alitalf: Skiing in the 3 Valleys, France, 2008 (Default)

It all works apart from the software!


I just need to program an Atmel ATtiny44 to measure a couple of analogue quantities and control a fast lithium battery charger, switching between off, trickle charge, and full charge, with detection of battery present, dead battery, and indication of being almost charged. There might be a use for a timeout in one section - or maybe not. Simples!

The charger even (optionally) adds negative incremental resistance to compensate for most of the resistance of the unreasonably thin battery cables. It can charge at 10A in a well controlled manner, and without getting unreasonably hot.

The software control I need is fairly simple - only a bit more complex than could have been done with something completely stateless (eg comparators and logic gates), but, in engineering of any sort, before a job can be done another must be done first, and that is indefinitely recursive. I need it finished by about mid Monday or trouble will result.

First of all I thought that the necessary software was already installed on my laptop, because I thought I had used it for something in living memory. No, the laptop failed and had everything I needed at the time re-installed, so I had to find out what things I need - which turns out to be AVR Studio and Winavr. I have an AVRISP 2 to program with which should be fine.

I have just reached the point of having upgraded its firmware to play nicely with the latest AVR Studio.


I do remember that there need to be some include files to make life easy, and I also remember needing to interpolate and extend the instructions in order to make that aspect of it work.

If When eventually I reach the stage that the header files are where the program expects to find them, so that the port addresses are defined and it is possible to address them by name, there will be some chance I can do the rest of it in a plausible number of hours. After all, the code needed should be simple enough that even someone out of practice like me, should be able to make it work. There is plenty of code memory, so it doesn't need to be optimised to the last instruction.

This is getting too close for comfort - I thought that both the computer and my memory were better prepared for this task. Maybe the missing bits will make sense tomorrow. As soon as I can even make the processor as much as toggle an output, I should be on the home straight.

alitalf: Skiing in the 3 Valleys, France, 2008 (pic#91180)
I spent most of my day working as a counsultant for a company with offices in Milton Keynes, at their offices and at one of their suppliers. I discovered a number of problems on the electronics they were being supplied with, much of it at the pre-production sample stage. Bullet dodged, from their point of view.

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alitalf: Skiing in the 3 Valleys, France, 2008 (cat-1)
On Thursday morning I received an appointment letter for the x-ray I need for my right shoulder. Once the x-ray is done, next Thursday morning, I should be offered a physiotherapy appointment. I still wish it was happening more quickly, because the available movement without severe pain is gradually becoming more restricted, but at least there is some progress. Now I can angle my arm maybe 20° out from my side, more than that forwards (and not backwards at all) before it is too painful to move further.

The pain was worse at the beginning lf last week, though, because, for a while, there was no pain free position, and it was rarely less than excruciating.

In other news, I have a short term, but demanding, power electronics project to work on. I get to design the power electronics for a high power LED lighting system, that is designed to save considerable energy compared with the system it is to replace. Getting sample magnetic components quickly enough to assemble a prototype in time to meet the deadline is likely to be one of the more difficult aspects.
alitalf: Skiing in the 3 Valleys, France, 2008 (Default)
Late Monday morning I had a call from Lamorna, whose friend had a computer problem. I had fixed said friend's internet connection some time back, just after her husband, who did the tech stuff, had died of a hospital infection a long time after going in for something relatively routine.

This time I managed to find out that the virus report from the scanner was a false positive, and replace the antivirus program with one I trust more, and which incidentally doesn't slow the computer down so much.

Now I have partly caught up with my work, and just emailed to my customer the printed circuit layout for an 868MHz wireless transceiver for remote control. Now I have to return to the question of the transformers which get hot, for the same customer. Rats, I also have a web page to design for another customer and some work on a high voltage circuit for a third. If nothing takes longer than it should, I ought to be almost up to schedule, even with the stuff I got behind on last week, by Wednesday mid afternoon, in time for some as yet unscheduled product evaluation work for yet another client that has an office in Milton Keynes.

Being a freelance, there is too much to do or too little. Well, I've got to pay for the holiday in Japan, so right now too much is better...


alitalf: Skiing in the 3 Valleys, France, 2008 (Default)

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