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msp430- coding interrupts for mspgcc

3
Posted by Justin on September 2, 2010 – 6:13 am
Filed under electronics, Hardware, MSP430, programing, software
Tagged as , , , , , ,

I am just an idiot, but thats my opinion. For those with MSPGCC compilers, we have a more difficult time finding code examples, and many of the code examples given either don’ explain very well (cryptic Coding, un-commented code) or they are for the CCS or IAR, and they dont use the same syntax as the MSPGCC compiler. So here is how to create an interrupt handler for non-PUC/POR interrupts.

I will not go into interrupt vector masking, that is beyond me at this moment, but im not saying that i wont cover it later on, once i understand why you would want to mask it…..
So lets start at what headers and other setup items you need before, creating the interrupt handler.
First the signal.h has to be included into your code. #include<signal.h>
this will give you access to the special function of
interrupt(VECTOR ) service_routine (void) {/*interrupt code*/ }

this is the same as #pragma vector=WDT_VECTOR
__interrupt void watchdog_timer(void){ }

These are the Defined vectors for interrupts right from the header files.(mspgcc headers)

#define PORT1_VECTOR 4 /* 0xFFE4 Port 1 */
#define PORT2_VECTOR 6 /* 0xFFE6 Port 2 */
#define USI_VECTOR 8 /* 0xFFE8 USI */
#define ADC10_VECTOR 10 /* 0xFFEA ADC10 */
#define TIMERA1_VECTOR 16 /* 0xFFF0 Timer A CC1-2, TA */
#define TIMERA0_VECTOR 18 /* 0xFFF2 Timer A CC0 */
#define WDT_VECTOR 20 /* 0xFFF4 Watchdog Timer */
#define NMI_VECTOR 28 /* 0xFFFC Non-maskable */

all the interrupts should be self expainatory, vector = the source of the interrupt.

since now we have all the basics we can now right a small program that uses interrupt, we will just create a small WDT interval timer.
/*WDT interval timer- code based on msp430 examples*/
//compiler=mspgcc
#include<msp430x22x2.h>
#include<signal.h> //interrupt service routine
#include <io.h> //usually included on msp430 header, but for sfr register access.
void main(void) {
WDTCTL = WDT_MDLY_32; //~30mS intervals
P1DIR |=BIT1;
IE1 |= WDTIE; //enable interrupt
_BIS_SR(LPM0_bits + GIE); //not low power mode and enable interrupts
}//end of main
//interrupt service routine
interrupt(WDT_VECTOR) watchdog_timer(void)
{
P1OUT ^= BIT1;
}//end of interrupt

this should give you a good start on your Interrupts but there is still one thing that you may need. Changing the power modes when a interrupt is being serviced, the power mode will revert back to the power mode that it was in when the interrupt was called.
There are 2 functions that we can use to clear or set power modes while in an interrupt.
First one is to set the mode on exit of the routine, this is done by changing the copy of the status register that is saved to the stack. _BIS_SR_IRQ( ... )
you would use this the same way you would use the _BIS_SR(…)

The second one will clear the bits you select _BIC_SR_IRQ(...) same usage as the other, except it will just clear the bits not modify them.
***the use of _BIx_SR_IRQ() should only be used in an interrupt service request, the compiler will give you a warning but will produce the correct code if you use it anywhere else.***
****remember to enable Interrupts by using BIS_SR(GIE) or eint()****

Edit 6-23-2011

MSPGCC Uniarch branch of mspgcc has been released, It supports newer chips like the msp430G2453 (the newer 20pin DIPs) This is an initiative to unify the current branches of mspgcc. Interrupts for this version is slightly different. Once I test it or get confirmation from another user I will post the correct format for uniarch branch……but what would be better would be unify the branches so we don’t have so much confusion with these version discrepancies and nuances of the trees.

As of right now uniarch is still being worked on and there and is not fully recommended unless you need support for the newer 20pin Dips (G2x53 G2x52).  Please don’t let my opinion dissuade your choice of compiler, mspgcc works great for me but uniarch may work better for you.

