JTAG Pin Spacing

An advanced Arduino-compatible board with ATmega1284P and ATmega32u2 MCUs for experienced users. More RAM than a Mega, but in a convenient Uno-style form factor. [Product page]
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ozra
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Joined: Tue Nov 05, 2013 1:24 am

JTAG Pin Spacing

Post by ozra » Thu Feb 06, 2014 1:03 am

Hi All,

Can anybody help me with the pin spacing for the JTAG connector?
Where can I buy such a header/socket?

Thanks, tried looking for a BOM but unfortunately could not find the specs for the JTAG connector.

Thanks

angusgr
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Re: JTAG Pin Spacing

Post by angusgr » Thu Feb 06, 2014 2:57 am

EDIT: This header is not correct, pitch is 2mm not 1.27mm. See two posts down for the correct one.

The spacing is 1.27mm (0.050", ie half the usual 2.54mm spacing.) The header footprint is for the Samtec FTSH-105-01-L-DV-K, which is a common JTAG SMD header style.

Here's a link to the Australian element14 source for those exact headers: http://au.element14.com/samtec/ftsh-105 ... -01-L-DV-K[/strikethrough]

ozra
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Joined: Tue Nov 05, 2013 1:24 am

Re: JTAG Pin Spacing

Post by ozra » Thu Feb 06, 2014 3:23 am

Thank You very much for your reply.

I'll have a look.

Regards

ozra
Posts: 4
Joined: Tue Nov 05, 2013 1:24 am

Re: JTAG Pin Spacing

Post by ozra » Mon Feb 17, 2014 5:48 am

angusgr wrote:The spacing is 1.27mm (0.050", ie half the usual 2.54mm spacing.) The header footprint is for the Samtec FTSH-105-01-L-DV-K, which is a common JTAG SMD header style.

Here's a link to the Australian element14 source for those exact headers: http://au.element14.com/samtec/ftsh-105 ... -01-L-DV-K

Are you sure?

According to the link you gave above, the pin spacing is 1.27mm

I have ordered the following SAMTEC - CLP-105-02-L-D - RECEPTACLE, 1.27MM, SMD, 10WAY
http://au.element14.com/jsp/search/prod ... KU=1667559.

As a matter of fact, a few from different manufacturers all 1.27mm spacing and they are all way too small.

If element14 shipped me one wrong item, I can understand it but all the ordered 1.27mm items are the same size but the Goldilocks connector measures almost 8mm in length connector 1 to 5 along the jtag axis. 4 hops: pin 1 to pin 5 x 1.27 = 5.08mm which is what I have received from element14.

Are you sure it is not 2mm spacing? I am trying to get the correct info so that I do not waste a further $60 on the incorrect parts.

What are the correct details for that connector?

Thank You

angusgr
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Re: JTAG Pin Spacing

Post by angusgr » Tue Feb 18, 2014 4:38 am

Hi ozra,

Argh, I'm so sorry! I did give you the wrong Samtec part number. The headers are 2mm pitch as you correctly point out.

(I was thinking of the 1.27mm pitch JTAG headers on a lot of ARM boards - including the Arduino Due and our forthcoming EtherDue - and got mixed up. Too many JTAG pinouts!)

Correct Samtech part number is TMM-105-01-G-D-SM. Here's the Samtec link:
http://www.samtec.com/technical-specifi ... Master=TMM

Here's the correct E14 link, unfortuantely it's out of stock: http://au.element14.com/samtec/tmm-105- ... samtec+TMM

Are you in Australia? If so, I have a used header that I can mail you. Drop me a line with your address, angus at freetronics dot com.

Otherwise, there are some 2mm 2x5 surface mount pin headers that look compatible, such as this Molex one. You'd need to check the footprints carefully to make sure the dimensions line up with the TMM though:
http://au.element14.com/molex/87759-105 ... dp/1686272

- Angus

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