Home > Electronics > FINALLY – the MSP430x2xx new serial module sucks! Finally got I2C working.

FINALLY – the MSP430x2xx new serial module sucks! Finally got I2C working.

October 20th, 2008

It took a solid 25+ hours of work, but I finally got the MSP430F2618 to talk to the AD5933 via I2C.  The TIs documentation sucks, their module sucks, and I’m angry.  But it works now.  A hit to those that might be stuck: The USCIABxTX_ISR() interrupt vector should be called the Master interrupt vector, and their USCIABxRX_ISR() interrupt vector should be the Slave interrupt vector.  In master mode, both the TX and RX interrupt enables results in the TX_ISR() vector being called.

Other issues include that the SDA line gets stuck latched low and will persist through a power cycle and a reprogramming.  You expicitley have to pull the line high in software to reset it.

A bunch of other issues later, I got it working..  I ended up picking up a new logic analyzer because of it’s improved interface than my USBee unit.  $150, and it ROCKS.  Joe makes them locally, and I recommend you pick one up for your toolbox.

data read from ad5933

data read from ad5933


  1. Basel
    | #1

    Dear Reza,
    I noticed that you know and work a lot with electronics, I need your help please, I noticed you have worked with the MSP430F2618.

    I am a new PhD student, my background is in mathematical communications (coding theory, multimedia compression, and channel fading modeling)
    I got a scholarship that pays my fees by a project, which I am a member in ( I know I am explaining a lot)

    our project is in wireless sensor networks. We have setup a remote sensor network, and we need to link this remote network by a satellite link. since i have no electronics background whatsoever, I started searching on how to build a base station, that takes the data from the sensor network and sends it via a satellite link. what i reached is I can use a Zigbee compatible RF transceiver combined with an ATMEL 128 or MSP430F2618 processor to control the data flow, the processor must be connected to the satellite link directly.
    I would like your expertise (if possible) in guiding my first steps, since I only started 2 weeks ago.

    yours truly,

  2. Evelyn Livermore
    | #2

    Dear Reza,

    I’ve been trying to use the AD5933 with the software I got when I purchased it. And I’m not really sure I understand correctly how the software works. I am able to get correct impedance readings if I calibrate it correctly, but the phase is still off. I was wondering if you had any experience with the software, or know of any other types of software that I can use with the AD5933.

    (I’m on my first day of my summer project, never done this before.)

    Evelyn Livermore

  3. admin
    | #3

    Do you have the eval kit for it? The software seemed to work fine for me, though I never validated the phase — I was only interested in magnitude variations corresponding to thoracic impedance changes from breathing. Otherwise, I just communicate via I2C from the MSP430.

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