Help with temperature sensor telemetry code

[Rob Bell]

Guys, I wonder if any of you out there are experts in programming? Tim Jenner has been working on an analogue to digital converter to work in conjunction with a laptop to log temperature over time. If we can get this all to work, then we have a powerful tool for measuring temperature over time to determine whether the electric water pump works, and indeed to look into other problems, including the oft discussed thermal cycling...

Tim has put together this bit of code - but the problem is that the channels refuse to read independently of one another. If one ignores 2 of the three channels, then that one channel records correctly - irrespective of which channel is being interrogated.

Any thoughts/ suggestions would be much appreciated!

Here's Tim's code comming up...

[Rob Bell]

[glow=red,2,300]PART ONE[/glow]

/* Project name: EPP Based MAX118 ADC Data Logger
* Filename: READADC.C
* File purpose: Drive ADC and log results *
* Notes: For safety, ensure ADC module is disconnected from parallel port until port has been set to bidrectional. This is to avoid possible conflicts between EPP output in unidirectional mode and ADC buffer
/
// Includes and definitions
#include <stdio.h>
#include <conio.h>
// inp() outp() kbhit()
#include <string.h>
// Parallel port details
#define BASE 0x378
// Base address for parallel port LPT1:
const unsigned int pdata = BASE; // Port data register
const unsigned int pstatus = BASE+1; // Port status register
const unsigned int pcont = BASE+2; // Port control register


// Parameters
unsigned int frequency = 1; // Frequency of samples in seconds
unsigned int num_samples = 3; // Number of samples to take before averaging
unsigned int stop_time = 5; // Number of seconds stop button must be held for
char filename[80] = "a:logfile.csv"; // Path to logfile


// Basics...
#define A0HI outp(pcont, (inp(pcont) & 0xfd) ) // Take pin 14 HI
#define A0LO outp(pcont, (inp(pcont) | 0x02) ) // Take pin 14 LO

#define SCHI outp(pcont, (inp(pcont) | 0x04) ) // Take pin 16 HI
#define SCLO outp(pcont, (inp(pcont) & 0xfb) ) // Take pin 16 LO

#define A1HI outp(pcont, (inp(pcont) & 0xf7) ) // Take pin 17 HI
#define A1LO outp(pcont, (inp(pcont) | 0x08) ) // Take pin 17 LO

#define A2HI outp(pcont, (inp(pcont) & 0xfe) ) // Take pin 1 HI
#define A2LO outp(pcont, (inp(pcont) | 0x01) ) // Take pin 1 LO

#define DATAIN outp(pcont, (inp(pcont) | 0x20) ) // Put port in INPUT mode
#define DATAOUT outp(pcont, (inp(pcont) & 0xdf) ) // Put port in OUTPUT mode

const int SUCCESS = 0;
const int FAIL = 1; // Constants for return values

const int RAW = 0;
const int AVERAGE = 1; // Constants for data display


// Function declarations
void print_header(void); // Prints header at top centre of screen
void print_raw_results(unsigned int data_1, unsigned int data_2, unsigned int data_3, int poi, int stop_counter); // Prints raw results to screen
void print_av_results (unsigned int av_data_1, unsigned int av_data_2, unsigned int data_3); // Prints average results to screen
unsigned int do_conversion(int input); // Returns ADC result from specified input
void print_params (void); // Prints parameter list
void set_params (void); // Alters parameters
void show_graph (unsigned int channel, unsigned int type, unsigned int data); // Prints results to screen in graphical form


// Start code proper
int main()
{
/* Main function */

int retval = 0; // Return values
int file_ok = FAIL; // So we know if there's a log file to write to
int count = 0; // Number of samples since last average
int inc = 0; // Temporary incremental counter
int status = 0; // Contents of status register
unsigned int data_1 = 0; // Raw ADC result from input IN1
unsigned int data_2 = 0; // Raw ADC result from input IN4
unsigned int data_3 = 0; // Raw ADC result from input IN7
unsigned int av_data_1 = 0; // Averaged result for input IN1
unsigned int av_data_2 = 0; // Averaged result for input IN4
unsigned int av_data_3 = 0; // Averaged result for input IN7
char line_string[80]; // Temporary string for int conversion
int poi = 0; // Point of Interest - set according to bit 7
int stop_counter = 0; // How long stop button has been held