 

Thank you Tissit for your Comment

“In current gcc, you can (should) include msp430.c instead of the specific header and use the -m switches (in a Makefile) to tell the compiler which chip you’re using. It will find the right headers automatically. “

If I forget something let me know and I will update

IR eye

0
Posted by Justin on November 13, 2009 – 8:02 am
Filed under arduino, electronics, Hardware
Tagged as , , , ,

This project is the first step in my motion tracking. This Eye was built and adapted from an LRM post here .

DSCN0219DSCN0221please dont laugh at my soldering job, its what i can manage with that kind of board, I like the ones that mimic a breadboard setup. With very little trouble i finished soldering in about 2 hours but had to go back a desolder one transistor and replace it and resolder one wire. After that i tested each IR sensor by themselves to make sure they all worked, each one gave a little different reading off the same IR source but that can be fixed with a little calibration in the software. But for now my goal is to hook it up to 2 servos and control the x and y for the motion tracking, eventually i would like to put this into an enclosure that looks like an eye.
This is to make sure all 4 eyes are working
const int sensepin0 = 0;
const int sensepin1 = 1;
const int sensepin2 = 2;
const int sensepin3 = 3;
int sensorValue0 = 0;
int sensorValue1 = 0;
int sensorValue2 = 0;
int sensorValue3 = 0;
void setup() {
Serial.begin(9600);
}
void loop() {
sensorValue0 = analogRead(sensepin0);
sensorValue1 = analogRead(sensepin1);
sensorValue2 = analogRead(sensepin2);
sensorValue3 = analogRead(sensepin3);
Serial.print("sensor = ");
Serial.print(sensorValue0);
Serial.print(" ");
Serial.print(sensorValue1);
Serial.print(" ");
Serial.print(sensorValue2);
Serial.print(" ");
Serial.println(sensorValue3);
delay(10);
}

this will test all 4 sensors and print to the serial port.

also this code is written for the arduino but can be adapted to other microprossecors.

Here is a screenshot of the schematic as well

ScreenshotNext i will mount it to the servo and start writing the logic for 1 of the axis, but my question is how to mount this to a servo with stuff wround the garage. I will answer this question soo.

and this is why you should never place you MC on your keyboard…………..Screenshot-1that large stack to the left is about 30 print screen applications running. I placed my arduino on my print screen button for about 10 secs before I realized what was going on.

Parts:

  • 4x 2n 2222 NPN transistors (generic NPN)
  • 4x 220 Ohm 1/4w resistors
  • 4x NPN photo transistors
  • a bunch of wire
  • Arduino

I hate slow DBs

0
Posted by Justin on November 10, 2009 – 10:28 am
Filed under General, software
Tagged as , ,

Have you ever called a place that needs to look up your account or other info? ever notice how it takes about a some time for them to get that info?

I’m the guy on the other side of the line waiting to get that info so I can help fix what ever problem they had called in with, and the longer i work the more i notice that its taking longer and longer to for me to pull up any info about any account. So whats is the deal, why cant a multi billion dollar company fix a database?

We live in the Age of Information, where almost everything is instant, where people expect info or help to be provided to them that instant. My guess is everyone at my place of employment probably don’t even notice the long waits between DB queries through our ticketing system. So how long is long? well i decided to test this, for a basic customer id I queried takes about 20 seconds, ok thats acceptable but thats only to bring up there info, not there ticket history. So i click on there history, guess what another 30 seconds on the clock, so it starting to get bad, after that you can click on individual tickets, create a new one or use tabs to look at more info. Each tab when clicked on takes 5-25 seconds to open. And these are the fast times, other times i sit 30 secs to about 1 min to get anything useful, and there have been times that I started a query when I left for break , came back and still had 5 mins to wait till it finally showed some results. My querries where presise and dont pull alot of data, but this is getting ridicolous. So how does a database get this slow? traffic? Nope cant be traffic, I work 3 rd shift and have about 15 people who use it , during the day over 100 people use it. What about maitnence? not likely, thats run once a week for about 2 hours or so.

