Σάββατο, 23 Μαΐου 2015

Programming Target and Breakout Boards using a Launchpad

Using the launchpad as a spy bi-wire programmer is not new: People have been doing it with the value line launchpads for ages. But how about using a launchpad to program a chip in LQFP-64, LQFP-80 or LQFP-100 package (or in other SMT style packages). These chips cannot be directly breadboarded but compared to the THT MSPs, they are a lot more powerful, hence a lot more desirable :)

As I found out, there is more than one way to use your trusty launchpad to program these.

The Target Board

Texas Instruments sells boards equipped with ZIF (Zero Insertion Force) sockets for just about every package type they produce an MSP in. The boards alone sell for about 80-100 USD officially, but you can get much better prices on ebay. The target board will allow you to insert your MSP, connect it to a JTAG programmer (sold separately), program it and then remove it and use it in your PCB or prototype board.
Guess what: you don't really need to buy the JTAG programmer (FET interface), since you already have the launchpad!
I recently acquired an LQFP-100 target board (MSP-TS430PZ100B) and a couple of MSP430F6736 and set out to find how to program them using the F5529 launchpad.  It turned out to be pretty easy:


Launchpad to Target board

The connections are straightforward:

Launchpad to target board schematic
Your launchpad will program and also power the chip in the target board. Don't forget to set your target board configuration to Spy bi-wire. There is usually a set of jumpers that you have to move to the SBW position:


While a target board is handy, it will only allow you to program specific types of chips (unless you start collecting target boards, which might become a rather expensive hobby). But there is another way to program MSPs and use them for prototyping too: the breakout boards.

Programming a Breakout Board

Fortunately, eBay is full of sellers for breakout boards of any type. I ordered ten LQFP-100 boards from a seller in China. These were promptly delivered and I soldered a couple of F6736 chips on them:


After soldering some headers on it, I set out to find the minimum circuit that would allow this little board to work and get programmed by my launchpad. It basically comes down to this:


You will have to look at the datasheet for your specific MSP to find out which pins to connect and where. There will be more than a couple of pins that need to be tied to Vcc and GND and also a few that will require capacitors to GND. The spy bi-wire interface needs a few additional components (you can probably ommit the 330 Ohms resistor though). And this is how it looks like:

Launchpad to breakout board

Yes, it's a big mess of wires. But it works!
And of course if you are designing your own PCB, you can just provide a port for the spy bi-wire pins and program your MSP directly in circuit. Either way, MSP programming is a lot of fun!

Δεν υπάρχουν σχόλια:

Δημοσίευση σχολίου