I have a board that i am soldering an atmega328 to. I burned the board pretty bad. see pictures. Is this still usable
Your pictures are so poor that I can't see what I am supposed to see.
sorry i will get better ones
see if this one is better?
Yes, usable as long as pins are not shorted out.
thanks. below is a picture of my supply that i am using to drive the chip. just a 7850. 10 uf on input .1uf ceramic bypass and a 220k for the led.
I mean 7805 lol
I dunno if i should have gone with the .33 uf or not. like the data sheet says. i have seen many debates on this.. i seen to have no stability problems . my power source is a 9 volt cell for this project.
I use whatever is handy, 10uF, 4.7, 3.3, for input, 1uF for output, not all that critical.
220K for LED? Surprised that allows enough current for an LED to light up.
Say your LED had 0V drop across it (vs 2.7V, 3.2V, whatever).
Then 5V/220,000 = .002mA, surelny enough to make an LED light up.
220 ohm, 2.2K, more reasonable.
Be sure to have 0.1uF on VCC pin of each device that will be powered from the 5V source.
wow i looked at the resistor. it is 220 ohm lol and i have an update i am adding a 3.3 volt regulator to the board with the chip.. thought it migh come in handy for tests.l. the lm 1117t handles the output from the 7805.
Got to watch signal levels interfacing with 5V powered '328P chip then.
Many devices have limit of IO signal no more than 0.5V above their Vcc level.
So 5V > 3.8V - problem. Will need a level converter chip for high speed signals (like SPI control), or resistor voltage divider if running it at slower speeds (perhaps I2C, or bit-ganging the signals). This one is popular for level conversions from 328P to other devices, and then the other device DataOut direct to 328P MISO input.
I am always concerned about 5V on MISO line during programming, so a buffer on DataOut from SRAM back to 328P would be a better design.
i was gonna use i2c. this project is gonna have several attiny's in it. the attiny85 is gonna be the little engine that could so to speak.
i actually have a couple o theese in my chips bin. lol
CrossRoads:
Then 5V/220,000 = .002mA, surelny enough to make an LED light up.
http://tinyurl.com/lbt42bz (you tube /watch?v=CIwlyy_KpXo)
If you have sensitive enough PMTs, you can detectible light with just a few nA.
edit -- when did youtube links start getting nuked?
Yeah, that comes in handy with the naked eye & diffused LEDs.
that is interesting. i dont have any scopes or anything. all i use is a multi meter.
With a 5.1K resistor, clear lens LEDs are very dim, good enough to see flashing while a download is occurring. With 220K and diffusion lenses, you wouldn't see anything.