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Forum section: electronics / general

author: @rt
author_rank: Super Contributor
timestamp: September 16, 2016, 03:27:46 am
content: 48 pin LQFP, of which 43 are connected, and 41 still need lead out.I give odds of 75% on this board in my favour

author: Ampera
author_rank: Super Contributor
timestamp: September 16, 2016, 03:36:42 am
content: Quote from: @rt on September 16, 2016, 03:27:46 amYou've got this. Time will give the perfect product. Unless you fry it with your iron.

author: Red Squirrel
author_rank: Super Contributor
timestamp: September 16, 2016, 03:48:34 am
content: Haha nice. I've tried hand soldering SMD and gave up, my tip on my Hakko is bigger than like 3 pins combined, and I can't seem to find smaller tips in Canada.

author: @rt
author_rank: Super Contributor
timestamp: September 16, 2016, 03:52:02 am
content: I had to get a tip for this.. not what I’d use for any other project.This is not at all sensible.. the completed Arduino compatible shield is only $10AU.Just a challenge, if I’m successful I’ll set it in some clear potting.

author: XOIIO
author_rank: Super Contributor
timestamp: September 16, 2016, 04:22:58 am
content: Quote from: @rt on September 16, 2016, 03:52:02 amIs that from adafruit or ebay? If you haven't, check ebay, you can get a pro mini for as little as $1.50 if you time it right.

author: @rt
author_rank: Super Contributor
timestamp: September 16, 2016, 04:29:36 am
content: Oh, I already paid $35 from out local retailer Jaycar in Australia, just to have a working one in a hurry.I wanted to start on software already since I’ve never used any mp3 decoder.

author: Karel
author_rank: Super Contributor
timestamp: September 16, 2016, 12:00:16 pm
content: A year ago I did something similar with a TQFP100. Didn't connect all pins though...

author: @rt
author_rank: Super Contributor
timestamp: September 16, 2016, 12:46:19 pm
content: Lol niceBecause you didn’t need many pins or didn’t finish it?They look like just ground pins on a copper ground plane, but I don’t know everything I’m seeing right.It also looks like a bunch of construction workers are holding up the chip if you look at it that wayThe manufacturer has relieved me of connecting another two pins, and potentially more, but I’ll see how I go.

author: JPortici
author_rank: Super Contributor
timestamp: September 16, 2016, 12:56:45 pm
content: Quote from: Red Squirrel on September 16, 2016, 03:48:34 amnot a problem. drag soldering + flux and copper strip. no chip have ever died on me, yet

author: @rt
author_rank: Super Contributor
timestamp: September 16, 2016, 01:31:19 pm
content: I totally missed that. This is not surface mount soldering!Just one of Dave’s videos could change your life. This tip is wider than 3 pins too!

author: Red Squirrel
author_rank: Super Contributor
timestamp: September 17, 2016, 07:25:38 am
content: My issue when I tried was that I was doing it in free air, I imagine it's easier on a board as solder tends to want to not flow on solder mask and you have a proper area for chip to stay put once you can tack an end. Been meaning to learn Ki Cad so I can draw some breakout boards and have them made. I have lot of components I want to play with but ridiculously under estimated how hard it would be to dead bug them when I originally bought.

author: rstofer
author_rank: Super Contributor
timestamp: September 17, 2016, 03:06:27 pm
content: Quote from: Red Squirrel on September 16, 2016, 03:48:34 amPut some paste flux along the pins. Just run a string all the way around the chip using a syringe (like the paste comes in).Using a fairly large tip, put a small blob of solder on the tip and run the tip across the pins. When you run out of solder, apply another blob.Seriously, you don't solder these things pin by pin. You 'drag solder' the entire package. The package in the picture has fairly wide pin spacing. It will be unlikely you would get a solder bridge. If you do, a little solder wick will pull the solder off.You would usually tack to opposing corners before starting the drag operation.

author: matseng
author_rank: Frequent Contributor
timestamp: September 17, 2016, 03:07:00 pm
content: Like 10 years ago I did this mega168/smd to dip hack by soldering 32 wirewrap wires to the pins down to the socket. Unfortunately it seems like I forgot to take a picture of it before bukkakeing it with hotsnot... ;-)

author: homebrew
author_rank: Frequent Contributor
timestamp: September 17, 2016, 09:08:23 pm
content: You have totally missed out the good old Elm Chan ...http://elm-chan.org/docs/wire/wiring_e.htmlI guess I'll never be at that level of perfection ...