What else could it be? corrupted database? bad design for a large database? I  have never worked with a large database like that before so I don’t know the challenges of design or maintenance of such a large beast. But I have worked with smaller DBs that had similar slowdowns, but that was caused by too much data being pulled, like querying the entire DB or a few thousand rows. Or could the bandit be the vendor lock on the ticketing system in combo there DB, by the way the ticketing system looks very customized and even has features, custom built by other vendors, like the data being pulled from  an access database or integration into 2 other ticketing systems. My guess is Oracles Seibel, and DB work wonders out of the box and setup correctly even better when you use there system to input the data. I wonder who approved adding more plugins was a great idea?  This kind of bloat is inexcusable in a place where employees are timed. How do you fix something thats going to get screwed anyways, there policy just keep it chugging along, my solution would be to start gettting rid of or migrating 3yr+ old tickets and closed accounts to another DB, at least it would be a start, next would be to start removing the bloat from system, we do not need it to make our coffee and tell us were great. We need something light fast and simple, all we want to do is get the person what they want and move on. What will it take for these so called decision makers to realize that there all in one application dream doesn’t work in reality. Maybe this will become the next epic IT failure? not likely because its behind closed doors and if it failed i doubt that they would even tell the employees. So far i enjoy working for the smaller company, at least your voice is heard unlike here where your the bottom of the barrel.

Sorry about the long rant but some things at large companies are inexcusable that can throw money at situations. I thought customer service was supposed to be the focus of what we do. When will the people who call the shots going to learn to think logical instead of  using a magic 8 ball and some business lingo to make decisions about technology.

Hacking the Code

4
Posted by Justin on October 4, 2009 – 9:47 am
Filed under PHP, security, software
Tagged as , , , , , ,

Last Post i was talking about how to clean up a hacked web server, hopeful your server is clean now and you can get back to what you do best. But what was the hacker trying to do? What does that long string mean? I will tell you how to decode the string the safe way, and understand how it was constructed.

The Example that I am going to use is from a real hacked website, the code that I will display is only partial but the construct will be complete. Any identifiable URLs will be changed to prevent identification and your safety.
Lets start by identifying the code, this is what i had found at the very beginning of the page.
<? /**/eval(base64_decode(aWYoZnVuY3Rpb25<–>KTt9fX0=)); ?>

lets start with /**/, it looks innocent but its a way to hide the code, what the code usually used for is large blocks of comments instead of using // on each line you would start it with /* and  end with */ but what i noticed is that in bluefish and notepad++ when these are highlighted the whole line appears to be a comment, my guess is that other code scanners will look like one long comment  on that line and skip it. But this is just my conclusion and testing, very clever way to use comments.

almost forgot the first thing to notice is the use of short tags(<?) that they use, on my personal server I have short tags disabled, I had learned that it should be disabled for security purposes, I don’t know if this holds true today. but the reason they use it is it helps hide it as a comment adding php to   it (<?php),makes it show up as php code not a comment, now its starting to unravel………

eval — Evaluate a string as PHP code

very simple right, they need something to run there code, eval does this trick, you can even add html to the string. just another peice of the pie.

base64_decode – it decodes base64 code, now what is base64? It was originally for email to send binary data in emails, and other uses like binary data in urls and other variables but newest use is hiding php code in a long string, the string was 2692 characters long. So what did that string have in it.

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Web Site Security- what to do when you get hacked?

0
Posted by Justin on September 30, 2009 – 4:31 am
Filed under General, PHP, security, software
Tagged as , , , , , ,

Recently a Client/friend asked me to help him with his site after he found out he was hacked, in a situation like that i would gladly volunteer my time to help assess and fix the issue and prevent it from happening again. All the Guides from the major CMSs or other frameworks all have help guides to helped you when you get hacked. WordPress and Zen cart both have very good guides, but this guide should be a general help guide to getting back on track, you may have better site specific info from the company that developed the framework. Also check the forums as well for other people that have been hacked and how they fixed it and what the cause was.

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