So, now I hopefully(!) have my cable which will give me access to the UART RX of the CC128 energy monitor. Time to try it out and begin processing some data with it!
Firstly, I go to the XMOS website and get the UART code and play around with it to create the UART code I want (RX only at the moment), compile it and give it a run.
But it’s never that simple! All I get are null characters. Odd I think – so I recheck the wiring, recheck the code. All seems to be ok.
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The “Thats the warranty gone…” aka as a ‘teardown’ post!
With the UART TX not working properly I was forced to open it up… so here is a bit of analysis and some photos of what is inside for the curious!
My energy monitor arrived today! It’s working well – I was slightly worried about how good the reception would be for the transmitter, but I am pleasantly surprised that even with the receiver 3 floors above the transmitter it seems to register a good signal.
But that’s boring – time to start hacking!
So, first thing I need is the interface cable. The back of the unit has a handy RJ45 connector that has serial in it (see my initial energy monitoring post). This needs connecting to my XC-3 kit so that I can begin to get the data out of it. So time to get the soldering iron out!
Was at a friends today and he showed me an energy monitor that he had bought and was using to monitor his electricity supply. I was like “hmm… this could be something fun to attach to an XCore and get some graphs out of”.
My thought is to use my XC-3 (or maybe get an XC-2) to connect to an energy monitor receiver – or hack/make a receiver and then push the data somewhere useful via Ethernet. In fact I could combine it with my network monitor, ditch the screen and have it push the all the different types of data out into some nice pretty graphs. Anyway, enough brain dump – onto the hardware!
Over the last few weeks I have come across some nice XMOS based projects:
1) Laser Cutter
Not massively complex in terms of software – but a pretty cool outcome. UART in – granite engravings out! Nice… Maybe an ethernet interface with a web client to upload images into it could come next… laser engraver source code here
The main purpose of the project it’s to create an autonomus vehicle to explore lakes and reefs. Aquatic Bot Explorer (ABE) its based on a ROV (Remotely Operated underwater Vehicles ) and AUV (Autonomus Underwater Vehicles ) class robots.
This bot it’s powered by an XK-1 processor by XMOS, several boards for sensing: pressure, temperature, depth, etc. Motor control, demux, ADC, etc. are developed.
Looks pretty cool… can’t wait to see what it turns up from the depths!
The XMOS XS-1 architecture is a multi-threaded architecture. As opposed to normal systems it has a single processor core that can run 8 hardware threads, in real-time with no operating system overhead. But what happens if you run out of threads… 2 answers: either (1) add more cores or (2) virtualize.
So I thought I would do option (2) as option (1) is too easy in the XMOS architecture and its not very efficient if I want to run 1MIPs processes on a thread that has 50MIPs available. The code for this is freely available from the virtual threads sourceforge page.
More information after the break…
