I'm giving away 2 MegaMini's

Mowcius, how much do you need?

Well by the pack that jerryb got, looks like I won't be needing any. I need it for the project that the board is for so I will be fine.
I'll buy myself a few new rolls of the stuff soon.

Mowcius

Do you have a cheap address for heatshrink? I think I am paying too much ;).

Do you have a cheap address for heatshrink?

This is the assortment pictured above... http://www.jkdevices.com/heatshrink-kit1 It woud probably be about $3 to ship

$6 for assortment + $3 for shipping = $9 total.

Not sure if this ends up being a better price for you or not. I can also make custom assortments... just tell me what you need.

Thanks for the offer Jeff K, will keep it in mind :). At this moment I don't need any heatshrink, was just informing in case I need some ;).

It arrived!
Thanks a lot jeff.

Here's two pics:

I will let you know how I get on with it all.
Are the LEDs common cathode or anode that you sent me too?

The heatshrink is also a very nice pack. Good selection and a decent amount. Should keep me going for some time.

Mowcius

Great pics guys!

Are the LEDs common cathode or anode that you sent me too?

I am pretty sure they are common cathode. I got a few hundred of them off eBay but they had no specs so I had to guess.

NOTE: Images are pre-production images. Actual product will appear slightly different. The USB orientation will be horizontal NOT vertical as shown in the picture and there will be a TX/RX LED for the USB.

Maybe as you have changed the images, you want to change this statement :wink:

Mowcius

you want to change this statement

Thanks for catching that... done.

Thanks for catching that... done.

No problem, you got any further info hiding anywhere? I saw your product datasheet and the ATmega1280/2560 datasheet tells me pretty much all I need to know but I was wondering if you had written up any more info anywhere.

Probably going to solder some headers on and do some tests tonight if I get round to it.

Mowcius

you got any further info hiding anywhere?

I'm working on it. I will try and have something this weekend. Mainly a BOM and some more specs on the regulator. I am testing different voltages and current draws to see what the regulator can handle without a heatsink. I can say that 12 volts with nothing else hooked up gets it pretty hot. But I don't really see too many people trying to power it with that high of a voltage.

Also there are some differences in the way the FT232 is hooked up. Mainly the pin used for RX/TX.

I'll try and get a schematic too. I'll have to make it from scratch because this board was designed in the PCB layout area without a schematic. It was also designed in PCB Artist to speed up development and take advantage of some discounts at 4pcb.com.

Ahh, ok, no worries.

I went and cut some headers for it today (not soldered them yet) and I just thought to myself:

So many I/O pins....
It's like Christmas! ;D

Mowcius

thats a pretty good quote for an arduino t-shirt don't you think?

for an arduino t-shirt

You mean the MiniMega t-shirts launching out of my t-shirt cannon?! Oh wait.... time to make a t-shirt cannon!

You mean the MiniMega t-shirts launching out of my t-shirt cannon?! Oh wait.... time to make a t-shirt cannon!

Haha, if only we still had sigs. It'd make a nice sig quote at least.

More MegaMini pics coming later, I haven't got any closer to actually coding for it yet though :smiley:

Mowcius

Right, headers on (noticed you can only them on one side (the one closest to the USB connector on the left would hit the crystal if you tried to put them on the other way round.

First test, blink sketch on pin 13. Had to work out where pin 13 was but not too much of an issue. All seems to be working well.


Suggestions:

  • Move crystal slightly more towards the middle to allow headers (and connected cables) on either side. This is probably a right pain to try to fit all the tracks and other components around though. :stuck_out_tongue:
  • Tell me what the second LED's for, I thought it'd light up during upload but no... :wink: Is it meant to?
  • Possibly sell with cables (an an option) or stock them in your store. 2x10 and 2x8.

Mowcius

allow headers (and connected cables) on either side.

Planned for the next revision... most likely will be a smaller crystal. The first version had the crystal covering half of one of the holes. So it is progressively getting better. Initially I planned for the headers to only be installed the way you have, but the more I though about it, the better it would be to install them on either side.

