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Topic: I think this guy made a mistake on ebay cheap AVR's! until he notices! (Read 1 time) previous topic - next topic

cjdelphi

ATMEGA8-16PU

http://www.alldatasheet.com/datasheet-pdf/pdf/171443/ATMEL/ATMEGA8-16PU.html


now the guy on ebay is selling them for dirt cheap! cheaper than any attiny85, i just bought 3 just incase there's a rush buy if they are indeed what they think they are...

Are they like a 328p? if so,  $1.20 free postage for a ATMEGA8-16PU would be cheap then...

if not, I just bought 3 processors for close to $3.60 i'm sure I'll put them to good use somehow :-s [edit] oh yeah here's the link to i think "mistakenly priced" atmel chips.

http://www.ebay.com.au/itm/300780166897?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

johnwasser

You can use these in an Arduino (select: "Arduino NG or older w/ ATmega8") but they have less memory than even the ATmega168.

The ATmega8 has been replaced by the ATmega8A.  You can get the ATmega8A-PU from DigiKey.com for $1.85 in quantities of 100 ($3.32 individually).
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westfw

It wasn't long ago that ATmega8 chips were selling on eBay for about $1 apiece in lots of 10 to 40, so it's not really surprising to see them again at near this price (although I don't think I ever saw $1.20 for one...)

It as 1/4 of the memory of the 328p, and two less PWMs, but it's quite a capable chip, and it will run Arduino code.

Although, brand new 328p chips selling for about $2 from major distributors like Mouser, I'm not sure it's worth the risk...

Riva

I wonder if this guy http://www.ebay.co.uk/itm/IMU-9-axis-Sensor-Module-ITG3205-ADXL345-HMC5883L-ETECOT003-/121026966436?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item1c2dc4f3a4 has made a mistake. £16 ($26) seems awfully cheap for a 9 IMU device that is all digital (no analogue) and allegedly 3-5V compatible.
Ordered one just for the hell of it.
http://forum.arduino.cc/index.php?action=unread;boards=5,67,10,11,66,12,15,17,21,22,23,24,25,29;ALL

fungus


ATMEGA8-16PU

Are they like a 328p?


Um, no. Nothing like them.

http://www.atmel.com/devices/atmega8.aspx

I think they're obsolete, too. Atmel might not even make them any more.

The best deal I ever got on AVRs was from Farnell. A few months ago they had ATtiny84s for 94 cents each. I bought a dozen ... but looking at current prices I should have bought a thousand and be selling them on eBay.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

john1993

m8 is pin compatible with m328 and code compatible with all the tiny avrs. its the original arduino chip and works for 90% of my projects which were overkill for m328. i did buy a few hundred when they were 48 cents on ebay. even now at 1/3rd the cost of m328 they are a bargain.

fungus


m8 is pin compatible with m328 and code compatible with all the tiny avrs. its the original arduino chip and works for 90% of my projects which were overkill for m328.


Yep. It's still a cool chip.

It has all the 328 hardware ... just less memory and it won't work at lower voltages.

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

bobthebanana

Not exactly related, but does anyone know the major differences between tje atmega8 and the atmega88? The only difference I've found so far (although I haven't looked much) is that the 88 has pin change interupts on every pin, wheras the m8 doesn't.

Bajdi


I wonder if this guy http://www.ebay.co.uk/itm/IMU-9-axis-Sensor-Module-ITG3205-ADXL345-HMC5883L-ETECOT003-/121026966436?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item1c2dc4f3a4 has made a mistake. £16 ($26) seems awfully cheap for a 9 IMU device that is all digital (no analogue) and allegedly 3-5V compatible.
Ordered one just for the hell of it.


I'll raise you to 10DOF for even less money :D
http://www.ebay.co.uk/itm/10DOF-L3G4200D-ADXL345-HMC5883L-BMP085-Nine-axis-module-for-arduino-/271116571530?pt=LH_DefaultDomain_0&hash=item3f1fce938a

I have 2 9DOF boards, the same as your link. They work :) I have 1 10DOF board on the way...
www.bajdi.com

westfw

Quote
does anyone know the major differences between tje atmega8 and the atmega88?

The ATmega88 is a member of the 48/88/168/328 "family", while the mega8 is an older stand-alone chip.
The UART is different.
Timer0 is different (no "compare" registers, so no PWM capability.  88 can do two PWMs with timer0)
Timer2 has only one compare channel (one PWM instead of two)

Atmel has a document:  http://www.atmel.com/Images/doc2553.pdf

pico


It has all the 328 hardware ... just less memory and it won't work at lower voltages.


The 8L variant works at down to 2.7V. Tradoff is that it is only clockable to 8MHz (but that's OK if you are running them without an external xtal, in which case you would only be doing 8MHz max anyway.) These make nice Attiny substitutes if you need more pins than on an attiny85, for example. I bought about 10 a while back for this reason.

The other limitation no-one has mentioned so far wrt to the newer 168 and 328 is that you can't use all the pins for pin change interrupts. It really just has the INT0 and INT1 external interrupts available (although there are some kludgy workarounds on some of the other pins to simulate pc ints if you aren't concerned about interrupt priority.)

If you can live with 8KB flash and 1K sram then they are certainly a viable option.

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john1993


Yep. It's still a cool chip.
It has all the 328 hardware ... just less memory and it won't work at lower voltages.


not exactly the same hardware. for example m328 has 6 pwm but m8 only 4. other than that and the difference in ram, ee, and flash pretty much the same. still a great deal and my favorite avr because i can get 6 for the price of one m328. actually cheaper for me than most of the tiny family. best of all its 100% arduino compatible.

with the help of a couple guys here i got optiboot/arduino going with 8mhz internal clock. literally no external components. cost performance ratio dont get any better.

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