author: rob77
author_rank: Super Contributor
timestamp: September 18, 2016, 12:18:41 am
content: Quote from: amyk on September 17, 2016, 03:09:54 pmwatafak

author: @rt
author_rank: Super Contributor
timestamp: September 18, 2016, 04:44:56 am
content: Oh no! One of the leads on that BGA is broken!Those are things of beauty, unlike mineI haven’t wrecked it yet though, despite how it looks (unless ESD or dwell time has killed it).The pins can be staggered, either lift a pin, or not, so it’s really a 3D object that you can’t see here.3/4 done, the last row is the analogue output and supply where I’ll try to be more careful.

author: @rt
author_rank: Super Contributor
timestamp: September 18, 2016, 07:53:30 am
content: Hopefully get to test tonightQuestion: Is the potting used for China chip on board any different than the self mixing stuff sold at RS in small quantities?Or any different than the potting used to fill enclosures?

author: SeanB
author_rank: Super Contributor
timestamp: September 18, 2016, 08:40:23 am
content: No different, most PCB potting compounds will work, but I would there on your board rather use a flexible potting compound, so that thermal stress does not crack the leads off the solder.If it works then first clean the flux off, test again and then use a blob of a flexible compound, like Pratley flexiseal, to encapsulate it, or a flexible conformal coat.

author: @rt
author_rank: Super Contributor
timestamp: September 18, 2016, 09:19:17 am
content: OkThanks for the replies. I’ll have to do something quick. It’s corroding as we speakIs the resin in solder to be removed only because it won’t stick?This is assuming it’s not burned to carbon, and could conduct.I could wash it in alcohol which won’t remove everything, but there are plenty of places I can’t touch.

author: @rt
author_rank: Super Contributor
timestamp: September 18, 2016, 06:28:53 pm
content: It’s just increased a lot lot in personal value now it worksNot first go, but after fixing a mistake in installation (not this module itself) swapped SPI clock and data out,and also the crystal oscillates intermittently when set up with the 33pF cap values in the data sheet example.It works reliably now I have only disconnected one of them from ground which surprises me.I was going to go all the way to swapping both for 22pF, but the first disconnection I made had it working reliablyNow it also means I should spend the money on good goop since I’d really get into Eagle CAD more than do this again,So I’ll look into the MG Chemicals, so long as it’s not an unreasonable minimum to buy.

author: @rt
author_rank: Super Contributor
timestamp: October 08, 2016, 01:42:56 pm
content: I never did follow this up... bam!!It’s audio coupled through earphones sorry!

author: bitslice
author_rank: Frequent Contributor
timestamp: October 08, 2016, 03:00:26 pm
content: why would anyone do that?just buy the relevant PCB adapter, they are available for every package type

author: zapta
author_rank: Super Contributor
timestamp: October 08, 2016, 04:10:04 pm
content: Quote from: bitslice on October 08, 2016, 03:00:26 pmAnd they are very cheap on ebay. E.g. 5 units for $2 shippedhttp://r.ebay.com/wxqq6I

author: @rt
author_rank: Super Contributor
timestamp: October 09, 2016, 02:44:24 am
content: Yeah I know right... and for under $10 you can get thishttp://www.ebay.com.au/itm/VS1003-MP3-Module-Development-Board-supports-MP3-Decoding-On-board-Microphone-/361455471150?hash=item54286cca2e:g:-YIAAOSw1S9We~bD

author: Karel
author_rank: Super Contributor
timestamp: October 09, 2016, 06:26:17 am
content: Quote from: bitslice on October 08, 2016, 03:00:26 pmI never used them for the reason that I can't put the powerline decoupling capacitors close enough the chip.

author: iampoor
author_rank: Frequent Contributor
timestamp: October 09, 2016, 08:11:41 am
content: Quote from: bitslice on October 08, 2016, 03:00:26 pmSome electronics hobbyist's have masochist tendencies.

author: fubar.gr
author_rank: Unknown
timestamp: October 09, 2016, 10:12:41 am
content: Quote from: @rt on September 18, 2016, 07:53:30 amKudos for making it work, but I personally wouldn't follow this approach.In my opinion for a circuit of that complexity it would be much simpler to design the PCB on a CAD package like eagle or kickad and order the board through a service like OSHpark.

author: @rt
author_rank: Super Contributor
timestamp: October 09, 2016, 10:41:32 am
content: ThanksI desoldered the chip from a perfectly good China moduleI think it’s a bit better than the adapter board could turn out, but I should have followed the suggested layout of a ground plane.The adapter boards here are a bit better because they are made for the exact 48 pin LQFP only, and are also smaller.