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1  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: Hardware robustness... (ADC & RESET)... on: November 29, 2010, 11:16:36 am
Thanks PaulNoel for you comments. I have put all the components in to a metal box from a VGA extender, except of coarse the sensors. The sensors connected via shielded cable and are no longer than 0.5 meter. It also runs of the battery, which is in the box iteself and the power line has ferrite ring as you can see on the picture.
The battery is good to hold for many hours and I doubt that its voltage drops below the minimum "browning out" voltage. But that is quite difficult to know.
At my last racing on the track the logger failed miserably, resetting at the rate of 4-5 resets per minute, more at the faster parts of the track.
Now I have made another mod in addition to the ones above. I have cut the PCB line going from PIN 1 of the ATMega see picture to avoid this line acting as an antenna.

This mod will make me loose automatic reset during uploading sketches, but I am OK with the manual reset, just time the button press right after the upload begins. smiley-wink
I am going to test it next weekend and let you know the results.
2  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: Hardware robustness... (ADC & RESET)... on: October 28, 2010, 06:25:12 pm
I will be testing this solution this weekend. Will keep you posted.
3  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: Hardware robustness... (ADC & RESET)... on: October 22, 2010, 05:31:44 am
I did connect LED with 5000ms delay in the setup() and it comes on everytime I rev the engine high.
Now, I am connecting the pull up resistor and capacitor as  recommended in diagram below.
The R value is 4k7 , capacitior C 0.1u and 1N4148 diode.
on Page 15. Sorry can't upload the picture itself.
4  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: Hardware robustness... (ADC & RESET)... on: October 19, 2010, 05:45:27 pm
Thanks guys for hints in solving this puzzle.  smiley-wink
The ignition is part of the engine, which is at the back of the go-kart and my logger is at the front, sitting behind nassau panel, but i guess the EMI from the ignition is still quite strong there. I am certain it is the ignition noise causing the reset, as the logger would run for hours until engine starts. How do I know it had been reset? it would create a new file on SD card less then second after it stoped writing to last file. The timestamps from the GPS show that.
I wouldn't change FUSE to disable RESET it is still useful feature. After I have studied AVR40 & AVR42 I understand better how to implement EMI protection. I have had a close look at the PCB itself and the Pin 1 (reset) on the chip wired all over the place! :o and its connected to a pin on ISP connector sticking out like an aerial! No wonder it will pick up EMI very well. So idea for now is to cut the ISP pin 1 and place a diode to Vcc and 0.1u capacitor to the ground, as close as possible to the Atmel 328 pin 1.
Regarding the RX biased on twentyten. Well I have GPS output wired to RX pin, so on restart of Atmega, gps would still be sending data to RX pin. Would that cause it to freeze? I think I had couple of times when something like that happened.
5  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: Hardware robustness... (ADC & RESET)... on: October 17, 2010, 04:34:22 pm
This is it guys.    :o I think I have found an answer. I am using Atmega 328P in a race data logger installed on a go-kart, due to the kart size it can not be moved far from an engine. I am having problem with constant Arduino resets (see here
My three inputs which connected to sensors external to the box a already have low-pass filters, but resets still occur.
After reading this topic, I am suspecting the RESET pin to be cause of this, so EMI resets the processor via reset pin.
I didn't quite understand the point 2 of the first post, how to protect the reset pin from EMI? Would directly connecting the reset pin to Vcc help?

Secondly, is there way to completely disable the reset function?
6  Forum 2005-2010 (read only) / Interfacing / Re: Simple GPS logging to SD with Duemilanove 368 on: September 01, 2010, 03:50:13 pm
Hi PaulS! thanks for reply. This code above I used only just to test the GPS. The setup as follows: The GPS TX wire connected to PIN 0 on Arduino board. Also GPS's GND and 3.3V connected to Arduino board as well. I connected PC to the USB port for monitoring data coming from the GPS, using Arduino 0018 serial monitor.
The code above just sends to PC everything it receives from PIN0. My understanding is PIN 0&1 and USB Serial FTDI is the same thing.

I have just realised, I haven't included the code for writing GPS data to the SD card in the post above, here it is.
/* Code starts here - call it GPSLogger_v2.1 :) */

// this is a generic logger that does checksum testing so the data written should be always good
// Assumes a sirf III chipset logger attached to pin 0 and 1

#include "AF_SDLog.h"
#include "util.h"
#include <avr/pgmspace.h>
#include <avr/sleep.h>

// power saving modes
#define SLEEPDELAY 0
#define TURNOFFGPS 0

AF_SDLog card;
File f;

#define led1Pin 4
#define led2Pin 3
#define powerPin 5

#define BUFFSIZE 75
char buffer[BUFFSIZE];
uint8_t bufferidx = 0;
uint8_t fix = 0; // current fix data
uint8_t i;

#define SERIAL_SET   "$PMTK300,100,0,0,0,0*2C\r\n"

