Monday, May 5, 2014

Quick update - txtr Beagle, Toshiba TV firmware and queued projects

There are several projects in which people seemed interested that have a pending follow-up:

Txtr Begle alternate software

I have managed to buy another one off eBay since one month or so.
I've tried setting up the Python bluetooth suite but it's not working on Windows and there are no ready-made binaries. I do not want to force people on Windows to hunt around.
I've tried setting up a Java program to communicate via Bluetooth SPP to the Beagle. However this proved extremely unreliable and highly dependent on your Bluetooth suite and hardware adapter.

The best solution for now seems to go the txtr way: make a phone app. I will try to develop an Android app that is able to: send screenshots to the reader, send pre-rendered browser pages and perhaps pre-rendered pdf documents. It will probably take one afternoon of research and another afternoon of coding, source code will be made available upon completion.

Toshiba TV firmware

One week ago I have finally received the CD with the source code which Toshiba graciously provided. There's not much on it, certainly less than expected, I wanted to be able to be able to compile my own firmware but it only seems to include the (modified?) source code for the GPL libraries.
I will have to take a deeper look and check the uBoot modified code, that would be the key to decrypting the firmware and at least be able to compile and pack individual items.

The good news is that there is a full Webkit installation so it should be really easy to redirect the TV to a page of your choice - think router/NAS with DLNA/XBMC remote page.
The Webkit package is ironically called HbbTv.

Fail of the week projects

I have two projects that are likely candidates for the Hackaday fail section but require a good write-up if a lot of people are going to see them.

One of them is a dual power supply that I made, also described a bit in some earlier posts. It works and does the job, but barely, and I'll explain why and how it should be done. Basically a lot of DON'Ts.

The second failed (or barely working) project is a diploma project that I helped a friend with, one year ago. I was too late to the party to have useful input and instead spent days debugging hardware instead of writing the firmware. Another one full of DON'Ts.

Queued projects

The Node@Home sensor network. Quite a few projects have started implementing some of the stuff I want (like OTA firmware updates, a-la OptiBoot) but nothing hits the mark. I will also have a chance to put my newly-found Javascript skills to use.

Sony Liveview / Remote bluetooth display. This is meant to provide navigation directions when riding a bike or motorcycle. I've reached the stage where I can do a lot of the stuff with the Liveview and was considering choosing a different platform.
Unfortunately there is no API for accessing the directions from Google Maps (Android) and I've tried playing around with the Sygic one (the navigation of my choice) but their API does not seem to work. However I'm able to get directions using the accessibility API which does the purpose, if text only.
I will put the code on GitHub within a month and will also do some power/authonomy measurements on the LiveView.

Triple power supply. Basically a rehash of my current PSU implementation but with a proper PCB, current limiting and rotary encoders. At least 3 voltage outputs.

Arbitrary waveform generator. The proof-of-concept is already implemented with a Stellarpad and a 5$ ADxxxx module, but I need to add a display, case and rotary encoder to it. And perhaps an output buffer. That's 90% of the work remaining.

McHck. I've watched the community on and off and they project seems to have slowed down quite a bit. I have the parts on hand, I wanted to take a stab at designing my own PCB but I'll probably choose the smart way and order 5-10 of PCBs.
I'm just not sure I want to invest time in a project that does not seem to take off, community support is so underrated these days. I'm also worried they deliberately chose against an Arduino-like implementation and rolled their own library. They can still do it, but I think this really killed a lot of the momentum.

Boxes of things

I have already taken apart and documented >100 [dead] devices bought off eBay, with more than 30% of them repaired or repurposed. I just don't know how to group or sort them plus adding images and doing layouts via Blogger is a pain. But some of the more interesting stories will manage to get here.
I still have around 50 devices that still need checking and taking apart.

Building a cheap USB power measurement device + analysing some USB chargers

In this post I will describe a way to build a really cheap device that will allow you to measure USB power consumption and supply characteristics. It's ugly but it takes 15 minutes of your time and a broken USB hub.


Then I will take a look at various USB chargers and see how they perform, hopefully not as bad as the one depicted below: