mwwalk

Member Since: August 4, 2010

Country: United States

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www.TheWanderingEngineer.com

  • I tried this and it worked fine with my breadboard arduino. However, I looked up the datasheet from what is printed on the resonator package and it said it is 30pF capacitance but the ATmega328p datasheet says it needs capacitors of 12-22pF. Is this ok or am I missing something?

  • I believe there is an error on the datasheet for this part, specifically the value of 2.5mm in the pcb layout portion. Firstly, all of the similar parts on mouser have 2.1mm for this dimension. I know this isn’t definitive but all the other dimensions are the same so I have a hard time believing that is off. Secondly, if you look at on the datasheet, it looks like a smaller dimension than the 2.4mm that is near it. I took the pdf into photoshop and measured the distances and I calculate that it should be 2.1mm. Now, I know that the figure could be off but that would be a pretty big coincidence. However, if you look at the other dimensions of the data sheet you can calculate this same dimension to be 2.4mm + .45 so I have no idea what it should be. Would somebody at sparkfun take a look at the datasheet and let me know what is correct?

  • Yes. It should take about 15.6 hours to charge completely though.

  • For those of you that don’t want to read the datasheet, max charge and discharge is 1C, normal charge is 0.2C. The wire is 22AWG so it can carry up to 7amps. However, I believe the JST-PH connector is only rated at 2A, but I could be wrong.

  • This would have been a little more useful as a reply to j.tilghman question rather than it’s own comment. For those that see this is several years and don’t know what question he/she is answering it was: “Could you charge 2 of these packs in parallel”

  • Nevermind, I watched the video and answered my own question. No major changes but some nice minor ones.

  • Are there any major changes between this version and the previous version? (besides the prices, thanks btw)

  • 1) Thanks for carrying these, it’s so annoying to have to put a seperate order in to digikey for only a few things like this.

    2) I wish you’d carry more smd parts like these, especially in the 0805 size, which is the smallest my old eyes can work with.

    3) I think these should be pretty bright at 120mcd. For maximum current, use a 150 ohm resistor for 5V or a 60 ohm resistor for 3.3V. Though personally, I’d just use a 330ohm.

  • The easiest thing to do would be to use a knife to cut the small trace between the center pad and the 500mA pad. Then get a regular through hole resister and solder it into the “prog” space between the two JST connectors. Page 7 of the datasheet has a chart showing which resister to use to achieve a given output current. For 60 mA, you should use a 16k resister.

  • From the board, it looks like the battery in and system out are connected and just have different labels on them but could be used for either. Would somebody confirm that I’m not reading that wrong?

No public wish lists :(