Cab's Hacking Blog

Link: http://www.mightyohm.com/wifiradio

The project has taken a bit longer to do than I thought. Basically it’s because I’ve got other things to be getting on with. Thanks to the nippers being on holiday and not in the house, this has meant that I can concentrate on this.

Bear in mind, it’s been a long time since I’ve done any real electronics, but so far, this project has been very easy to do.

Some issues that I faced are:

1. USB sound dongle. Check out the mightyohm.com website to get an idea as to which ones are compatible with the Asus router. The Speedlink SL-8850-SBK does the job very well.
2. Blowing the firmware onto the ATMega 168 chip. On my 64 bit linux box (running the Fedora 15), I had a very tough job in compiling the avrdude software. Basically, it just wouldn’t work. I went the expensive route and ended up buying a s/h Apple MacBook (which I can play with later on for other things, such as Apple app development). I had no issues at all with the MacBook.
3. Not being able to tune the radio using the pot. This was down to the fact that I’d connected a wire to the wrong pin of the ATMega. D’Oh.

So far, I’m at end of step 9 on the mightyohm website and I’ve transferred the circuit to a PCB. After a few hiccups (such as not soldering things properly) the skeleton of the wifiradio works.

Next step is to purchase a cheap set of speakers. I’ve ordered these:

http://www.trust.com/products/product.aspx?artnr=15406

Okay, they may not be the best, but they’ll do the job for me.

I’ve also changed the standard attenna for a more efficient (15dB IIRC) one.
Things to do are:

1. Build a case. Now I’m not a designer and my carpentry skills are not superb, so this will be quite tough.
2. Strip out the speakers and amp ciruit when it arrives.
3. Remove the USB connector from the router, so it can be moved to a more convenient location. I’ll need to be careful on this, so I don’t knacker the Asus PCB.
4. Build a PSU? Or maybe I’ll have an old PC PSU in the garage. This’ll give me 5V and 12V in the event that the speakers are on a 230V in - 12 V out power supply. Need to wait on this.
5. Otherwise, I’ll need to check out another power supply that’ll give me a supply to the LCD PCB, the Asus router and the speakers.

I’ll also need to get a couple more pots for the LCD display and the tuner. I’m not happy with the ones I have as I don’t think they’ll be suitable for the case.

I’ll also have a look at ebay or some of the car boot sales, to see if there are any suitable cases knocking about. This’ll save me some work.

From the cost side of things, these have spiralled (I’m not too fussed) because I’ve been getting back into the whole electrikery scene again. I’m sure that if I did this all again, I could be well within budget.

Current costs involved:
1. USBTiny firmware blower for the ATMega
2. MacBook (Urk)
3. Assorted electronic components
4. Speakers
5. Case (or parts for a case)
6. Asus router
7. Improved antenna
8. USB dongle (x2 as I actually purchased one that didn’t work as I didn’t check out the website previously)
9. New soldering iron (little Urk)
10. Odds ‘n sods such as PCB holder, breadboard, cables for breadboard, etc, etc, etc. Bearing in mind that this was a return leap into electronics and I had very little (read: none) of this equipment.

Some areas that I can improve on:

1. Soldering. I’ve been too excited to get this done quickly and should be much more patient.
2. Cables and connectors. I’ve buggered up a few because of the same reason above.
3. Misc. I’m sure there are a lot more areas that I can improve on. The main thing is that I need to be patient!!

Further updates later on. But it’s been great fun so far!