What do I need for programming ATtiny25?

[cajampa]

@RMM

Or you can program it with a breakout board before reflowing it onto the board.

From the Oshpark Projects Thread

@RMM

This board should be useful for testing and programming the “tiny” attiny13a (MMU). It is labeled with USBAsp pins for easy hookup (I always mix up at least one pin every time I wire up a new programming clip! )

Ok, so it is possible before the reflow then.

Edit
This is very interesting RMM, that would make the hookup much easier
Have you done any projects with the -MMU size?

EDIT2
I don’t have the skill to do this yet, but i imagine a tiny driver with very small smd components, a tiny FET and the attiny13a-mmu for easier fit (and in some cases makes it possible) in smaller lights

[wight]

Also I’m sure that there are many plastic housings used for this sort of thing. Things of this sort:
http://www.programming-adapter.com/QFN-prog-adapt.htm
http://www.aliexpress.com/store/product/QFN-0808-01-Adapter-QFN8-D8-WSON8-DIP8-Programming-Adapter-DFN5x6A-8-Test-Socket/818356_751535011.html
http://www.weilei.com/QFN11E.htm

[Microa]

Usually we make a pogo pin programming adapter for the specific board, so that we can update the code later.

[vex_zg]

@Mike C

@vex_zg

While we’re at it - what is the reason not to go for attiny45 or 85? they have 4k/8k, I think 25’s 2k could become a limitation easily.

They can be used on the same footprint as the ATtiny13a if you carefully bend the legs back under it and use hot air to solder it.

Can do that!
Which clip can be used to reprogram? I have the one for the 150mil ATtiny13A, I presume it will not clip onto the 208mil ATtiy45/85

edit:
this is the cheapest 85 that I could find, considering the shipping and the per unit costs, unit price comes out as cca $1.3 with free shipping.

http://www.ebay.com/itm/10PCS-ATMEL-SOP-8-ATTINY85-20SU-Tiny85-20SU-CHIP-IC-/371220134717?pt=LH_DefaultDomain_0&hash=item566e71bb3d

Mikrotik sells them for $1.5per pc + $8.5 shipping (Sweden)

Datasheet for ATtiny13

1626866.pdf

Datasheet for ATTiny25/ATtiny45/Attiny85

1698186.pdf

Question 1: Is this the 208mil package mentioned earlier as the smallest package for the 85? yes it is,
Question 2: Will the SOIC clip used for Attiny13A clip onto this one? There are some differences between 8S1 and 8S2 packages, but I can’t be sure if the Regular pomona SOIC8 clip can tolerate it or not.

Question 3: Which version of the 85 to order: 10Mhz:1.8-5.5V or 20MHz: 2.5-5.5V ?

[wight]

• That’s the smallest SOIC package, other packages are flat-no-leads packages.
• The SOIC clip will fit both 150mil and 208mil.
• I’d get the low voltage version. It’s not a big deal though. Check the voltage/freq list/table at the top of the datasheet. Subtract 0.2v from the lowest battery voltage we plan to run the MCU from (2.8v?). Make sure the MCU can do 4.8Mhz at that low voltage.

[vex_zg]

@wight

* That’s the smallest SOIC package, other packages are flat-no-leads packages.

• The SOIC clip will fit both 150mil and 208mil.
• I’d get the low voltage version. It’s not a big deal though. Check the voltage/freq list/table at the top of the datasheet. Subtract 0.2v from the lowest battery voltage we plan to run the MCU from (2.8v?). Make sure the MCU can do 4.8Mhz at that low voltage.

the low voltage version is cca 60% more expensive. Can I go with normal version?

[vex_zg]

Found another source for Swedes, there’s a shop in Solna/Stockholm:

https://www.elfa.se/elfa3~zz_en/elfa/init.do?item=73-219-27&toc=20966

I am still unclear should I get the low voltage version or regular, the low voltage is quite a bit more expensive

[Mike_C]

@vex_zg

Found another source for Swedes, there’s a shop in Solna/Stockholm:

https://www.elfa.se/elfa3~zz_en/elfa/init.do?item=73-219-27&toc=20966

I am still unclear should I get the low voltage version or regular, the low voltage is quite a bit more expensive

I’m actually going there tomorrow after work. Want me to pick something up for you?

[Mike_C]

Oops, I’m actually not going tomorrow. I forgot to check in store stock, they don’t have what I want in the actual shop.

[Mike_C]

@vex_zg

Can do that!
Which clip can be used to reprogram? I have the one for the 150mil ATtiny13A, I presume it will not clip onto the 208mil ATtiy45/85

Forgot to answer this one… The clip I use for the 13A fits on to my 85s.

