First, I want to thank you for letting us use your EAGLE library. I like your library better than the standard libraries.
Unfortunately, there seems to be an error in the tiny45 model. And i discovered that way too late…
Total disaster. I put so much effort into this PCB. First time I did a surface mount board, so I was extremely careful, and put lot of effort into making it as small as possible, but still one layer and no jumpers. Now I have a useless card. I don’t know how many hours i put into this. All wasted.
According to the datasheet the GND is on pin 4, but in your model it’s pin 1. And the rest of the pins except VDD are on different places.
This really took the air out of me. I should had used the tiny13 model instead.
How could this happen? why did the designer move the pins which are on the right place on all other atmel 8-pin models?
Always check other people’s PCB parts before you use them, or create your own. I’ve just found some errors in a Pulsonix library: whoever created the footprints for a range of Molex SMT connectors misread the data sheet and got the mounting pad positions wrong.
FWIW I’ve built my own footprints mixing up the measuring units and accidentally letting my printer scale the image. So I did a print test and it looked fine, but when I bought some boards they turned out to be useless. That one had me kicking myself.
My latest board has a footprint I designed myself.
I failed to print it out 1:1 and place the parts on the printout to check the pin spacings.
The results are utterly predictable.
I don’t mind so much the $25 I spent to produce a beautiful coaster and learn a valuable lesson, but it’s going to kill me to have to wait another 2-3 weeks for the replacement.
Thankfully I already learned (the hard way) the “test fit all the parts before you solder any of them” lesson, so I didn’t throw any good money after bad.
sylvie369:
I don’t mind so much the $25 I spent to produce a beautiful coaster and learn a valuable lesson…
Funny enough, it turns out the pair of PCBs I got with bad footprints, together, were the perfect height to shim my new oscilloscope’s wobbly feet. So, mysterious forces… :mrgreen:
Whenever I use a library that I did not personally make, I like to do two things:
Use the view tool to highlight one pin at a time to highlight a trace on the board and trace it by eye. Make sure it is going where its supposed to go.
I print the final board out 1:1 scale and I lay any questioned parts right on the printed pads to check spacing. That way, when the boards come, there is no surprise about footprints being wrong.
I actually made a design earlier with the pins on the right place. I used a part from the standard library. But when I printed it on paper I discovered I had used a wrong size SO8 footprint. My tiny85 is in the larger package, but the footprint was for the smaller one. After I had changed the part I discovered the pins were in different places, but I just thought “a-ha! the bigger SO8 package got a different pin layout, I will have to make some changes to the board”.
