Saturday, September 13, 2014

Designing the Xadow - SD module

I am always looking for Arduino modules with small form factors, the first Arduino I ever got was not the classic chunky board , it was a Mini Arduino Pro. I proceeded to attach that to a quadcopter with some success in the era before pre-built ardupilots.

Lately I have been playing with the Seeed Xadow form factor modules. They are designed for a smart watch projects. My aim is to build a camera hot-shoe capable of injecting GPS into the exif as well as logging the orientation of the camera in Omega-Phi-Kappa co-ordinates. Something similar to the Solmeta unit or the much more affordable Navspark SUP800F, but with accelerometer-gyro-magnetometer combined to work better on more dynamic platforms i.e. a Helicopter circling a point and experiencing centrifugal force which can throw the accelerometer based gravity calculations off.

Xadow module chain including Xadow SD
The Xadow system has pre-built modules for most things including a 9-DoF IMU with the MPU-9150 on-board, low power OLED module for display and a GPS. These components can be used to build a complete AHRS + GPS system with one thing missing - large data storage. The pre-existing Xadow - Storage module offer only 64K of storage in EEPROM, an opportunity to make something new.


SD card shields are easily available in the standard arduino ecosystem, but none exists for the FFC cable based Xadow form factor. So I took an SD shield design and shrunk it down to the Xadow size. It is now available on the Seeed Wiki as Xadow - SD component. The next revision has bread-boardable breakout pins on the side for use as an SD card reader with any other system. So the Xadow watch can now have 32GB of storage. With the Cortex-M0 based Xadow main board and colour display anyone can now make a poor-mans version of the iWatch.

If you are interested in the Xadow system, grab the SD card module design here and give it a try. I also have some blank PCB's I can give away to anyone who wants to practive some SMD soldering.


Monday, July 21, 2014

Adding SBS Adelaide Manually to TVHeadend

Recently I ordered a new USB Tv-tuner via Aliexpress. As expected it arrived without extra packaging and drivers, but complete with a tiny antenna. After some googing with the USB VID:PID ( Bus 001 Device 016: ID 15f4:0131 HanfTek ) I found some notes about support in Kernel 3.13.
Astrometa Tuner - Also supported by Kernel 3.13

So I upgraded an Eeepc I had sitting around to this kernel and the TV-Tuner card showed up. Next phase of the adventure was to share this new found tuner to the rest of the house via TV-Headend.

[12546.596154] usb 1-1: new high-speed USB device number 16 using ehci-pci
[12546.738398] usb 1-1: New USB device found, idVendor=15f4, idProduct=0131
[12546.738414] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[12546.738425] usb 1-1: Product: dvbt2
[12546.738435] usb 1-1: Manufacturer: astrometadvbt2
[12546.744405] usb 1-1: dvb_usb_v2: found a 'Astrometa DVB-T2' in warm state
[12546.812321] usb 1-1: dvb_usb_v2: will pass the complete MPEG2 transport stream to the software demuxer
[12546.812379] DVB: registering new adapter (Astrometa DVB-T2)
[12546.816555] usb 1-1: DVB: registering adapter 0 frontend 0 (Realtek RTL2832 (DVB-T))...
[12546.826784] r820t 6-003a: creating new instance
[12546.838662] r820t 6-003a: Rafael Micro r820t successfully identified
[12546.845398] Registered IR keymap rc-empty
[12546.845785] input: Astrometa DVB-T2 as /devices/pci0000:00/0000:00:1d.7/usb1/1-1/rc/rc11/input33
[12546.846154] rc11: Astrometa DVB-T2 as /devices/pci0000:00/0000:00:1d.7/usb1/1-1/rc/rc11
[12546.846621] input: MCE IR Keyboard/Mouse (dvb_usb_rtl28xxu) as /devices/virtual/input/input34
[12546.847310] rc rc11: lirc_dev: driver ir-lirc-codec (dvb_usb_rtl28xxu) registered at minor = 0
[12546.847334] usb 1-1: dvb_usb_v2: schedule remote query interval to 400 msecs
[12546.859647] usb 1-1: dvb_usb_v2: 'Astrometa DVB-T2' successfully initialized and connected


Getting TV-Head end installed via the debian repository was a breeze, just add it to apt-sources after importing the signature. Adding channels is fairly easy as well, go to the TV Adapters page, select the adapter and Add DVB Network by location, in my case this was au_Adelaide. All channels added successfully except SBS Adelaide, which seems to have changed frequencies recently. So I dug up the new frequency - 184.5MHz and decided to add the Mux by hand.