// Put the port into bidirectional mode ASAP!
DATAIN;

clrscr();
print_header();

gotoxy(1, 10);
printf(" Parallel port placed in bidirectional mode.\n" );
printf(" Connect ADC module power, then data cable now.\n\n" );
printf(" Hit enter when module has been connected.\n" );
scanf("%c", retval);

// Let's get started, first print some status messages...
clrscr();
print_header();

// Print and optionally alter parameters...
print_params();
//!!! set_params();

// Tidy up screen...
clrscr();
print_header();
print_params();

// Get the log file open
FILE *logfile; // Obtain a file pointer
if ((logfile = fopen(filename, "w" )) == NULL) // Open logfile.csv for output and check for errors
{
gotoxy(40,21);
printf("WARNING:" );
gotoxy(42,22);
printf("Could not open logfile for writing" );
file_ok = FAIL; // Set flag so we know not to try to write to log
}
else
{
file_ok = SUCCESS; // Set flag so we know we can log results
gotoxy(40,21);
printf("Logging to:" );
gotoxy(42,22);
printf(filename);

// Write column headers to file...
fputs("IN1,IN2,IN3,POI\n", logfile);
// Close file, then reopen for append to check for errors before filling disk buffer!
retval = fclose (logfile);
logfile = fopen(filename, "a" );

} // end if

// Keep going until a key is pressed
while (!kbhit())
{
// Print some status messages...
gotoxy(1, 22);
printf(" Press any key to stop logging\n" );

gotoxy(10, 24);
if (file_ok == SUCCESS)
printf(" Sampling and logging ³" );
else
printf("Sampling - not logging ³" );

count++;
gotoxy(45, 24);
printf("Samples since last average : %2u", count);

// Get raw samples
data_1 = do_conversion(1);
data_2 = do_conversion(4);
data_3 = do_conversion(6);

// Add samples for averaging
av_data_1 += data_1;
av_data_2 += data_2;
av_data_3 += data_3;

// Now print the results to the screen...
print_raw_results(data_1, data_2, data_3, poi, stop_counter);
show_graph(1, RAW, data_1);
show_graph(2, RAW, data_2);
show_graph(3, RAW, data_3);

if (count == num_samples)
{
// Taken enough samples to average
av_data_1 /= num_samples;
av_data_2 /= num_samples;
av_data_3 /= num_samples;

// Do some stuff with averaged values...
print_av_results(av_data_1, av_data_2, av_data_3); // This will print over the raw results, so...
print_raw_results(data_1, data_2, data_3, poi, stop_counter); // ...reprint them

// Plot average results...
show_graph(1, AVERAGE, av_data_1);
show_graph(2, AVERAGE, av_data_2);
show_graph(3, AVERAGE, av_data_3);

// Write averaged values and poi indicator to log file if there is one
if (file_ok == SUCCESS)
{
sprintf(line_string, "%d", av_data_1); // Convert reading to string
fputs(line_string, logfile); // Dump value to file
fputs(",", logfile); // Insert column separater
sprintf(line_string, "%d", av_data_2);
fputs(line_string, logfile);
fputs(",", logfile);
sprintf(line_string, "%d", av_data_3);
fputs(line_string, logfile);
fputs(",", logfile);
sprintf(line_string, "%d", poi);
fputs(line_string, logfile);
fputs("\n", logfile); // New line for next readings
} // end if

// Reset averaging counters
count = 0;
av_data_1 = 0;
av_data_2 = 0;
av_data_3 = 0;
} // end if

inc = 0;
for (inc; inc < frequency; inc++)
{
sleep(1);
status = (inp(pstatus) & 0xA0); // Return val of bits 7 and 5

switch (status)
{
case (0):
// Bits 7 and 5 low
poi = 0;
stop_counter++;
break;
case (32):
// Bit 7 low, bit 5 high
poi = 0;
stop_counter = 0;
break;
case (128):
// Bit 7 high, bit 5 low
poi = 1;
stop_counter++;
break;
case (160):
// Bits 7 and 5 high
poi = 1;
stop_counter = 0;
break;
default:
// Should never happen!
printf("UNKNOWN STATUS PATTERN READ!\n" );
break;
} // End case

