Direct from China
It is notorious that modules/chips sold on Chinese marketplaces can be fake ones. Most of the times, it's not much of an issue for non-industrial applications. As long as the components behave properly, it is almost impossible to check their quality/authenticity.
As I wanted to explore the programming of ATtiny85, I ordered a couple of them on AliExpress. Then time flew and a long time after the "return/complain" window was closed, I gave them a try.
Nothing... Impossible to do anything with them. I double-checked the wiring, but I always ended-up with the famous:
"Device signature = 0xffffff".
Reputable French shop on Ebay
Certainly puzzled, I ordered another pair, this time from a shop I previously used succesfully on ebay. Having received them the next day (one big advantage of buying local!), I tested them and they worked straightaway.
Fuses and quartz
One of the main reasons of a bad signature when programming seems that there is a setting of internal fuses to use external quartz at a specific frequency. I tried my entire stock of quartz (6 "standards" values)... without success.
High voltage programming
The next step was to try "High" Voltage (meaning more that 5 volts, not mains BTW), using these solutions:
- High Voltage programming/Unbricking for Attiny
- Recover Bricked ATtiny Using Arduino as high voltage programmer
The signature reported was:
Signature = 0x9004
which indicate an ATtiny11! For a ATtiny85, it should be 0x930B...
The fuses were (always):
0x6C 0x80 0x6C
Unfortunately ATtiny11 is a very old series which is almost completely forgotten with low specs and can't be programmed easily (ATtiny13 is the replacement).
Photos of a real ATtiny85 :
Photos of a fake (?) ATtiny85 :
It was the first time I faced a deliberate forgery. I certainly bought a fair share of fakes and clones, sometimes knowningly ("Digispark rev3", etc...). The first thing is certainly to run a test ASAP. Apparently sellers are keen to reimburse immediately when notified there ware is not genuine.
Then, to consider real distributors, like in the old days:
For example, for 5 x ATTINY85-20PU:
- AliExpress: estimated delivery 3 weeks => 7.22€ + VAT (in theory)
- Ebay (France): 48H delivery by post => 12€ inc VAT
- Reichelt Elektronic: Delivery 2-6 day => 13€ inc VAT
- Farnell Europe: Next day UPS delivery => 14.40€ inc VAT and surcharge if order < 30€ HT, only 6.12€ inc VAT otherwise
I always considered the "big" retailers (Mouser, RS, Farnell, Digi-key, ...) as professional only but in reality they seem more and more keen to accomodate small orders too. I far as I can tell, I could order a single unit for 9.50€ inc VAT and delivery. Not necessary the most cost effective but with a risk of counterfeit stuff certainly very low (but even for controlled supply-chains, the risk is never null).