My first Arduino (from China) - Page 1
Forum section: electronics / general

author: kalel
author_rank: Frequent Contributor
timestamp: June 14, 2017, 03:52:02 pm
content: I just wish to share - I've received my first arduino (or arduino-compatible, I'm not sure how they're called) board from China for about $3, if you're unsure if you will be able to use such a device at all, at least it's quite cheap if things don't work out.For someone with no experience whatsoever with microcontrollers, it was really straightforward so far (plug in, download drivers for ch340, install Arduino IDE and run the "LED Flasher" example), and it does exactly what my first 555 circuit does, although I'm quite sure it doesn't work at the same frequencies. On the other hand, it's much simpler to type in some delay values comparing to turning the potentiometer and "observing" or measuring resistance/capacitance and then trying to calculate the rate.I did not check all of the IO ports (not even sure how to do that yet) but I'm hoping that they will all work.A lot to learn, and hopefully have fun on the way.

author: technix
author_rank: Super Contributor
timestamp: June 14, 2017, 04:08:54 pm
content: This thing should work with normal Arduino environment. Enjoy hackingp.s. What does the 8-pin chip say?

author: Nusa
author_rank: Super Contributor
timestamp: June 14, 2017, 04:17:53 pm
content: The board is basically a breakout board for the atmel chip...if the chip works, the ports work. Nearly everything else on the board is for usb and power.You can put a potentiometer back into the equation if you want. Check out the AnalogInput example.

author: kalel
author_rank: Frequent Contributor
timestamp: June 14, 2017, 04:29:04 pm
content: Quote from: technix on June 14, 2017, 04:08:54 pmI took out my cheap 0.3 mp USB microscope (I think about $16 some time ago) with a plastic stand which broke 2 times and I had to superglue (holds well so far, superglue is holding the plastic better than it held itself!), anyway, here are some screenshots:Some components (I had to decrease exposure here to reduce LED glare)Curious, what is the "AA" element?All in all, this cheap microscope seems to be useful for electronics. For sure, it can see small things better than me.Edit:Quote from: Nusa on June 14, 2017, 04:17:53 pmGood idea, thanks! Definitely work exploring.

author: donotdespisethesnake
author_rank: Super Contributor
timestamp: June 14, 2017, 04:29:38 pm
content: Quote from: technix on June 14, 2017, 04:08:54 pmIt's CH340G, I think.Lol, ninja'd!Doh! I can't count past 5

author: technix
author_rank: Super Contributor
timestamp: June 14, 2017, 05:04:19 pm
content: Quote from: donotdespisethesnake on June 14, 2017, 04:29:38 pmCH340G is a 16-pin chip...

author: kalel
author_rank: Frequent Contributor
timestamp: June 14, 2017, 10:03:43 pm
content: Now that I have taken those screenshots, I can at least search the ICs to see what they're for.Yes, I don't already know by name what each chip does, even these likely very common ones - sorry.AMS is to provide voltage references, but what is the mentioned 8 pin LM358 for?From wiki:"The LM358 is designed for general use as amplifiers, high-pass filters, low band pass filters, and analog adders."Which of those functions is it serving here? I'm assuming it's not HP/LP filtering (although I might be wrong - maybe it is there just to remove some noise), so that leaves Amplifier (but amplifying what, input signals?) and it's probably not an analog adder, but when you say "it's probably not this" without knowledge, you are more likely to be wrong than right!

author: Mr.B
author_rank: Unknown
timestamp: June 14, 2017, 10:50:13 pm
content: QuoteLooks like the clock crystal for the ATMega328p MCU.

author: kalel
author_rank: Frequent Contributor
timestamp: June 14, 2017, 11:30:53 pm
content: Quote from: blueskull on June 14, 2017, 10:52:03 pmThanks! It did look like that, but I wasn't sure since there was a much larger element with 12.000 marking. But there are two chips (the other being CH340G) so perhaps they both have their crystals. The "AA" one is so small, that I would barely see it, yet alone be able to read that text without the microscope.

author: sleemanj
author_rank: Super Contributor
timestamp: June 15, 2017, 12:57:41 am
content: Quote from: Mr.B on June 14, 2017, 10:50:13 pmIt will be a ceramic resonator, I'm not aware of any crystal packages that small, specifically it is probably a Murata Ceralock CSTCE, I have a strip of 16MHz ones in my drawer and they are marked similarly except AJ instead of AA.I don't know why they would have added capacitance to it as that series has capacitance built in, probably the designer swapped out a crystal for the resonator and left the caps in.