Possibly sell with cables (an an option)

I have some ideas for this. I don't want to just dell cables. If it is something I am selling, I want it to be a little more sophisticated. At a minimum, cables with a single row breakout on one end that will work with a breadboard.

I thought it'd light up during upload but no... Is it meant to?

Yes it is. hmmm... I am pretty sure I tested those LED's before I sent the boards. How to debug...

First thing to check is if I didn't reprogram the FT232. You can download a config utility from FTDI's website that allows you to configure the CPIO pins of the FT232... CPIO3 should be set to RX/TX. But now that I think about it, the default is PWR so it should stay lit if I didn't reprogram it.

Next, maybe make sure I didn't install it backwards. If compared to the power LED it should be flipped 180 degrees.

Last thing I can think of is maybe that pin of the FT232 isn't making contact with the board. I guess first try putting some pressure on the FT232 while uploading a sketch and see if that helps... otherwise maybe put some solder paste on the pins and run your solder iron over all of them. (make sure you have some solder wick on hand... just in case :wink: )

If none of those solve the problem... then maybe the resistor or LED is bad.

Thanks for the suggestions and hopefully you can solve the TX/RX LED puzzle.

One other idea I had was something I will call MegaMini Stackers. You can have the option to get a MagaMini Stacked with some sort of shield. Essentially it would be a board exactly like the MegaMini, soldered on either the top or bottom. This board would then have something on it... gps, accelerometer, etc. Kind of like a permanent shield. Not sure about the permanent part yet, but I think you get the idea. I like the permanent soldered idea because it wouldn't add much thickness to the boards. Just 2 pcb's making an Atmega sandwich.

Almost looks like those old IDE cables! :smiley:

Initially I planned for the headers to only be installed the way you have, but the more I though about it, the better it would be to install them on either side.

Well I want them this way round with the USB port the right way up but it doesn't matter much. It does mean that you could have less on the 'bottom' of the PCB then, only the chip and some soldered ends of headers.

At a minimum, cables with a single row breakout on one end that will work with a breadboard.

Anything like that sounds like a good idea. Cables for when you want to stick it in a project. It is nicer to solder headers and then use a cable with connector than solder a load of wires into tiny holes on the board.

Yes it is. hmmm... I am pretty sure I tested those LED's before I sent the boards. How to debug...

Thought it was probably meant to.

First thing to check is if I didn't reprogram the FT232. You can download a config utility from FTDI's website that allows you to configure the CPIO pins of the FT232... CPIO3 should be set to RX/TX. But now that I think about it, the default is PWR so it should stay lit if I didn't reprogram it.

Right, I think I'll give that a miss to start with then.

Next, maybe make sure I didn't install it backwards. If compared to the power LED it should be flipped 180 degrees.

Yep, it is 180deg from the rotation of the power LED.

Last thing I can think of is maybe that pin of the FT232 isn't making contact with the board. I guess first try putting some pressure on the FT232 while uploading a sketch and see if that helps... otherwise maybe put some solder paste on the pins and run your solder iron over all of them. (make sure you have some solder wick on hand... just in case :wink: )

I'll try this at some point.
[edit]No luck with this. All the connections look fine too.[/edit]

If none of those solve the problem... then maybe the resistor or LED is bad.

Maybe.

It's not a real issue. The computer tells me when it's uploading. I'd rather have it not working than spend hours trying to remove a solder bridge on the FTDI chip while trying to sort it :smiley:

I like the permanent soldered idea because it wouldn't add much thickness to the boards. Just 2 pcb's making an Atmega sandwich.

Sounds pretty good. I have thought of board sandwhich a few times, soldering some headers directly through an arduino pro board or something.

Almost looks like those old IDE cables!

Yeah but more expensive, they're something like £2.50 each if you buy them singularly :o
Glad I got mine free (well the 2x10s, I need to buy some 2x8s or I might be able to get some of them cheaper.)

Mowcius