Basic Tv-Tuner page for TV-Headend

Just the centre frequency and bandwidth are required, everything else can be left on "Auto".
Adding SBS Adelaide MUX by hand
Adelaide DVB-T channel list (including retuned SBS)


After the MUX shows up in the list, press play and this will scan the MUX and auto-add channels. These channels however will be nameless and require "Map DVB services to channels" in the main page to be named properly. Afterwards the full channel list including SBS Adelaide looks something like below. From there it is just a matter of hooking it up to VLC or XBMC. Happy Tour-de-France watching and recording ahead.
SBS Via TV-Headend into VLC

Thursday, May 15, 2014

All over Cambodia in 3 weeks - Siem Reap

Last December and January I cashed in my annual leave and some more to go travelling in Cambodia for almost a month.

The fantastic ancient temples of Siem Reap cannot be quite enjoyed in a day, but in one hectic day starting in the dark at 5am we came quite close. Pity the $30 extracted from millions of tourists every year ends up in the hands of a Vietnamese contractor.Baphuon sleeping BuddhaWe managed to visit the impressive Angkor Wat before a rather lack luster sunrise due to the clouds. Then off for a jaunt on the tuktuk through the myriad temples of Angkor Thom. Finally we managed to convince the reluctant driver to make the long trip to Bantey Srei (The Women's Temple) and admired its beautiful carvings as the sun set. Apsara Detail
The night in Siem Reap is an entirely separate experience all by itself. Where the temples show the grandeur of ancient Cambodia, the Night Markets and Pub Streets of Siem Reap reflect the vital resurgence modern Cambodia is exeriencing from the decades of bloody civil war. Granted most of the industry is rather grey and exploitative in nature, it is still good to see haggling in the market and mass production of temple based artwork from a few originals made by actual masters.


All told I would have loved to stay in Siem Reap for a month to catch the perfect sunrise over Angkor Wat and the perfect sunset over Bayon, and indulge in the debauchery in pub street every night.

Wednesday, April 9, 2014

Building a Many GPU LTC rig

 I acquired most of my BTC gear through eBay (only a couple of Hashbusters directly from Ukraine and a Single while BFL had them on sale). They cost a premium there, but it was fun playing around with the variety of gear. I have resold most of the things by now and received a note about strange power usage from Simply Energy. I wanted to save myself some trouble and get an LTC rig off eBay, but the prices seem not worthwhile. The description of the rig is generic, almost like a pre-order, the seller is offering to build it for you assuming you cannot handle motherboards and pci-riser cards.

So I decided to have a go and thanks to the numerous guides and forum posts, setting up a rig with 2 GigaByte AMD 270x cards was a breeze (opencl calls them pitcairn). The 270x's are power hungry, taking about 200W each, you will need at least a 600W PSU with 2 cards to keep up. Get a modular PSU and will come in really handy in keeping all the cables neat and tidy and switching to powered PCI-e riser cards. I was planning to build a 4+ cards unit, so I got the Corsair RM1000 PSU.

Next was the choice of a Motherboard, it ended up getting the MSI Z87-43 with 2 x16 slots and 2 x1 slots usable with risers. In retrospect the Z87-45 would have been a better choice since it can handle more PCI cards or the made for BTC ASRock H81 pro BTC. After that there are behemoths such as the Trenton PCI host board with 18slots.

Getting the AMD Catalyst Drivers installed on Linux is a major pain. Finding the right patch requires some searching, but in the end it works quite nicely. After getting 1 machine working I imaged the SD card using win32diskimager and set up other motherboards I had lying around to run the same config. Just as I got going I realized that with the advent of ASIC's the supposedly ASIC resistant scrypt mining is now beyond GPU's time to look into vertcoin or dedicate these to Folding@Home.

Meanwhile if you are still playing with Scrypt based altcoins check out wafflepool and my Android widget to keep tabs on it.

Friday, December 13, 2013

A few days in Samoa - Reefs, Thieves and Blue waters

We went to Samoa (the Western one not the American one) for a few days to experience sun, surf and the typical tropical paradise things. However paradises are very fragile, snorkeling is difficult since reefs are dying after a tropical cyclone, which flattened some of the best resorts.
Beach Fales
Beach Fales along the Eastern shores of Upolu

Churches are everywhere, our resort was right next to a very large Methodist compound. The biggest building in Apia is probably the L.D.S. church with a shiny top. In spite of all the religious zeal the commandments are not obeyed, we had been warned about theft at the resort by TripAdvisor and it did happen. Some money disappears from our resort room, the police got called in to take statements from the staff. Only fair given Australian Federal Police is shoring up the policing in Samoa.
To-Suo Swimming hole
The To-Suo water hole at low tide

We drove around for a couple of days, getting througly lost and finding some wonderful places. Samoans only started driving on the left side of the road recently and about 50% of the cars are still left-hand drive, sharing the road with them is dangerous at best. I went off road for a bit and managed to get stuck in mud in pouring rain. A local thankfully came by and helped us extricate the car with some well placed planks.