[Rob Bell]

[glow=red,2,300]PART TWO[/glow]

gotoxy(5,20);
printf("Stop counter %i, Stop time %i", stop_counter, stop_time);
print_raw_results(data_1, data_2, data_3, poi, stop_counter); // Update raw results to show POI/STP
if (stop_counter >= stop_time)
{
// Stop button held for long enough, break out
// Close log file if there was one
if (file_ok == SUCCESS)
{
gotoxy(40, 21);
printf("Closing log file..." );
retval = fclose (logfile);
} // end if
exit(SUCCESS);
}
} // end for
} // end while

// Close log file if there was one
if (file_ok == SUCCESS)
{
gotoxy(40, 21);
printf("Closing log file..." );
retval = fclose (logfile);
} // end if

return (SUCCESS);
} // End main




void print_header()
{
/*
* Prints header at top centre of screen and stop message at bottom
*/

gotoxy(1, 1);
printf(" ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ»\n" );
printf(" ºEPP/MAX118 ADC Driver and Data Logger - v0.1º\n" );
printf(" ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ\n\n" );

gotoxy(1, 23);
printf(" ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ" );
gotoxy(12, 24);
printf("Not yet sampling ³" );
gotoxy(1, 25);
printf(" ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ" );

} // End print_header




void print_raw_results(unsigned int data_1,
unsigned int data_2,
unsigned int data_3,
int poi,
int stop_counter)
{
/* Prints results of raw ADC conversion to screen */

gotoxy(1, 10);
printf(" Raw results:\n" );
printf(" IN1 : %3u\n", data_1);
printf(" IN2 : %3u\n", data_2);
printf(" IN3 : %3u\n", data_3);
printf(" POI : %i\n", poi);
printf(" STP : %i\n", stop_counter);

} // End print_raw_results




void print_av_results(unsigned int av_data_1,
unsigned int av_data_2,
unsigned int av_data_3)
{
/* Prints results of averaged ADC conversion to screen */

gotoxy(1, 10);
printf(" Averaged results:\n" );
printf(" IN1 : %3u\n", av_data_1);
printf(" IN2 : %3u\n", av_data_2);
printf(" IN3 : %3u\n", av_data_3);

} // End print_av_results




unsigned int do_conversion(int input)
{
/* Performs ADC conversion on specified input channel and returns raw result */

unsigned int result = 0; // Stores result of conversion

// Set ADC address lines to select input channel
switch(input)
{
case 1:
// Input IN1 chosen
A0LO;
A1LO;
A2LO;
break;
case 4:
// Input IN4 chosen
A0HI;
A1HI;
A2LO;
break;
case 6:
// Input IN6 chosen
A0HI;
A1LO;
A2HI;
break;
default:
// Default - should never happen, panic!
printf("SOMETHING'S GONE VERY WRONG! INVALID INPUT CHANNEL SELECTED.\n" );
} // end case

// Initiate conversion by pulsing SC* low
SCLO;
SCHI;

// Read result...by the time we've got here, result should be ready
result = inp(pdata);

return (result);
} // End do_conversion




void print_params()
{
/* Prints parameter list */

gotoxy(1,5);
printf("Parameters:\n" );
printf(" Sampling every %u second(s)\n", frequency);
printf(" Averaging every %u samples\n", num_samples);
printf(" Logfile : %s\n\n", filename);
} // end print_params




void set_params()
{
/* Changes default parameter values */

printf("Enter sampling frequency in seconds: " );
scanf("%u", frequency);

printf("Enter number of samples to average: " );
scanf("%u", num_samples);

printf("Enter full path to logfile: " );
scanf("%s", filename);

print_params();
} // end set_params




void show_graph(unsigned int channel,
unsigned int type,
unsigned int data)
{
/*
* Prints results in graphical form
*/

const int height_of_graph = 15; // Distance between top and bottom of graph
const int units_per_block = 17; // Number of ADC units per block
const int base_of_graph = 19; // Row to use as bottom of graph
const int top_of_graph = base_of_graph-height_of_graph;
int xpos = 0; // Coord dependant on channel and data type
int current_plot = 0; // Coord of current y position to plot
int num_blocks = 0; // Number of blocks reading gets

