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6pin connector for SpyBiWire+Serial?


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Hi all

 

I am looking to develop a small, bread-boardable (and altoids-embeddable) development board for the msp430g2xxx-series a la the arduino pro/micro/nano.

 

My first prototype was a total botch-job, with everything in the wrong place, as well as an unstable crystal (layout and capacitance-issues, I think). Se bad photo below.

 

My second protype is on the way, but it still has a 4-pin SBW-interface with VCC, GND, TDIO(reset) and TCK(test). Although I do not usually use serial, I have decided that it would probably be a good idea to add. I have searched for a standard pin layout, and have discovered that there is none.

 

But I wanted to ask if there was some sort of almost-standard for a 6 pin SBW+serial interface?

 

And I am completely open to ideas for improving the design :-)

post-33842-0-01636100-1389375321_thumb.jpg

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Here's some more details on that (not typing from my phone anymore lol)-

 

http://processors.wiki.ti.com/index.php/Category:EZ430_Development_Tools

In particular, this tool shows the 6-pin variant of the connector in use: http://processors.wiki.ti.com/index.php/EZ430-RF2500

 

Note that the MSP430 LaunchPad (G2-series, i.e. older one going for $9.99 these days) has an unpopulated header for this connector.  Requires a 1x6 right-angle 50mil male header, then your project will need a 1x6 50mil female header to plug into that.  However on the MSP430 LaunchPad, the UART pins were reversed.  This was done so that eZ430 targets could be plugged in and talk back and forth to the MSP430 G-series chip on the LaunchPad, not to talk back to the PC.  Since this connects to the bottom-side of the MSP430 LaunchPad, you could flip-flop those UART connections using the TXD/RXD jumpers so they talk correctly to the PC.

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My second protype is on the way, but it still has a 4-pin SBW-interface with VCC, GND, TDIO(reset) and TCK(test). Although I do not usually use serial, I have decided that it would probably be a good idea to add. I have searched for a standard pin layout, and have discovered that there is none.

 

But I wanted to ask if there was some sort of almost-standard for a 6 pin SBW+serial interface?

 

Question is related to my SBW+ interface or what? OK, It is clear, just joking. :smile:

 

Here you can see my DIY P2P boards... http://forum.43oh.com/topic/2972-sbw-msp430f550x-based-programmer/?p=42850

 

On the boards that I don't need any pins/connection, or that will not be used in future as base for development, I just leave conection to VCC, GND, TEST and RESET pins, and RX/TX UART lines, standard male headers. For example on 2 boards with MSP430F5435, there are 5-pin SBW+ connector, and two 2-pins UARTS (RX0/TX0, RX1/TX1).

 

DIP is DIY friendly, so you can put 2 male headers near chip body (only few millimeters wider board), but even without this you have access to all pins (simply by touching pins on chip body, or plugging tin wire into socket near pins)

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Yup for small simple stuff that is good. There is also the 2.54mm 14-pin FET430 pinout, used by TI's professional JTAG products for the MSP430, but it's wasteful on space and has no UART support. There is also a TagConnect pinout that takes very little space, but it requires a special adapter to the FET430 and also doesn't support UART signals. So the eZ430 pinout is the most straightforward to approach this. Might be worth designing a simple adapter board to break out the LaunchPad's emulator and UART pins to your connector so you don't need to fumble with jumper wires :D

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interesting. I did not know there is a preferred spy-bi-wire + uart pinout. but I am wondering why they elected to provide what seems to me the worst ordering for the power pins:

1. TX
2. GND
3. RST
4. TEST
5. VCC
6. RX

basically if someone plugs the programmer in reverse it's POOF time. and not only for the uC, but to all ICs that share Vcc on the target board.

so if someone uses this pinout in their designs with un-keyed pin headers they will have to be careful.

 

and to be slightly more on topic, I like the molex 0530470610 (1.25mm picoblade) type connectors for this use case. they don't come cheap but they do look great :rolleyes:

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interesting. I did not know there is a preferred spy-bi-wire + uart pinout. but I am wondering why they elected to provide what seems to me the worst ordering for the power pins:

1. TX
2. GND
3. RST
4. TEST
5. VCC
6. RX
basically if someone plugs the programmer in reverse it's POOF time. and not only for the uC, but to all ICs that share Vcc on the target board.

so if someone uses this pinout in their designs with un-keyed pin headers they will have to be careful.

 

and to be slightly more on topic, I like the molex 0530470610 (1.25mm picoblade) type connectors for this use case. they don't come cheap but they do look great :rolleyes:

Yeah, that wasn't a smart layout to be sure.

 

Sent from my Galaxy Note II with Tapatalk 4

 

 

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Yup for small simple stuff that is good. There is also the 2.54mm 14-pin FET430 pinout, used by TI's professional JTAG products for the MSP430, but it's wasteful on space and has no UART support. There is also a TagConnect pinout that takes very little space, but it requires a special adapter to the FET430 and also doesn't support UART signals. So the eZ430 pinout is the most straightforward to approach this. Might be worth designing a simple adapter board to break out the LaunchPad's emulator and UART pins to your connector so you don't need to fumble with jumper wires :D

 

I used tag-connect for the PIC projects I've done in the past and I really like them.  The pic connector is 6 pin, so all you need to do is make up a simple adaptor with the .05" ez430 header on one side and an rj45 for the tag connect cable on the other.  A while back I drew up a set of boards to do just this, as well as adapt .05" to .1" and adapt the ez430 format to a similar format that lacks mirror symmetry (otherwise it is easy to reverse the polarity).  I've been meaning to get them printed up and built, just haven't done it yet.

 

Also... here are some female-female, 6 conductor cables in both .1" and .05" pitch:

http://www.digikey.com/product-search/en?pv31=241&pv88=7&pv89=2&pv89=1&FV=fff40018%2Cfff80232&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

 

 

The one downside to the Tag-connect footprint I found is that if you use the footprint (and cables) with the locking holes, you have to use 6mil traces to access the pads.  This is smaller than most of the budget fab houses will accept.  The alternative is to get the cable without the locks, but that makes debugging a PITA, as you have to hold the cable in place the whole time.

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