// GGA-Global Positioning System Fixed Data, message 103,00
#define LOG_GGA 0
#define GGA_ON   "$PSRF103,00,00,01,01*25\r\n"
#define GGA_OFF  "$PSRF103,00,00,00,01*24\r\n"

// GLL-Geographic Position-Latitude/Longitude, message 103,01
#define LOG_GLL 0
#define GLL_ON   "$PSRF103,01,00,01,01*26\r\n"
#define GLL_OFF  "$PSRF103,01,00,00,01*27\r\n"

// GSA-GNSS DOP and Active Satellites, message 103,02
#define LOG_GSA 0
#define GSA_ON   "$PSRF103,02,00,01,01*27\r\n"
#define GSA_OFF  "$PSRF103,02,00,00,01*26\r\n"

// GSV-GNSS Satellites in View, message 103,03
#define LOG_GSV 0
#define GSV_ON   "$PSRF103,03,00,01,01*26\r\n"
#define GSV_OFF  "$PSRF103,03,00,00,01*27\r\n"

// RMC-Recommended Minimum Specific GNSS Data, message 103,04
#define LOG_RMC 0
#define RMC_ON   "$PSRF103,04,00,01,01*21\r\n"
#define RMC_OFF  "$PSRF103,04,00,00,01*20\r\n"

// VTG-Course Over Ground and Ground Speed, message 103,05
#define LOG_VTG 0
#define VTG_ON   "$PSRF103,05,00,01,01*20\r\n"
#define VTG_OFF  "$PSRF103,05,00,00,01*21\r\n"

// Switch Development Data Messages On/Off, message 105
#define LOG_DDM 0
#define DDM_ON   "$PSRF105,01*3E\r\n"
#define DDM_OFF  "$PSRF105,00*3F\r\n"

#define USE_WAAS   0     // useful in US, but slower fix
#define WAAS_ON    "$PSRF151,01*3F\r\n"       // the command for turning on WAAS
#define WAAS_OFF   "$PSRF151,00*3E\r\n"       // the command for turning off WAAS

// read a Hex value and return the decimal equivalent
uint8_t parseHex(char c) {
  if (c < '0')
    return 0;
  if (c <= '9')
    return c - '0';
  if (c < 'A')
    return 0;
  if (c <= 'F')
    return (c - 'A')+10;

// blink out an error code
void error(uint8_t errno) {
  while(1) {
    for (i=0; i<errno; i++) {
      digitalWrite(led1Pin, HIGH);
      digitalWrite(led2Pin, HIGH);
      digitalWrite(led1Pin, LOW);
      digitalWrite(led2Pin, LOW);
    for (; i<10; i++) {

void setup()
  WDTCSR |= (1 << WDCE) | (1 << WDE);
  WDTCSR = 0;
  pinMode(led1Pin, OUTPUT);
  pinMode(led2Pin, OUTPUT);
  pinMode(powerPin, OUTPUT);
  digitalWrite(powerPin, LOW);

  if (!card.init_card()) {
    putstring_nl("Card init. failed!");
  if (!card.open_partition()) {
    putstring_nl("No partition!");
  if (!card.open_filesys()) {
    putstring_nl("Can't open filesys");
  if (!card.open_dir("/")) {
    putstring_nl("Can't open /");

  strcpy(buffer, "GPSLOG00.TXT");
  for (buffer[6] = '0'; buffer[6] <= '9'; buffer[6]++) {
    for (buffer[7] = '0'; buffer[7] <= '9'; buffer[7]++) {
      //putstring("\ntrying to open ");Serial.println(buffer);
      f = card.open_file(buffer);
      if (!f)
    if (!f)

  if(!card.create_file(buffer)) {
    putstring("couldnt create ");
  f = card.open_file(buffer);
  if (!f) {
    putstring("error opening ");
  putstring("writing to ");


  if (LOG_DDM)

  if (LOG_GGA)

  if (LOG_GLL)

  if (LOG_GSA)

  if (LOG_GSV)

  if (LOG_RMC)

  if (LOG_VTG)

  if (USE_WAAS)

void loop()
  //Serial.println(Serial.available(), DEC);
  char c;
  uint8_t sum;

  // read one 'line'
  if (Serial.available()) {
    c =;
    //Serial.print(c, BYTE);
    if (bufferidx == 0) {
      while (c != '$')
        c =; // wait till we get a $
    buffer[bufferidx] = c;

    //Serial.print(c, BYTE);
    if (c == '\n') {
      buffer[bufferidx+1] = 0; // terminate it

      if (buffer[bufferidx-4] != '*') {
        // no checksum?
        Serial.print('*', BYTE);
        bufferidx = 0;
      // get checksum
      sum = parseHex(buffer[bufferidx-3]) * 16;
      sum += parseHex(buffer[bufferidx-2]);

