Replacing the controller

[mb345]

Hello everybody.

I burned the controller on my TV-B-Gone kit because I used a power supply instead of batteries but didn't limit the current.
(So everybody, be warned to carefully control the maximum current if you use a power supply!)
This was some time ago, so it's a V1.1 kit.

Now I thought I'd dig it out again and give it a try and replace the ATTINY which I'll certainly have to reprogram but that should be doable.
But the only source that I found where I can get one in Germany with decent shipping costs is from Reichelt (http://www.reichelt.de).
Now they don't have a 85V-10PU, only a 85-20PU, 45V-10PU or 85V-10SU (and many more types which are not relevant).

From reading the data sheet, I understand that the 45 series has only 4k of Flash. Would that still be enough for the TV-B-Gone 1.1 program code?
The 85-20PU has a voltage range of 2.7 - 5.5 V which is most probably not good with 2 AA batteries (and I don't want to use 3).

Is it maybe the best solution to get the 85V-10SU? It should be possible to mount it although it's SMD.
What do you guys think?
Any help will be appreciated.

Best regards,
Markus

[adafruit]

you will need an 85 chip
85v is best, others may work but not guaranteed
we also have replacement chips in the shop here

[Agent24]

You could use the SMD version with an adapter board such as these:

http://cgi.ebay.com/2sets-SOIC-DIP8-PCB ... 0414230426

[mb345]

Thanks for the quick replies.

So I'll get a 85V-10SU from Reichelt.

Thanks for the hint that controllers are available from the shop (I was asn't aware of that), but shipping cost to Germany would be 7.80 $ and I think that's a slow shipping variant as there is another one for about 20 $...

Also thanks for the hint to the adapter, maybe I can find that here as well. Or I'll make something similar myself, I think I have some SMD experimental board lying around where I can cut a piece off.

One more question: Can use a 1.2 software with my 1.1 hardware?

So long,
Markus

[Agent24]

Not directly, as the hardware is different - you would need to modify the firmware first, what exactly you would need to change I do not know, but something to do with the LED driving pins (v1.2 only uses 1 pin vs 2 pins in v1.1) and then there's the EU\US code selection resistor which doesn't exist in v1.1

Possible, I am sure, but I have never written any AVR code.

[richms]

I have used an 8pin DIP socket in the past to convert a surface mount chip to DIP - hot glued it in the middle and then soldered wires between the pins and the pins of the socket. tiny, messy, but will get you working hopefully.

[vxbinaca]

What about the 85-20PU? Skimming the specs the only difference I can see is this runs at 20mhz instead of 10. Doesn't the crystal slow it to 8 no matter what? If the pinouts and requirements are the same, it should work as a drop-in replacement.

Thing is, eBay has these but not the 10PU's and Mouser's prices are higher plus the shipping. I only wanted like 10 or so units.

[Agent24]

What about the 85-20PU? Skimming the specs the only difference I can see is this runs at 20mhz instead of 10. Doesn't the crystal slow it to 8 no matter what? If the pinouts and requirements are the same, it should work as a drop-in replacement.

As far as the frequency is concerned you are correct. However there is another difference, that of the operating voltage range.

It's 1.8 - 5.5V for ATtiny25V/45V/85V but only 2.7 - 5.5V for ATtiny25/45/85

The TV-B-Gone needs to use the V version which can handle the lower voltage, as the current draw on the circuit is quite high - the standard version can reset during operation because the voltage can fall below 2.7v.

Of course if you have a high capacity power supply\battery then you would probably be fine using the standard part.

[vxbinaca]

Agent24, What about if I use a 3/4 AA pack with the 20PU? Would that work?

Also, the ATtiny85v-10SU is more expensive than the thorough-hole version. Weird. I just ordered 25 PU's recently and flashed them all in one sitting and put them back in the tube. Mouser doesn't really offer good deals on these chips.

I wonder if there is a BGA version of any of these chips.

[Agent24]

Agent24, What about if I use a 3/4 AA pack with the 20PU? Would that work?

I wonder if there is a BGA version of any of these chips.

Not sure what you mean by 3/4 AA...

I expect there is no point in BGA for an 8-pin device... SOIC is probably small enough for most people and I doubt they want to spend extra money to make a BGA IC that tiny. (I may be wrong)