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Topic: BreadBoard to Circuit Board - MIssing the link (Read 6128 times) previous topic - next topic

runaway_pancake

Place the board that you've prepared into the dish of etching fluid.  Since it's your first time it would be wise to have it face up.  Be patient, this takes some time.  Every so often you can rock it gently to dislodge any air bubbles on the surface of the board.
It seems to me that either you have not actually etched a board yourself, or you are using an etchant very different to that I have used (Ferric Chloride).  If you just let it sit or rock it gently nothing will happen except that the resist will eventually lift.

It is generally necessary to use a bubble etch system with an airstone at the bottom of the (vertical) tank evenly aerating the board, or agitate the board quite vigorously in the hot solution.
I've etched boards using ferric chloride, never had a bubbler or heater.  Shallow plastic tray, copper side up, enough solution to cover and maybe again as much more, rocking that back and forth casually and constantly.  Works pretty good, maybe 15 min as I recollect.
[But, I agree that its just laying there, "soaking", does no good.]
"Who is like unto the beast? who is able to make war with him?"
When all else fails, check your wiring!

KenF

Place the board that you've prepared into the dish of etching fluid.  Since it's your first time it would be wise to have it face up.  Be patient, this takes some time.  Every so often you can rock it gently to dislodge any air bubbles on the surface of the board.
It seems to me that either you have not actually etched a board yourself, or you are using an etchant very different to that I have used (Ferric Chloride).  If you just let it sit or rock it gently nothing will happen except that the resist will eventually lift.

It is generally necessary to use a bubble etch system with an airstone at the bottom of the (vertical) tank evenly aerating the board, or agitate the board quite vigorously in the hot solution.

You have not mentioned what to do after etching - return the etchant to the bottle or dispose of it (how?).


What absolute BS.  Ferric chloride DOES dissolve copper.  With or without bubbles.  I've etched many boards with just such a method.  Has someone been selling you watered down etchant?  Warming the solution helps but even that is not essential.

As for waste disposal?  Do I come across as a Health and Safety officer? 

KenF

I've etched boards using ferric chloride, never had a bubbler or heater.  Shallow plastic tray, copper side up, enough solution to cover and maybe again as much more, rocking that back and forth casually and constantly.  Works pretty good, maybe 15 min as I recollect.
[But, I agree that its just laying there, "soaking", does no good.]
Thank you Runaway_Pancake. 

BTW just sitting there still works, it just takes longer.  Also without ANY agitation at all you can get some nasty side effects from bubbles.  At ambient room temperature, with a bit of rocking every 5 minutes or so takes about 40-50 mins. 

ConfusionSaysASK

Tylernt, you are right. I agree. But for lack of a volt meter at the time and using an the old school technique of observation also known as putting your finger in the socket I realized that was the case. I did also look up the white paper on the 74HC595 and it does say that it has built in resistance.

TomGeorge, the resistors I removed were the 220 ohm recommended in the following example
http://arduino.cc/en/tutorial/ShiftOut
and the blue ones were about the same as they came with those leds.

Paul_B, I have never etched a board before. That may be the next thing to learn. For now I am perfboarding it.

Grumpy_Mike, If you mean in the first picture, that capacitor was on another board but not connected to the project those pictures were of.

Grumpy_Mike

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I did also look up the white paper on the 74HC595 and it does say that it has built in resistance.
No I think you misunderstood that one.

tylernt

I did also look up the white paper on the 74HC595 and it does say that it has built in resistance.
Link? The 74HC595 datsheet I've seen has a rated maximum current but the chip itself does not provide a limit, an external resistor does that.

ConfusionSaysASK

Grumpy_Mike - Please clarify then. Additionally at this point things are progressing. I am happy to say I have made my first soldered perfboard of a portion of the project. And it actually worked! Ya I was skeptical it would too.

Tylernt - http://www.nxp.com/documents/data_sheet/74HC_HCT595.pdf is the link. Table 9 Page 15. RL = 1kohm.  There is a chance I misunderstood what they meant by it since I am just learning but that was enough for me to decide to pull the resistors.


Grumpy_Mike

#22
Nov 12, 2014, 08:16 am Last Edit: Nov 12, 2014, 08:21 am by Grumpy_Mike
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Grumpy_Mike - Please clarify then.
I think it is you that needs to clarify things. You think the chip has internal resistors. It does not.

Therefore you have to tell me what you think you saw in the data sheet ( it is not called a white paper ) that caused you to think this. Then I can tell you what mistake you are making.

