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Messages - alextm

2
General discussion / Re: soldering tqfp-144
> The major problem with 0.5mm pitch is to properly align the part on the board and that's where quality of pcb is important. It is way easier to position part on a good board then on a shitty one

Oh yes, placing the parts is the most annoying part of soldering. It took me a while after the first time I tried soldering tqfp-0.8 and failed badly to even attempt anything quad again. Thankfully that was several months ago.

I also do have wick and use it constantly.

> don't make a common mistake of using super fine tip

I don't think that will be a problem ;)
3
General discussion / Re: soldering tqfp-144
It looks like while there are some differing opinions on how much of a difference it actually makes, I think I should be able to solder this without too much trouble.
brian, those videos were neat, I have seen solder do that on soldermask when I spill paste on it, but never realized FR-4 did that to it as well. I actually have everything here to try to reproduce that, but never thought of trying.
arhi, the wave tips look cool, and I can definitively see the point of those and how they work for controlling the solder. I may have to see if I can pick one of those up for my iron some time soon. That and some finer solder. My tool bench started out for through hole and is only slowly being converted to smd over time.

Everybody here has been quite helpful.
Thank you,
Alex
4
General discussion / Re: soldering tqfp-144
Yeah I have good flux and a high power iron, so then I guess I don't need to worry about it. My father's homemade boards were barely good enough for through hole parts, so I never have even tried to make my own boards for smd.
Thanks,
Alex
5
General discussion / Re: soldering tqfp-144
Sorry, let me be a little more clear. I have some boards from pcb sunday and such, and the soldermask on them is a father distance away from the pads than the fab I currently use for small boards. It looks like that distance will severely effect the solderability of the part. Mostly I was wondering if it Seeed's boards have soldermask between the pins of a 0.5mm part? None of the scans I found here really showed the pins in enough detail to be sure. Or alternately does it make a difference?
Hope that clears things up a bit.
--Alex

arupbsk, I have hand soldered .5mm pitch on boards with a soldermask between the pins.
6
General discussion / Re: Eridani: ARM USB OTG/HOST/DEV development board (LM3S365
[quote author="brian"][quote author="alextm"]I am planning on building a custom USB drive that handles at minimum the RSA side of the SSH protocol and preferably the whole process just sending and receiving packets to the host application which passes then directly to the network and sending and receiving text to the host application for interaction..[/quote]

Sounds like you are a good programmer. I have been interested in RSA like things on micros mostly because email transfer these days needs to be done over a secure layer. I find email a easy way to send command to internet enabled projects.[/quote]

I would not say "good", I would say learning with a hope to branch out. That would be my first real computer app, second USB project, and first or second crypto project, (depending on if I start on of my other AVR projects first).
7
General discussion / Re: Eridani: ARM USB OTG/HOST/DEV development board (LM3S365
I am planning on building a custom USB drive that handles at minimum the RSA side of the SSH protocol and preferably the whole process just sending and receiving packets to the host application which passes then directly to the network and sending and receiving text to the host application for interaction.

The basic idea behind this was to still provide a secure connection back to my SSH server (and thus my home network) on an untrusted machine without giving that machine any access to my private key or possibly even the session key.

I am currently an AVR hobbyist but recognize that it may not be the best way to make this project. I also would prefer to not have to make a ton of different boards and so a dev board that has a USB port on it will allow me to develop and figure this out before I make final form-factor circuit boards. Also, I prefer setups that have information on what and how to build things such that I have an idea of what I am trying to do before I hit the datasheet to find out exactly how to do it.
So yes, one of these would advance my project immeasurably.

Edit: Fixed formatting and added a line I forgot the first time.

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