Jump to content


  • Content Count

  • Joined

  • Last visited

Posts posted by audiodane

  1. USB-UART bridges (using RTS/CTS/DTR) are not fast enough for SBW, but they are OK for BSL. If this project have MSP430G2xx as target, than it can be small board with 2 QFN chips (USB-UART bridge and MSP430G2xx), with 3.3V supply form bridge reg. Firmware can be simply uploaded by BSL, and bridge can be used for UART comunication with PC (or logging). Of course, it must be used MSP430G2xx device that have BSL support (like MSP430G2553 for example).


    Other option is to put on board MSP430F550x for FET/bridge an also use internal 3.3V reg for MSP430G2xx target device. When MSP430F550x is not used as FET, it can be used for development too (USB BSL). It also can be only 2 QFN chips on board. Of course, for this option TI FET source must be adapted to MSP430F550x (or at least LP based BSL), while version with standard USB-UART bridge (FTDI/Prolific) don't request any coding and everything is prepared by TI. 

    Can you download and debug with BSL like you can with FET?  I don't really know the difference between the two terms.  I want debugging support..    I also need G2402 because it's already designed in.  Depending on cost, I could go with a different chip, but I'm trying to remain inexpensive.


    How does communication between the two MSP430's work if the FET has to run at 3.6V but the target has to run at 3.3V?  if the SWD wires are open collector and pulled up to 3.3V, is that sufficient for the 3.6V device?  Are SWD pins are open drain or push-pull?



  2. I want to have a USB-UART bridge for the CC430, and it is cheaper, better, and more interesting for the hacker to have it be an MSP430 than a FTDI chip.


    The thing is, USB-UART bridge firmware does not take a lot of space or resources.  So, I'm thinking what else I can put on there.  FET is certainly an option.  But since it is programmable, if you don't like the FET, you can reprogram the MSP to do something else.


    +1 to the above.  cheaper and more interesting (and more versatile) to have the usb-uart be an msp430 chip.  This is the approach I would like to take, but know not how to get the usb-bridge and fet support into this second msp430 chip.  That's what I'm looking for..   I specifically need to support a G2402 because it's already designed in.

  3. I don't really get your intent. If you are doing a custom PCB, why would you want to integrate an entire FET in it?

    The simplest way I know is to just add an eZ430 connector and use the eZ430 programmer/debugger as is. This does not meet your requirements for an integrated design, but I don't really see your point in doing that. In particular since you have a really small design, adding a USB socket/plug would greatly add to the size, which I suppose is not appreciated.

    So, what is your underlying intent and why would you need an embedded FET for that?


    That is an entirely fair question.  Simplest answer, too. :)  I have a tiny custom PCB to do a very specific task.  msp430g2402, a few leds, a few low-profile dip switches, and a 5-pin connector.  Plus (currently) an ez430 connector.  One specific feature that I would like to add is a debug/logging interface via serial-over-usb.  I can add that pretty easily, but given that the ez430 operates over USB, my question then becomes, if I embed a chip to handle a USB based UART that can also act as a SWD interface over USB, then I can sell the device to do my intended task, or I can sell it without loaded firmware as a tiny form factor hobby board. Currently I can add a SiLabs USB-UART bridge chip and connector, but it would seem so much more versatile if it embedded a programmer interface as well.


    My thought process is that it would be a little frustrating (and most likely lower sales volume) for hobbyists to buy a little board for USD$20-30 AND have to buy a programmer tool for another $25.  If I can embed the programmer interface and get the quantities up, the sales price wouldn't have to change, and they get a board that's simpler to interface with.  If I could sell even just 300 of these units over the course of a year, I can justify the added capital cost to produce the more complicated design.


    I currently have the entire backside of a 1/2" by 1" pcb empty (no traces or components) that I believe would hold the QFN and USB connector.  I could grow it slightly if necessary.


    However, my current understanding of the thread topic seems to indicate that while there is some real possibility, there is as of yet no "drop in solution" ready to go.  I am a bit pressured for time, so I may have to push this off until a second revision of the board.  I would very much like to see this happen but will have to rely on others because of the level of understanding required for the SWD interface and code as discussed above.  If such a tiny solution could be implemented, I would be more than happy to open source an EAGLE based schematic and layout of that circuitry (assuming someone else could add the firmware portion).




  4. Hi all.  Is there a proven, tiny, relatively simple circuit anywhere to embed SBW support into a tiny custom PCB?   I would like to remove the need for the FET adapter and connector if possible for this custom application.   I could rip off the schematics from TI's USB FET, but there are so many components in that solution and I'm trying to stay small, but also stay away from 0402 sized parts.  I have most of the back-side of a 1/2" by 1" custom MSP430G2402-based design available.  A bonus would be to double the interface as a serial-uart-over-USB bridge when SBW is not being used.  SMT components preferred.




  5. I was wondering if there is any pre-existing code out there for CCS v5 and an msp430f2102-ish type device?  I'd like to setup a tiny project that monitors an I2C bus and logs filtered transactions over UART..  Specific addresses or data values, for instance.  The uart terminal program then could timestamp the log data, so I don't really need to worry about that part.


    It's not ultra-critical, the data would just be useful to decypher in a side project I'm working on..  so honestly I am hoping that something like this already exists that I can just load-and-run and log the data.. post-process it later in Excel or something to extract out the meaningful data from the stream.




  • Create New...