      // check checksum
      for (i=1; i < (bufferidx-4); i++) {
        sum ^= buffer[i];
      if (sum != 0) {
        //putstring_nl("Cxsum mismatch");
        Serial.print('~', BYTE);
        bufferidx = 0;
      // got good data!

      if (strstr(buffer, "GPRMC")) {
        // find out if we got a fix
        char *p = buffer;
        p = strchr(p, ',')+1;
        p = strchr(p, ',')+1;       // skip to 3rd item

        if (p[0] == 'V') {
          digitalWrite(led1Pin, LOW);
          fix = 0;
        } else {
          digitalWrite(led1Pin, HIGH);
          fix = 1;
      if (LOG_RMC_FIXONLY) {
        if (!fix) {
          Serial.print('_', BYTE);
          bufferidx = 0;
      // rad. lets log it!
      Serial.print('#', BYTE);
      digitalWrite(led2Pin, HIGH);      // sets the digital pin as output

      if(card.write_file(f, (uint8_t *) buffer, bufferidx) != bufferidx) {
         putstring_nl("can't write!");

      digitalWrite(led2Pin, LOW);

      bufferidx = 0;

      // turn off GPS module?
      if (TURNOFFGPS) {
        digitalWrite(powerPin, HIGH);

      digitalWrite(powerPin, LOW);
    if (bufferidx == BUFFSIZE-1) {
       Serial.print('!', BYTE);
       bufferidx = 0;
  } else {



void sleep_sec(uint8_t x) {
  while (x--) {
     // set the WDT to wake us up!
    WDTCSR |= (1 << WDCE) | (1 << WDE); // enable watchdog & enable changing it
    WDTCSR = (1<< WDE) | (1 <<WDP2) | (1 << WDP1);
    WDTCSR |= (1<< WDIE);

SIGNAL(WDT_vect) {
  WDTCSR |= (1 << WDCE) | (1 << WDE);
  WDTCSR = 0;

/* End code */
There is a lot of stuff there that I don't need, like sleepmode and customising GPS output. I need to clear it up. But the point is, the output I see on the PC and also logged to the card has missing sentences, as highlighted below:
7  Forum 2005-2010 (read only) / Interfacing / Simple GPS logging to SD with Duemilanove 368 on: September 01, 2010, 11:15:20 am
Its my first post, so Hi to everyone!
Was browsing this Arduino forum for quite a while now and find it very useful and found tons of good information here, well-done!.
My problem is though, I am trying to log data from Lycosys LS20031 10Hz GPS to an SD card without any conversion or parsing NMEA sentences.
I have tried code below from ladyada
(using hardware Serial interface), but it can't seems to cope with the data coming from GPS and misses some sentences. Even after I dropped the rate to 38400 it is still misses some. I can not go lower then 38400 as the GPS wouldn't work at 10Hz.
I have tried to go 5Hz and 19200 and only limited to GGA, GSA and RMC sentences and it improved a bit, but still missing some chunks of data.
I have checked the GPS itself, by using basic GPS test code below and it spits data on the screen perfectly.
void setup() {

void loop() {
  if (Serial.available()) {
    Serial.print(, BYTE);

I understand the problems are with hardware serial interface and reading the forums NewSoftSerial is the way to go, I have tried many different codes from various forums, but I can't find a good working code which would do NewSoftSerial and SD logging. Unfortunately, I am not a programmer, so it takes me quite a long time to figure out what the code does. I have attempted to merge two codes together, but no much luck there.

So, if anyone could point me in the direction of a good starting code to get SD logging with NewSoftSerial or any other alternatives.
Or if you could help me changing the code below to adopt NewSoftSerial, I would really appreciate this.
8  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Open Source Data Logger Project Using the Arduino? on: October 15, 2010, 10:58:15 am
I am very new to this field and I am building Data logger for a racing kart or a car. I think there should be a category for this type of loggers.
Although, they are similar to any other type of loggers, there are specific aspects of them being exposed to a very hostile environment i.e Rain/water/oil, vibration, EMI. I have faced this problems and finding ways to tackle them, as I am sure many others too. For example SD card slot doesn't take vibration very well and the card tend to move and eventually disconnects, which is not very healthy for logger in a middle of a busy logging session  ;D
It would be nice to share other ideas about the racing data loggers with fellow motorracing enthusiasts.
9  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Open Source Data Logger Project Using the Arduino? on: October 14, 2010, 11:53:28 am
I am thinking about creating a specific website which will act as a central resource for open source data logger projects, allowing the less technical to communicate with us with there project idea's.  Additionally, It might also work as a place for developers to share code between each other and exchange idea's.

I had plans on competitions, prizes, etc to generate interest and give some incentive for everyone to contribute, I have had both positive and negative comments on implementing this.

What do you you all think?  Good or bad idea?

I noticed that this thread has been viewed over 10,000 times!!  It would appear that there is a lot of interest out there.

I think it a brilliant idea! The views of this topic is nearly hitting 50,000! :o
So was the central depositry site for data logger projects created yet? ;D
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