[RMM]

@vex_zg

@wight

• That’s the smallest SOIC package, other packages are flat-no-leads packages. * The SOIC clip will fit both 150mil and 208mil. * I’d get the low voltage version. It’s not a big deal though. Check the voltage/freq list/table at the top of the datasheet. Subtract 0.2v from the lowest battery voltage we plan to run the MCU from (2.8v?). Make sure the MCU can do 4.8Mhz at that low voltage.

the low voltage version is cca 60% more expensive. Can I go with normal version?

Yes, but it will shut off at around 2.8v. If you don't care about that, then you can use the non-V version.

[vex_zg]

@RMM

@vex_zg

@wight

* That’s the smallest SOIC package, other packages are flat-no-leads packages. * The SOIC clip will fit both 150mil and 208mil. * I’d get the low voltage version. It’s not a big deal though. Check the voltage/freq list/table at the top of the datasheet. Subtract 0.2v from the lowest battery voltage we plan to run the MCU from (2.8v?). Make sure the MCU can do 4.8Mhz at that low voltage.

the low voltage version is cca 60% more expensive. Can I go with normal version?

Yes, but it will shut off at around 2.8v. If you don’t care about that, then you can use the non-V version.

I want it to be able to run it down to 2.5V

however I read that the attiny itself will not shutdown automatically on low voltage, but rather you yourself should shut it down using brownout detection to prevent issues, such as eeprom corruption.

Since Attiny85 is designed to run at 10MHz at 2.7V, I’m hoping that it can tolerate 4.8MHz@2.5V

So, of course I ordered two attiny85, normal version, to settle this for the future.

[wight]

@vex_zg

So, of course I ordered two attiny85, normal version, to settle this for the future.

If this is your way of thinking I am unable to help you.

The datasheet is very clear.

[RMM]

The attiny25 shuts off at around 2.8V-2.9V (remember, there is a voltage drop from the diode), at least in my testing it does at 8 MHz. At 4MHz it should go a little lower.

You are dreaming if you think it will go down to 2.5V, especially with a diode in place.

[vex_zg]

At those low voltages , below 3.0V, LED would be running in moon mode, with a few mA.

The specs draw this diagram of “safe operating area”

Atmel-2586-AVR-8-bit-Microcontroller-ATtiny25-ATtiny45-ATtiny85_Datasheet.pdf

page 163

So I was thinking that there should be a margin, I’m only looking at 10% lesser voltage at half of the frequency, in my CPU overclocking career that should be achievable.

However, in a few weeks I’ll know for sure, I just have to, so if there’s a chance it can work, I don’t have to order 85V in the future, even if it’s a long shot.

I’ve read about a brownout detection fuse, perhaps it can be disabled to disable automatic shutdown (if one happens), and then I would anyway manually go to “sleep” at 2.5V.

edit: c/p from the spec:
“VBOT may be below nominal minimum operating voltage for some devices. For devices where this is the case, the
device is tested down to VCC = VBOT during the production test. This guarantees that a Brown-out Reset will occur
before VCC drops to a voltage where correct operation of the microcontroller is no longer guaranteed. ”

I apologise if I insulted anybody with my impulse buy But 85V is basically double the price.

Is the diode there only for reverse polarity protection?

[RMM]

@vex_zg

Is the diode there only for reverse polarity protection?

Yes.

[vex_zg]

@RMM

@vex_zg

Is the diode there only for reverse polarity protection?

Yes.

thanks. I’ll let you know the results, so you can tell me “we told you so”.

[Mike_C]

@cajampa

I called farnell and we swedes can’t buy as private individual directly from them, but they recommended i order through https://www.microkit.se instead, i called them it looks to work out great they charge 69kr in shipping for an order of up to 500kr.

Just placed an order with them and thought I’d add the info here that if you exceed 500kr (inc taxes) shipping goes up to 129kr (inc taxes).

[vex_zg]

@Mike C

@cajampa

I called farnell and we swedes can’t buy as private individual directly from them, but they recommended i order through https://www.microkit.se instead, i called them it looks to work out great they charge 69kr in shipping for an order of up to 500kr.

Just placed an order with them and thought I’d add the info here that if you exceed 500kr (inc taxes) shipping goes up to 129kr (inc taxes).

Only in Sweden
Elsewhere I’d expect them to give free shipping

[Mike_C]

@vex_zg

Elsewhere I’d expect them to give free shipping

Yeah, seems that when the package is worth more they want to send it traceable and signed for, which costs them more. I called them up to see if they had a limit and the guy on the phone started to explain to me how small the margins are in this business, and that they basically are only money shifters.