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assembly/build guide for TC4 shield
bvwelch
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Posted on 03/03/2011 5:57 PM
I'm building a rev 3 version of the TC4 shield today, and thought I'd describe my approach. Please feel free to jump in with your input/experiences also.

In my view, the only 'difficult' part to solder is the ambient sensor -- it is in a SOT23-5 package which is rather small for me. But with some tweezers, and studying the surface-mount soldering tutorial on Sparkfun's web site, I've managed to get the job done.

But, I do this ambient sensor first -- that way, there are no other obstructions on the board to get in my way while I am huddled down with the head-mount magnifier and the strong desk lamp.

Then I do the rest of the surface mount devices. I save the thru-hole devices for last.

I got a little confused on the eeprom -- I couldn't quite tell where pin 1 was on the silkscreen, but hopefully I got it right. I plan to run the little eeprom diagnostic to make sure.

The rest of the surface mount parts went fine, and also the thru-hole caps, resistors, and transistors.

Next, I'll do all of the connectors and then I'll be ready to give it the smoke test -- after supper. -bill
 
bvwelch
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Posted on 03/03/2011 8:28 PM
Well, the connectors went fairly smoothly -- except the 90-degree connectors didn't seem to quite line up on 100mil grid? I was trying to use a single, long strip for the entire edge of the board, but once I broke it up into small sections it worked fine.

I wasn't sure which sketch to try first, so I tried aCatuai but didn't get too far. I switched and ran some of the eeprom tests and then ran the early ajlogger sketch which gave me a nice display of ambient and all 4 channels -- I used that to quickly convince myself that ambient and all 4 channels would at least respond to the halogen desk lamp.

The real test may come tomorrow or Saturday when I do some roasting.
 
bvwelch
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Posted on 03/03/2011 8:46 PM
Just for grins, I went back and ran Catuai and plugged in one of JimG's LCDapters - wow, very nice, buttons, leds, LCD, nifty modular jack. I love this concept.

OK, I need to do some roasting, and I also need to test the analog output and analog inputs but it looks like this TC4 is working fine!
 
bvwelch
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Posted on 03/03/2011 9:21 PM
Here are a few photos that may be helpful.

Arduino 'headers' come in two styles: "stackable", and "non-stackable". The "stackable" headers have long pins and a plastic in-line "sim" socket.

bvwelch.com/tc4/100_2140.jpg

The next photos shows examples of shields using both types of headers.

bvwelch.com/tc4/100_2136.jpg

Note these are the early version of the TC4 shields, but they illustrate the different headers.

Now, see below for the new shield that I soldered today -- a version 3 TC4 shield.

bvwelch.com/tc4/100_2141.jpg
Edited by bvwelch on 03/03/2011 9:23 PM
 
Unta
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Posted on 03/04/2011 12:36 AM
Bill,
Thanks for the play by play. I feel like this portion of the site has always been beyond me; but I'm feeling strangely close to this thread. I may be waking up the soldering gun and looking in to some new tools in the near future.
Thanks for starting from scratch, again.


Sean
Sean Harrington
educate.
 
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JimG
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Posted on 03/04/2011 7:34 AM

Quote

bvwelch wrote:
Well, the connectors went fairly smoothly -- except the 90-degree connectors didn't seem to quite line up on 100mil grid? I was trying to use a single, long strip for the entire edge of the board, but once I broke it up into small sections it worked fine.

I added a small gap between each pin pair for Ot1, Ot2, and I/O3. This is to accommodate the body of the 2-position Molex KK female connectors I typically use.

With the pins for these three channels all at 100, I could only use a 6-position connector; three 2-position connectors don't fit.

Glad to hear you were able to get it to work. smile

Is this something that should be changed in the future?

Jim
 
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bvwelch
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Posted on 03/04/2011 12:16 PM

Quote

JimG wrote:
I added a small gap between each pin pair for Ot1, Ot2, and I/O3. This is to accommodate the body of the 2-position Molex KK female connectors I typically use. With the pins for these three channels all at 100, I could only use a 6-position connector; three 2-position connectors don't fit.

Is this something that should be changed in the future?

Jim


Not at all, now that you've explained it, it makes perfect sense that real connectors/cables need a little extra room. Duh.

Great little board, thanks ! -bill
 
jsutton
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Posted on 03/04/2011 9:45 PM
Jim:
I received the last backordered capacitors from MOUSER today so the TC4 build should be complete.

How about describing the basic connectivity and testing of the just built TC4?

Do you attach thermocouples to the wire blocks, connect the USB cable, attach to a laptop, and something happens? Is there a way to test to know the TC4 is operating properly?

Thanks.
 
bvwelch
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Posted on 03/04/2011 10:49 PM
The first step is to get familiar with the Arduino and its IDE -- look at tutorials, buy a book, whichever you like. You don't need the TC4 shield installed for this -- there is an LED on the Arduino that you can blink, etc.

Then you might familiarize yourself with the various 'sketches' from the TC4 google code site. I like to do my initial testing with just the Arduino IDE -- since our TC4 sketches just send out lines of ASCII text to the serial port, you can just open the serial monitor in the Arduino IDE. Yesterday I found the aj_logger sketch to be really handy -- it is very short and you can look at it on the computer or print it out. It prints the ambient temp and the 4 TC values. I have a short scrap of K-type 'bead' TC wire and I just move it from channel to channel and observe.

There are some diagnostic sketches for the EEPROM also - again they just output to the serial port so that is easy to view from the Arduino IDE serial monitor.

Finally I'd suggest running the aBourbon sketch -- initially just with the Arduino IDE and serial monitor. If that seems to be working, then run the pBourbon sketch on your PC - shutdown the Arduino IDE first so there is no fighting over the serial port. Have fun! -bill
 
JimG
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Posted on 03/05/2011 12:03 AM

Quote

bvwelch wrote:
I got a little confused on the eeprom -- I couldn't quite tell where pin 1 was on the silkscreen, but hopefully I got it right. I plan to run the little eeprom diagnostic to make sure.


The silkscreen for that particular package in the Eagle library is pretty bad.

Pin 1 is in the "southeast" corner of the outline. There is a silkscreen line marking the side of the chip where pins 1 through 4 are located. But it is a little hard to see.

Jim
Edited by JimG on 03/05/2011 12:08 AM
 
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bvwelch
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Posted on 03/05/2011 7:17 AM

Quote

JimG wrote:

Pin 1 is in the "southeast" corner of the outline. There is a silkscreen line marking the side of the chip where pins 1 through 4 are located. But it is a little hard to see.

Jim


I noticed later that your photo shows the pin 1 location very clearly. I recommend that folks keep this photo handy when questions come up: http://code.googl...c4-shield/
 
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