// Set column depending on channel and type of data
switch (channel)
{
case 1:
// Input 1
if (type == RAW)
xpos = 50;
else
xpos = 52;
break;
case 2:
// Input 2
if (type == RAW)
xpos = 60;
else
xpos = 62;
break;
case 3:
// Input 3
if (type == RAW)
xpos = 70;
else
xpos = 72;
break;
default:
// Should never happen
printf("Invalid channel selected!" );
} // end case

// Print top and bottom of graph
gotoxy(46, base_of_graph-1); // Bottom of graph
printf("0 ¯" );
gotoxy(40, base_of_graph); // Legend
printf("Channel ¯" );
gotoxy(xpos, base_of_graph); // Labels
printf("%i", channel);
gotoxy(44, top_of_graph); // Top of graph
printf("255 ¯" );

// Data may be 0-255; Use 15 rows to display, thus 255/15=17 units per block
// Bottom of graph is 6 from end of screen, ie. row 19.
num_blocks = data/units_per_block;

current_plot = top_of_graph;
for (current_plot; current_plot < base_of_graph; current_plot++)
{
gotoxy(xpos, current_plot);
if (current_plot >= (base_of_graph-num_blocks))
{
if (type == RAW)
printf("°" );
else
printf("²" );
}
else
printf("." ); // Blank previous plots
}
} // end show_graph

[Rob Bell]

I can email anyone how is interested Tim's original code if they'd prefer - just let me know!

[TimW]

Surely it's blindingly obvious...!!!!!!

[Rob Bell]

TimW said:

Surely it's blindingly obvious...!!!!!!

My thoughts exactly...

err...

[Rob Bell]

Thanks to Tim, I now have the code in pdf format to down load: www.mgcars.org.uk/carclub/mgfregister/temp/inprog.pdf

Defintely a lot easier to read this way!

Cheers

[ScarletFever]

Sorry guys can't help with this one - might as well be double dutch for all i know!

[dave]

I used to know Cobol and a bit of Assembler, but I guess that was a few years ago now

[TimW]

Of course, depending how precious Tim is of the code, it would be a natural choice to have a chat with Carl at Emerald, I think he is perfectly placed to advise on the code, albeit it might get incorporated into the next Emerald software release

Tim

[Rob Bell]

dave said:

I used to know Cobol and a bit of Assembler, but I guess that was a few years ago now

Major respect Dave! Unfortunately, my programming extended as far as BBC BASIC, a bit of 6502 assembler and I've dabbled a little bit in C/ Java/ html...

But why Tim's code doesn't work as it should elludes me

Tim, would Karl be prepared to look at this code for gratis? For a guru responsible for the Emerald M3D map, it shouldn't present him with too much of a problem...

[apttony]

I've just downloaded the code & will have a look - no promises though

[Rob Bell]

Thanks Tony - you're a star!

[apttony]

Message for Tim Jenner:

Tim,
I've only had a quick look so far & have not as yet used this device, and I am not sure of the h'ware aspects that this is built into, so bear with me if I'm covering ground you have already looked at.

1: MAXIM 118 spec says that when power is first applied, a conversion should be performed to initialize the MAX118, but disregard the data output. I don't see that in the code.

2: DATAIN: does pcont need to be initialised by forcing it to a specific bit pattern rather than bitwise inclusive OR with an arbitary unknown state on power-up.

3: Again, I don't know the hardware build, but are delays reqd when addressing the ADC's. The spec talks of a min time before conversion time e.g. 260 ns?

4. Similarly there could be a delay reqd while conversion takes place.

5. Since it apparently works on just one address, it could be the lack of delays when moving on to the next address.

Rob: Is there an easier way of talking with Tim? ;D

[Rob Bell]

Tony, Tim reads the forum, but because of work comitments, he's often away from base. I'll get Tim to email you?