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[Reply #270 on:]

All parts ordered except the stencil. Waiting to get confirmation from itead's factory that it is producible, then will order the stencil. Hopefully assemble the first board(s) the weekendof July 9 with Skyjumper's help.

[Reply #271 on:]

New Boards are in! "Bobuino" for lack of a name - never did come up with a name to put on the silkscreen!
Already have plans for this weekend, should be assembling next weekend.

Submitted order of 10 to itead June 28, received 12 today July 15

[Reply #272 on:]

  Wow very nicely done! With the risk of sounding needy could you keep track or photo the order in which you apply the parts to that board? I have read most of the thread as you have designed this and it is amazing how many parts you have managed to put on the board! My guess is that you would have to apply parts in a particular order otherwise you will have great difficulty.

  I probably don't need the latest greatest board but, I would still like to have because, it sounds so cool!


Mark

[Reply #273 on:]

"order in which you apply the parts to that board"
Well,  being surface mount, I imagine all the surface mount parts will be applied first, then flowed in the oven, and the  thru hole parts will be hand soldered in.
I would imagine start on one corner of the board and work across, or perhaps do all the caps, then all the resisters, then the LEDs, then remaining big parts.
The only part I think will be difficult will be getting a microSD on the back of the card after the top is reflowed. The pins on the backend are tiny, but clearly exposed, so maybe not that bad.
itead studios seems to have built a nice PCB for me, so it looks like I have a good base to apply the parts too. Now I just need better eyes for plopping those parts down 

[Reply #274 on:]

   Thanks for the reply.
 
  "Now I just need better eyes for plopping those parts down  smiley-grin"

 I have yet to try soldering SMT parts and I dread the though of soldering them down. I do need to learn it at some point though.  I have a cheap magnification visor I found at a hobby shop and I have access to a magnifier with a light at work. Looking at my new Mega I can already see that a magnifier is a MUST for me.

Mark

[Reply #275 on:]

In the pre-SMD days you would normally load parts in order of their height, lowest through to highest. This way you could flip the board over to solder without them falling out.

That probably still applies to the PTH parts, with SMDs going on first.

______
Rob

[Reply #276 on:]

We can try a few things. Yes we can try to hand solder the micro-SD socket. We might be able to reflow the mocro-SD socket first, then flip it over and reflow the rest, with suface tension holding the bottom part on. I don't think that will be feasible, though. Because reflowing the top measn using the stencil and squeegie to apply the paste and I doubt we can do that with the micro_SD part applied.

Maybe the trick will be to reflow the top, then use the hot air rework station to apply the bottom parts. As I think about it that might be best, although we'll need to be careful to apply just enough heat in just the area we need, so the parts on the other side stay put.

As for the order of parts, most recomendations I have read are to put the big ones on first followed by smaller ones. I have found with only a few exceptions, it does not make much difference. My board has a few spots where that is better though. I make a checklist, have an enalrged gerber next to me, use a few magnifiers and its off to the races! The checklist is key though.

[Reply #277 on:]

  I appreciate the tips and ideas on applying parts. I have been able to solder since my teens so, over 20 years but, I know that I still have many things to learn. Recently, I have been soldering a lot and I have been finding little things that I wish I would have known in the past.  Some of my past work looks very sloppy compared to now.


Mark

[Reply #278 on:]

Thanks Skyjumper. Next weekend going to work for you?
Can you send me your checklist? I'll make one up for my board, and some expanded pictures also.

[Reply #279 on:]

Just stumbled onto this and it looks very interesting. I was looking to start using the 1284p so if i could get it in an arduino compatible board that would be great. I will keep an eye on this thread and hope all the assembly goes well.

[Reply #280 on:]

Thanks Subterranean, I am looking forward to attempt ass'y on Saturday.

[Reply #281 on:]

..nice boards.. I would assembly the very first pcb manually, and in a step by step manner. In case of errors it could be difficult to debug when fully assembled. E.g. start with power, ftdi, 1284p and so on.. and measure the voltages, currents.. just a hint.. Pito

[Reply #282 on:]

..nice boards.. I would assembly the very first pcb manually, and in a step by step manner. In case of errors it could be difficult to debug when fully assembled. E.g. start with power, ftdi, 1284p and so on.. and measure the voltages, currents.. just a hint.. Pito

I usually do this with any new board. It avoids any unnecessary hair pulling when something is not working!

[Reply #283 on:]

Not sure quite how to do that with surface mount. Need to stencil on the solder paste for the Rs, Cs, LEDs, USB connector, SD connector, and surface mount ICs, especially the FTDI chip. 

[Reply #284 on:]

  ..you need a flux only.. there is nothing on the board one can not solder manually.. just put a lot of flux (i.e. amtech 223), place the ftdi or other chips/r/c and solder the pins.. it is easy.. I am soldering 0.5mm 64pin chips - no issues by today.. P.