Eventually we got to To-suo after repeated searching at opposite ends of Upolu. I had a stroll through the Livingstone museum and took photos of falls at sunset. Ate greasy food at the local market, stared at huge taros and rode the local bus (one of which was swept of a ford by a river the day after we left). I was a fun holiday overall.
Sopoaga Falls
Falls near Falefa

Saturday, November 30, 2013

Reflashing BFL Jalapeno with UDOO

I funded the UDOO kickstarter a while back and received it a few weeks ago. The bot I was planning to put it on already has a controller, so the UDOO now lives a sad life as a BTC mining hub.
JTAG Port Pinout - Jalapeno has silk screen for 1 and 9

Testing the GPIOs on the UDOO manually
I have a couple of Jalapenos which I overpaid for on eBay and are all sold out due to Black Friday, but the prices are going up on BTC and I figured I could make them slightly more desirable for resale by performing a firmware upgrade. There are guides for performing the upgrade using the AVR-Dragon JTAG and the Raspberry Pi. Since the UDOO claims to be 4-Pi's in one it should be more than capable of running urJTAG using the GPIO cable and reflashing. The compilation took a couple of attempts due to the lack of back-up battery on the UDOO, every time I rebooted the time had an epoch reset and make got stuck in an eternal loop, eventually it settled down. You can also apt-get install urjtag, but that version does not have the GPIO cable.
UDOO GPIO pins used

On the UDOO we have a very large selection of GPIO's to choose from, for convenience I selected 4-near the edge - 88,56,105,89 and 144 for reset. Then used the Pandaboard GPIO toggling guide to get into the /sys/class/gpio file structure and quickly test these pins with an LED. The UDOO GPIO's are at 3.3v so it is safe to use them with the Jalapeno. I also colour coded the cables for future reference. Here is the table of the colours and pins on both the UDOO and the Jalapeno. The reset pin can be toggled using the LED testing method above to reset the board if you get stuck, simply output "low" then "high" to GPIO 144.
Cabling between Jalapeno and UDOO
Function Colour Jalapeno  GPIO
RESET Grey 6 144
TCK Yellow 1 89
TDO Purple 3 104
TMS Orange 5 56
TDI Blue 9 88
GND Black 2 GND
Once everything is connected fire up the Jalapeno and reflash it using the JTAG command chain below. I would really like to gather some statistics on the results of the detect command to see which CPU people have.
urJTAG reflashing of Jalapeno AVR
That's it, a great use for the many UDOO GPIO's go crazy and hook up 10 Jalapenos at once and run a reflashing service or send it to me for a reflash. If you found this useful BTC donations are welcome - 1JGoD1muFP5RiGPUWF12ncYz2WreYk35Rh .

Saturday, November 23, 2013

All forms of LTC mining - CPU and GPU (OpenCL/CUDA)

CPU mining is definitely deprecated. You never get the bang for power, unless you have machines with 32 cores and free power. Well at least for BTC. For LTC cpu mining (very slowly) is still feasible. Quite good if you have one of those 32 core - 128GB RAM beasts lying idle, or you are Amazon or Google. Just fire up pooler's minerd and take up a bunch of CPU's. A little bit of math shows EC2 CPU power will not be worth the investment, but with LTC prices heading north of $10 theres is no telling what people will try - including writing minerd into viruses. Amazon might stop EC2 service and start CPU/GPU miners itself.

CGMiner 3.7.2 with scrypt support can also get a fairly good rate on AMD Radeon cards with better OpenCL support. The ROI on these cards is definitely better than any of the miners in hand. Meanwhile people are pay AUD700 for 5GH BFL Jalapenos on ebay and joining the BTC bandwagon. Fun times ahead.

I am enjoying myself trading LTC/BTC and getting cheap thrills on penny stocks. Much better than when my horse (Verema) came last at the Melbourne cup, stumbled fell and had to be put down. I still won for last place. Even if like the horse, this vaporware currencies stumble fall and have to be put down they will leave behind legends and fiat currency millionaires.