Wiring TI Launchpad

[Crossle86]

Has anyone found a booster pack (extender board) or other cabling solution for the MSP430 Launchpad that is better than splitting ribbon cables? The previous board, Tiva/Stellaris had a booster board (BOOSTXL-IOBKOUT) that exposed the pinouts as screw terminals which is really what you would want for this type of board. While we can wire the MSP430 in several "manual" ways, its hard for me to believe there is no solution like the BOOSTXL for the MSP430. I am hoping such a solution exists and I just haven't found it. TI chat support did not have a solution...

[RaMoore]

Richard,

Sorry you weren't able to get better answers via our general support methods. TI is a huge company which supports a large number of customer requests every day, and unfortunately not everyone at TI is aware of our support of FIRST.

If you look on the application wiki (http://www.ti.com/robotics-FRClaunchpad) we have a special email list set-up to directly address questions from FRC teams: FRCSupport@list.ti.com. Please use this email for the most accurate and timely answers.

Regarding a screw terminal breakout board, while the silkscreen will not be correct, you can still use the BOOSTXL-IOBKOUT breakout board on the MSP430F5529 LaunchPad from your kit.

As one of the TI engineers which worked on this solution and a fellow FIRST mentor, I have some concerns about whether the screw terminals are really robust enough for the rigors of competition. I think it's a good solution for prototyping, but in the long term we want to ensure TI only provides battle tested hardware to teams. We are considering producing an updated breakout board for future years, but at this point the most robust and approachable solution we can suggest is the ribbon cable breakout.

[Cecil]

I too would love to see a breakout board of sorts. For the past 4 years, we used the Cypress board with this breakout. We had no problems with it, and they are still working today. For now, we have ordered ribbon cables and will probably make our own lexan enclosure, but some sort of breakout would be great to see happen!

[RaMoore]

Originally Posted by Cecil

I too would love to see a breakout board [...]

Thanks for the feedback! We are definitely going to see if we can get approval to make an FRC specific breakout for future seasons.

[Crossle86]

Rachel,
Thanks for quick and informative reply. It appeared to me that the BOOSTERXL should work but I could find no confirmation. Two follow up questions:

1) Given that the MSP and Boosterxl will be enclosed in the driver station, I'm not sure where your concerns about the robustness of the Boosterxl come from. It would seem to me the screw terminals would be adequate for DS application. Am I missing something?

2) Just to clarify, when you say ribbon cable "breakout", do you mean manually separating the conductors of the cable or is there some other way to do that?

[RaMoore]

Richard,

Originally Posted by Crossle86

1) Given that the MSP and Boosterxl will be enclosed in the driver station, I'm not sure where your concerns about the robustness of the Boosterxl come from. It would seem to me the screw terminals would be adequate for DS application. Am I missing something?

If properly strain relieved and everything is secured in the driver station, the screw terminal are probably fine.

However not all teams are nearly so careful with their wring and screw terminals are terrible under strain and then you add in all the vibration from being carried on bumpy cart rides, tossed around, knocked off the driver station shelf, picked up by wires, etc... these can all cause screws to start to loosen. Same reason why the mechanical guys use the lock nuts or thread lock. These loose screws can cause a wire to come out, or worse, an intermittent contact issue.

We had considered trying to push through a new breakout for this year, but we were just too resource limited to do a great job since most of the development for this project is done on top of our normal day jobs. Rest assured, a new breakout is very high on the list for next season's projects.

Originally Posted by Crossle86

2) Just to clarify, when you say ribbon cable "breakout", do you mean manually separating the conductors of the cable or is there some other way to do that?

You're correct, just separating the conductors for the ribbon cables. Once the LaunchPad is mounted down, the ribbon cables make a good solid connection to the board headers and the color coded wires make wire tracing easier. Our team found it pretty easy to then solder these wires directly to panel mounted buttons.

Since it's a standard .1 pitch header, someone also probably makes a PCB breakout you can attach to as well, but since you can just directly use the BOOSTXL-IOBKOUT it's probably not advantage to look for one--just mind the silkscreen won't match.

[dyanoshak]

Originally Posted by RaMoore

Regarding a screw terminal breakout board, while the silkscreen will not be correct, you can still use the BOOSTXL-IOBKOUT breakout board on the MSP430F5529 LaunchPad from your kit.

As one of the TI engineers which worked on this solution and a fellow FIRST mentor, I have some concerns about whether the screw terminals are really robust enough for the rigors of competition.

Section 2.3 Standard BoosterPack Pinout Compatibility in the BOOSTXL-IOBKOUT User's Manual talks about what you should look at when connecting the BOOSTXL-IOBKOUT to a non-Tiva Launchpad.

Specifically the analog signals pass through unity-gain amplifiers before going to the launchpad.

I designed the BOOSTXL-IOBKOUT with both screw terminals and 3-pin PWM-style headers. The headers are a more robust option that uses a cable/connector commonly used in FRC.

The breakout also has ESD protection on all of the headers/terminals. This doesn't protect from a static zap to the launchpad itself, but zaps to connected circuitry (buttons, switches, etc.) shouldn't be a problem.

I don't imagine the BOOSTXL-IOBKOUT is a long-term solution. The Stellaris/Tiva group at TI no longer exists. Therefore:

Originally Posted by RaMoore

We are considering producing an updated breakout board for future years

Keep bugging TI and Rachel to create another breakout!

-David

[Crossle86]

Finally getting back to this issue. I'm wondering about the statement in the last post that indicated the boostxl-iobkout board has pwm style 3 pin headers. There are no headers on the boostxl I have, only screw terminals.

[dyanoshak]

Originally Posted by Crossle86

Finally getting back to this issue. I'm wondering about the statement in the last post that indicated the boostxl-iobkout board has pwm style 3 pin headers. There are no headers on the boostxl I have, only screw terminals.

The way I worded that was a little misleading. The headers need to be added by the user. Standard 0.1" pitch breakaway headers will work. You can usually find these at your local electronics store or Radio Shack (if it hasn't closed down yet). You can also find them anywhere components are sold online like Digikey. It would be a great use of the DigiKey voucher that came in the kit this year.

• Breakaway Headers
• DigiKey Voucher: www.digikey.com/first

[Crossle86]

I'm sure I being dense here, but how do you use these headers to make one pin on the launchpad (I assume you are talking about doing the pad itself as the booster would be unnecessary if you can wire to the pad) into a 3 pin connection. Do you break off 3 pins but just put one pin in the socket on the launchpad?

[dyanoshak]

Originally Posted by Crossle86

I'm sure I being dense here, but how do you use these headers to make one pin on the launchpad (I assume you are talking about doing the pad itself as the booster would be unnecessary if you can wire to the pad) into a 3 pin connection. Do you break off 3 pins but just put one pin in the socket on the launchpad?

You break off rows of headers and solder them to the pads that are directly behind the screw terminals. They are labeled the same as the screw terminals and are in the standard 3-pin arrangement: Signal-Power-Ground (S + -).

Take a look at the attached picture.

[Crossle86]

Picture is worth 1k words! Thanks so much.