Another reason I never redesigned it for AVR is that the economics are not that great. It would probably take $5 off the price but cost me a couple of weeks of time to redesign the entire thing.

This decision has had an unexpected benefit recently. A customer asked me if I could add an extra function to search-and-replace byte sequences in the data stream. Now I’m really glad to have 50 MIPS on board because a smaller CPU might not have had the grunt to do the job.

So having a way-too-powerful CPU has produced a long-term benefit to enable me to quickly sieze a market opportunity.

Next I need to set up a web page and finalize pricing so anyone can buy one.

So what is a Volume Box I hear you ask? Well, the Volume Box is a digital stereo volume control. It has no knobs or buttons, it is controlled via serial commands from a PC or home automation system. It is intended to be used as a component in an automated audiovisual setup such as conference centres, classrooms etc.

Features include:

• Attenuation from 0 to -95dB in 1dB steps
• 3 way stereo input selector
• Line level inputs and outputs
• Optional 7 watt power amplifier
• Mute function
• Preset store and recall

Here are the lessons I have learned:

1. PICs can be a mighty pain in the bum to debug, particularly the peripherals. I think I’ll use a different chip next time.

2. Always check your component footprints when designing a PCB, the Protel footprint libraries are full of errors. I’ll be patching the first run of boards due to a bad footprint.

3. Don’t try to get a product out the door around Christmas time, many manufacturing companies are closed for the holidays especially here in Australia where we combine our summer holiday and Christmas holiday into one big long holiday. Some companies do not resume business until January 18th!

Anyway, now the design is proven I have ordered some parts to begin producing these things.

My chips and other parts have already arrived so next I need to assemble it and test. I’ve still got a lot of tasks after that before it is a finished product such as designing the end panels of the box, writing the user manual and setting up a website for it.

There is no public bug-tracker for this software (yet) so if you try it out and find any more bugs, please email me at adam@siliconsparrow.com and I’ll fix them as soon as I can.

The new version is online now and ready to download at http://supertranscribe.com.

So then I spent a couple of hours making a Windows Tray App to do just that.

Then I thought maybe other people might like this too.

So I spent an additional two days setting up a website and polishing the app, making an installer and sorting out all the other little details that are needed to make it usable by non-nerds.

So here we have my new product called Ka-Ching Pal. The website is up and taking orders at http://kachingpal.com/.

Fortunately, I have found the MCP1703 from Microchip which is compatible and will do as a substitute. But now I can’t get the particular Atmel microprocessor I use, well not in small quantities anyway and I am not ready to order 1000 of them based on the sales I’m getting at the moment. So I’ve had to go up a model and get a more expensive microcontroller which is pin-compatible but I’ll have to change the firmware to make it work. This is the third time I’ve had to tweak the design of this product due to unavailable parts in the last 12 months. Such is the fun of the electronics biz!

I noticed that some web crawler had not only found the site but found my source code repository and people have been downloading the source to this app before it has even been released! I’m going to have to put up some security on that!

I’ve been working on this for a few months now on and off in my spare time. The website supertranscribe.com is up and I’ll have the beta release on the site real soon now.

Boards boards boards!

I’ve been working on a few things to improve the RS232 Bit Rate Converter. Here’s my new revision 3 circuit board.

There are some extra capacitors to smooth out a little noise I was getting in the serial data stream and I have also outsourced the machining of the end panels.

The changes are to eliminate some pain for me since I am still hand-assembling these things. I’d love to get the volume up so I could outsource the whole manufacturing process but for a niche product like this, who knows if the volume will ever become that great.

I got a new batch of boards pressed with the additional capacitors included in the layout. I have been patching them onto the revision 2 board but it is a fiddly operation, much nicer to have it baked into the design.

I have also found a more efficient power regulator which can accept an input of up to 15V. This is in response to a very common user request for the device to run off 12V. It seems a lot of people have been using them in the automotive sphere.

Now my biggest problem is lead time on parts, I still have two weeks to wait for some chips I ordered a month ago and my stock is running low.