Markers

Hi, I have built an embedded product on a custom pcb that uses an MSP430G2553 communicating with a MMA8451 accellerometer via I2C, and flashing LEDs when certain acceleration events cause interrupts. The system works reasonably well but I want to add some post-interrupt code to verify the direction and intensity of the acceleration to avoid false positives. I can read the value in the relevant TRANSIENT_SRC register (0x1E) on the MMA8451 but the system hangs returning from the ISR. I placed a breakpoint in the closing curly bracket of the ISR, and when I stepped past this breakpoin

Hi Jcjc, If your follow the response stream above you will see that I had to rename my User file to remove a space I had in my name. It was a bit of a pain but eventually it worked. Regards, Mark

Hi Zeke, Yes, that is exactly what I have done, and the end result is exactly what I needed. Thanks again for your help. Cheers, Mark

Hi again Zeke, I have found either a workaround or the correct solution (not sure which!): I addded "_bic_SR_register_on_exit(LPM3_bits);" to the end of both ISRs which I have never had to do before, but it is all working perfectly now. I'm very grateful for your help. Regards, Mark

Hi Zeke, I have implemented your suggestions for Fired and Serviced flags outside of the ISRs but now the program will not fall into the while(1); loop at all after an interrupt. I know the program loops through the ISRs at the appropriate times but nothing else happens. Do you have any idea why this is happening? Thanks, Mark

Hi Zeke, Many thanks for your prompt response. Yes, indeed it does help! I was concerned about all the activity in the ISRs but wasn't sure how to extract it. The printfs will certainly be removed once the prototype is stable, and I will tune the ACLK so that I get a consistent 1 minute loop. Finally, I have found the cause of the occasional error in the Timer ISR: if the process freezes for more that 1 minute (1 cycle) another Timer interrupt is created causing the program to run through the ISR and increment ++TThis. I will disable this spurious interrupt which should fix my

Hi all. I have made a lot of progress on my project, and have only one issue eluding me at this stage of the prototyping It involves getting a timer interrupt and a button interrupt to work together. I have 3 key times T1, T2 and T3 that determine the actions: between time 0 and T1 nothing happens; between T1 and T2 the timer re-sets to zero and starts again; between T2 and T3, P1.6 flashes 10 times; and after T3 the timer must freeze where it is until a button interrupt re-sets the timer to zero and starts again. The code is attached. You will see I have implemented tiny_printf so

Hi NurseBob. Thanks for your latest messages. The reference on low power design is great and will certainly help. You are correct in your assessment that l am "just getting into electronics" : I am 70 and a recently retired engineer and loving getting into hardware after decades of (self-taught) programming. Hence the sometimes naive questions! I have been using Dave Jones' blog which is very informative. Thanks again.

Hi All, I think I have discovered something, but I'm not sure what! I noticed when I turned my LED desk lamp off the consumption rose, and fell again to it's ~12uA level when I turned it back on. Also, the LaunchPad was on my desk quite close to my laptop. I then dangled the LaunchPad over the edge of the desk on the USB cable (ie. in the shadow of the lamp, and below the level of the laptop), and the power consumption went down to a steady 0.6uA as in the Workshop video! The power consumption still shoots up if I move my hand close to the LaunchPad... Thanks for all your hel

Hi Frida, Thanks - those are good thoughts. The Lab example has the following code which I assumed handles the inputs and outputs: void ConfigPins(void) { P1DIR = ~BIT3; // P1.3 input, others output P1OUT = 0; // clear output pins P2SEL = ~(BIT6 + BIT7); // P2.6 and 7 GPIO P2DIR |= BIT6 + BIT7; // P2.6 and 7 outputs P2OUT = 0; // clear output pins } Would that code not be sufficient to prevent noise from any un-t

Hi Rei and NurseBob, Thanks for your responses. Rei, yes the green LED jumper is on, and no, the green LED pin is not shared - as per the Workshop video, the LaunchPad is stand-alone, only connected via the USB cable to the computer. NurseBob, I have tested the project in Release mode and the power consumption drops to about 10-17uA, but the reading fluctuates a fair amount. Interestingly, if I hover my hand over the top of the LaunchPad the power consumption goes up to 60-80uA but again very variable!? The vidoeo in the Workshop does not show such fluctuations, and I can't un

Hi, I have been working through the MSP430G2553 Workshop and have just finished Lab 6. Running the code from Lab6c.txt in the supporting files does not give me quite the same results as in the video: the green LED does not come on, and the current draw on my Digitor Q1585 DMM shows about 20uA, not the 0.6uA I was expecting. Does anyone know whether my LaunchPads may be faulty (I have tried the example on 2 with the same results) or whether my DMM does not have a sufficiently low effective resistance? I am reluctant to continue with the Workshop until I am sure I will be able to

Hi All, Many thanks for all your responses. NurseBob, you were right on the money: Energia was not installed. I re-installed it and everything is now working as it should. Many thanks! Mark

Hi, I was working on an imported Energia project in CCS when I was informed that a software update to CCS was available. I installed the upgrade and restarted CCS in my project which now will not build. Instead I get the message "Buildfile generation error occurred.. Product 'energia.core' v18.0 is not currently installed and no compatible version is available. Please install this product or a compatible version. Build stopped.." My version of Energia is the latest (18). Can anyone help please! Thanks, Mark

Thanks Rei. Wish I had known before I wasted money on three 2553s.