Quote
Table 9 Page 15. RL = 1kohm.
that is a test circuit RL and all the other components are what you add to the output in order to test it. It is not built into the chip. They are the parts that are used to obtain that graph. Any change in those values in your actual circuit will change that graph.

ConfusionSaysASK

Grumpy_Mike - Sounds good and now I know! Thanks! Unfortunately that was the logic I used to do what I did and fortunately it worked. When I get a minute I will post a circuit diagram for you to look at. This way your learned mind can help me figure out why it worked?

pwillard

This is often the case... where lack of knowledge and the fact that it worked are translated into... "It's working perfectly" which in fact, is far from the truth.  It may be working, but working as you wanted it to can be far from working perfectly. This translates into wonderful things like...  "Why did My arduino pin die?" or   "It worked fine for a few weeks but now it's stopped working... should I just buy a new shift register?" (answer: no, you need to fix your design)

The datasheet is a mystifying document to newcomers and it's easy to misinterpret unless you have spent some time understanding what the manufacturers are trying to tell you.  For example, reading Maximum ratings as Nominal ratings is a common mistake.   Your goal as a circuit designer is to NOT attain the MAX ratings in your design... but to actually *avoid* them.

ConfusionSaysASK

PWillard. Makes sense as well as being nicely put. I now have a volt meter and will be taking measurements that the naked eye cannot see alone and the tongue test isn't best suited for. Good times all!

Grumpy_Mike

When I get a minute I will post a circuit diagram for you to look at.
Still waiting. A photo of a pencil drawn schematic will do.

ConfusionSaysASK

So here is part of it. Doing this piecemeal so I can round out the skills needed and put each part to bed before moving onto the next. Attached are three pictures. The schematic for this is basically the shiftout example 2 minus the resistors. http://arduino.cc/en/tutorial/ShiftOut I have soldered it in such a way that the pictures are easy to follow in relation to the tutorial. Now the following questions have surfaced. My test code is attached as well.

Continuity testing was not under power. Both LEDs were working LEDs when powered.
1)   I continuity tested one of the LEDs and got a beep. I continuity tested another led and did not get a beep, why? I do get a voltage reading on both though. Why is that?
2)   When you touch the leads to the LED legs does the electricity also flow down the anode and cathode into the circuit? Some of the LEDs display as .814volts and others 1.4volts even though the LEDs come from the same batch.
3)   In the continuity test on the circuit, why will the LED not light up even though it will light up when you do the test on the same LED before it is soldered to the board? (Does this have to do with Question 2 as power loss via dispersion throughout the circuit?)
4)   What is a simple way to test if a multiplexer is working? Can this be done with a multimeter?
5)   How come certain LEDs light up brighter than others?
6)   Why do four LEDs not light up even though they test positive on a continuity test.
7)   If a LED was melted because it was overloaded, would it pass a continuity test? What if it was connected to a circuit and it had a way to get the electricity back to the other lead through the circuit?
8)   Any way to test if I got the anode and cathode backwards?
9)   If I cut a LED off its legs can I solder a new one back on and more importantly will it work?
10)   Can I just solder a resistor into the anode leg of a LED to save space? Take out a section of the leg and solder in the resistor?
11)   Why are LEDs on when I plug the USB cable into the computer to power the board given that I have a delay statement before any code can execute? Specifically Q1, Q7 on the first multiplexer and Q1 on the second multiplexer? Given the code, all LEDs should be off when we begin?
12)   If you turn the power off to the Arduino Uno are any instructions left in memory that may run the next time you power the board?


Grumpy_Mike

#28
Dec 07, 2014, 09:45 am Last Edit: Dec 07, 2014, 10:13 am by Grumpy_Mike
Stop!
You have no resistors in line with those LEDs, you are killing stuff here.
Reading the thread again you have been repeatedly told this and you repeatedly ignore this.
Given that it is not worth answering your questions because it will be a waste of time because you are not in a mind set to learn anything.
Basically, testing for continuity on a built circuit tells you nothing useful.

Quote
The schematic for this is basically the shiftout example 2 minus the resistors. http://arduino.cc/en/tutorial/ShiftOut
No you are not doing that, there is no capacitor. Again you have been told about this and again you have ignored it. It is VITAL you give people a schematic of what you are doing, NOT something like you are doing.

I was trying to help but if you continue to ignore things you will never get anywhere with electronics.

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