[carpe] 2016-10-18 CARPE Conscribillati: Arduino Zero Boards; Soldering: Touch Iron to Board Longer to Get Joint Hot Enough
jep200404 at columbus.rr.com
jep200404 at columbus.rr.com
Sat Nov 19 18:32:29 EST 2016
Larry Howell compared boards from different Arduino Zero boards.
based on same Atmel ARM Cortex M0
about six times performance of any ATmega chip (328 or 2560 (20+ years old))
3x faster clock
32-bit instead of 8-bit
twelve 12-bit ADC channels
wants to measure home electrical power
3.3V I/O, even though header pins can be same
7mA versus 40mA of mega
symmetric source or sink
more ram
usb 2.0 otg
six serial ports
USART
I2C
SPI
I2S (for sound)
much DMA (great for much ADC)
integrated capacitive touchcontroller
48 pin package
12x10 touch controller
64 pin package
16x16 touch controller
builtin CRC32 generator
watchdog timer
single wire debug interface
Arduino Zero $50 from arduino.cc (Arduino LLC)
29 I/O
12 12-bit ADC
1 10-bit DAC
extra chip adds another USB port
atmel embedded debugger
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soldering
concept of joint surface cleanness
what beginners perceived as clean was not as clean as needed
the soldering tip
setup:
Wait for soldering iron to get hot.
This usually takes longer than you want,
especially if you are a beginner.
Soldering irons that are not hot enough are frustrating.
You just have to wait for it to get hot enough.
If using bare copper tips, (re)file the tip to the desired shape.
(solder dissolves bare copper,
so bare copper tips require occasional filing)
I use a "chisel" shape tip:
two flat faces with about 45 to 60 degrees between them
If using iron plated tips, do NOT file the tip.
The whole point of iron plated tips
is that they maintain their shape without refiling.
This is because solder does not dissolve iron.
Once the iron coating is gone, either through wear or filing,
the inner copper will dissolve and the tip will be ruined.
Get tip wet with solder
The point of this is that a thin film of solder
is what actually conducts most of the heat
from soldering iron to joint
(without applying much solder to the joint).
Usually, one applies rosin core (flux) solder to the tip,
then removes the excess solder,
so that there is just a thin film of solder left on the tip.
I remove the excess solder by whacking the handle on the table top.
This is abusive to the soldering iron,
but gets rid of excess solder to my satisfaction
while leaving some of the desireable rosin flux.
Most folks remove the excess by dragging the tip across a wetted
sponge. I have not had good success with this popular technique.
For me, the solder is often just pushed around to the other side of
the tip. Also, it removes flux, but I want the flux to remain.
Touch the tip of the soldering iron to a joint.
for best heating:
Get flat face of tip flat against flat face of pad.
You want maximum contact area with smallest gap.
The thin film of solder on the tip
is what conducts most of the heat.
The purpose of the soldering iron is to apply heat to a joint.
Although applying solder is _not_ the purpose of a soldering iron,
often a little bit of solder from the iron goes to the joint.
That little bit of solder is OK.
No pressure is required, mere contact is good enough.
So be gentle, don't push.
Wait for the joint to get hot enough.
Learning what is hot enough is what takes experience.
If the copper pad is already tin plated, watch it melt.
Usually solder and tin are shinier when melted.
Watch the little bit of solder on the tip to flow on the pad.
Often after seeing the initial melting of plating on the pad,
one waits a few seconds more for the joint to be actually hot,
instead of just barely above melting temperature.
Add solder from a different side of the joint.
Gently touch the joint with solder.
When the joint is hot enough it will melt the solder.
When the joint is hot enough and clean,
it will suck the solder into the joint.
surface tension and capillary action
will "suck" solder into and around the joint.
Don't push solder into the joint.
Pushing solder into a joint does not make the joint bad,
but can hide a bad joint.
Only a hot clean joint will suck the solder into the joint,
so if the joint is sucking the solder into the joint,
you likely will have a good joint. So just gently apply the solder
and let the joint pull it into the joint. If the joint is not
pulling the solder into the joint, then the joint is either not
hot enough or not clean enough.
As a plated through hole fills up with solder,
it will help conduct more heat through to the other side.
When there is a nice concave meniscus curve in joint,
and the joint is not sucking in more solder,
remove the soldering iron.
I usually watch the meniscus from a corner of the joint
other than where the soldering iron tip is
and other than where the solder is being applied.
The tip heats pad, which heats plating through the hole and even on to
the pad on the opposite side.
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soldering clinic
It seems that a problem novice solderers had was not waiting long enough
for soldering iron to get the joint hot enough. They would remove the
soldering iron too early.
anonymous guy:
it's hard to use too much flux
one solderer
ZERO LiPO (for Pi Zero)
not enough flux, or not enough heat
probably not waiting long enough for joint to get hot
solderer repeatedly pull iron away prematurely,
not letting joint get hot enough
another solderer
some ESP8266 based little board from seeed for $8? at microcenter
Seeed Studio WiFi Serial Transceiver Module Breakout Board with ESP8266
seeed: 721092
sku: 007849
upc: 618996988358?
ESP8266 chip
serial EEPROM or flash chip?
crystal?
RF socket
all joints were bad
either not enough heat or not enough flux
i suspect not enough heat is more likely the problem, not lack of flux
wp: prefix means Wikipedia
To get good answers, consider following the advice in the links below.
http://catb.org/~esr/faqs/smart-questions.html
http://web.archive.org/web/20090627155454/www.greenend.org.uk/rjk/2000/06/14/quoting.html
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