarian Stotinka coin (WTF?), Jimmy Hoffer and a some rather talkative slime which kept reminding me about squatter's rights, and when their lawyer will be contacting me.

I have no idea...honest

 Wow! that was fun...not

Killer Washer/Dryer Part Deux
The adventure was not over yet... The dryer was was not drying, which some may consider a bit of a design flaw.

I first checked if the heater had failed, but I was getting a 47ohm reading. Then I tested the dryers thermal trip which is located on the casing of the hot air ducting on top of the machine. I found it to be open circuit. Luckily it just needed resetting. I used a paper clip to push the reset button in until it clicked

That's it...Done it... Reassemble put it back where you found it and get the hell out of the kitchen!

Conclusion: It worth working on this until 3am Sunday morning, because the missus was already looking online at a mega expensive replacement washer/dryer that also told jokes and was a Tennis Pro at the weekends.

Saturday, June 17, 2006

Excessive Belkin Router Cooling

A few months ago I purchase a nice shiny Belkin F5D72304 Router so I could play my MP3's (loudly/wirelessly) in the backyard to compete with the square waved distortion emenating from next door. Anyway...

The router had a nasty habit of not routing (This is a bad thing) after about an hour or so. The pretty flashing green LED's were now down to one occationally blinking orange LED.
'Oh' I thought...then unplugged the DC and reset the little blighter. This sorted it out for another hour, then the same thing happened again, and again, and etc etc etc.

So, I trawled the interweb for a possible solution...configuration...firmware upgrades/downgrades...
After exploring various suggested solutions (at length) about NAT's, WEPS, and DoS, I decided that life was too short and went to the pub.

The little silver box sat in the corner where I threw it with some force several days earlier. It seemed to calling me, pulling me down the long dark path of Information Technolgy.
So just before I put my lump hammer through this monster, which had previouly driven to the to the edge of insanity, I decided to give it one more chance. Off to the interweb again...

There it was 'The Answer' I hoped...
Serveral fellow Belkin customers had returned the router because of over-heating issues.
I decided, instead of returning the box, I would use this an a possible learning experience.
My plan was to slightly modify the case with futher ventilation. I needed to be subtle...

So, out with the Black and Decker Jigsaw, and my recently purchased router (no... 'rowter' for shaping and cutting large pieces of wood).

I scavenged an old CPU fan (60mm) from an old Apricot PII, and a fan cover

First I marked out the hole to be cut. Then got work on the Router with my Router. You will notice how much loving care and attention is paid to create a perfect circle...not.

Next the router board is remove from the case, so I could solder the power cable to the board.
The fan is actually 12v and the PSU is only 4.5 volts, but it drives the fan quite well. There is also plenty of current from the PSU.

Next, I had to decide how I would to attach the fan and fan cover to the case...nicely drilled holes, and use brass screws to give the job a professional finish...
No, Impact Adhesive. It quick and dirty, but the fan will never come off.

Same goes for the fan cover. It maybe a bit less subtle than a pretty finger guard, but it does give an industrial look (trying to justify my bodge).
The word 'finese' cannot be associated with this project.

There you go. It works a treat. The router has been an happy bunny for serveral days now without a lockup. I might get round to painting it one weekend.

So what have learnt here today? Well, Belkin can sabotage a good product with poor case design, and Impact Adhesive glues screwdrivers to the workbench really well.

Next time... How to cool your memory stick using a 1500HP diesel engine and 100,000 litre header tank.