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young
Joined: 24 Jun 2004
Posts: 285
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young
Joined: 24 Jun 2004
Posts: 285
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 Posted: Fri Aug 20, 2004 1:29 pm |
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| Ok I find out on application sheet |
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Guest
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| Posted: Fri Aug 20, 2004 2:27 pm |
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| As I posted |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Aug 20, 2004 2:55 pm |
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I think you want someone to write a driver for you.
Quantum has a forum:
http://www.qprox.com/forum/list.php?f=1
You should post a message on that forum, and
ask for C source code for a driver for the QT300.
They have an Evaluation board, the EA3, which has
a PIC 16LF73 on it. It runs the QT300 chip. Here
is the Evaluation board manual with a full schematic.
http://www.qprox.com/downloads/manuals/e3a_101.pdf
Ask them for the source code for the PIC on that
evaluation board.
Their forum will be your best resource. |
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Kenny
Joined: 07 Sep 2003
Posts: 173
Location: Australia
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| Posted: Fri Aug 20, 2004 4:35 pm |
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I have a sample and have tested it with a small routine.
The main point with this chip is that the spi clock frequency must be below about 40kHz, so timer 2 division was required.
Also, a 10k pullup resistor is needed on DRDY.
The output is logarithmic and decreases with increase in capacitance.
The data sheet is a bit short of information.
I found this post helpful:
http://www.qprox.com/forum/read.php?f=1&i=701&t=699#reply_701
My test routine
| Code: |
#include <16f876.h>
#use delay(clock=16000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#fuses HS,NOWDT,PUT,NOPROTECT,NOLVP
#define REQ PIN_C0
#define DRDY PIN_C1 // 10k pullup required
void main(void)
{
int32 temp32;
int8 hibyte,lobyte;
// Need spi clock with clock pulse width of >12uS or 24uS total period with
// space. ie. below about 40kHz. Can't get this with Fosc division, so have
// to use timer 2 option.
// T2 is usually used for tick counter 1mS (1kHz) and spi clock is this
// divided by 2 ie. 500Hz.
setup_spi(SPI_MASTER|SPI_L_TO_H|SPI_CLK_T2);
// System 1ms tick.
// The cycle time will be (1/clock)*4*t2div*(period+1)
// In this program clock=16,000,000 and period=249
// (1/16000000)*4*16*250=1000 us or 1kHz)
setup_timer_2(T2_DIV_BY_16,249,1);
// Edited to give a more reliable powerup
output_bit(REQ,1);
output_float(DRDY);
delay_ms(1000);
// Chip starts acquiring data on it's own at power up.
// Looks like it doesn't pull DRDY low when finished.
// Do dummy reads to get it to go back to sleep (says
// so in data sheet).
hibyte = spi_read(0);
delay_us(50); // >12uS
lobyte = spi_read(0);
output_float(DRDY);
delay_ms(1);
while(1)
{
output_bit(REQ,0);
delay_us(50); // >30uS
output_bit(REQ,1);
while(input(DRDY));
hibyte = spi_read(0);
delay_us(15); // >12uS
lobyte = spi_read(0);
output_float(DRDY);
temp32 = ((int32) hibyte << 8) + (int32) lobyte;
printf("%3u %3u %8lu\n\r",hibyte,lobyte,temp32);
delay_ms(100);
}
}
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Last edited by Kenny on Sun Sep 05, 2004 9:42 pm; edited 2 times in total |
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Guest
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| Posted: Mon Aug 23, 2004 9:23 am |
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Thank you kenny and PCM:
Is that you connected like this way as your program shown:
DRDY C1 //10k pull up
REQ C0
sck sck
sdi sdo
I used 16f819 so I connected
DRDY RB5
REQ RB6
sck sck
sdi sdo
and changed the program accordingly, but I could not get nothing. It looks that the program is loop somewhere in
while(input(DRDY));
would you provide me some more advice about it |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Mon Aug 23, 2004 10:23 am |
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| Did you put the pullup on the DRDY line? Did you change the DRDY #define? |
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Guest
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| Posted: Mon Aug 23, 2004 10:31 am |
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| Yes I did. |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Mon Aug 23, 2004 11:34 am |
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| Post you test program to make sure that you haven't overlooked something. |
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Guest
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| Posted: Mon Aug 23, 2004 12:22 pm |
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Thank you Mark, here is the program:
| Code: |
#if defined(__PCM__)
#include <16F819.h>
#fuses INTRC_IO,NOWDT,NOPROTECT,NOLVP
#use delay(clock=8000000)
#use rs232(baud=9600, parity=N, xmit=PIN_B7, rcv=PIN_B6) // Jumpers: 8 to 11, 7 to 12
//#include <lcd420_1.c>
//#include <math.h>
void LCDSetGeometry();
void LCDReset();
void LCDinit();
void LCDSetCursorPos(int8 x, int8 y);
#define REQ PIN_A6
#define DRDY PIN_B5
void main()
{
// setup_comparator(NC_NC_NC_NC);
int16 Capa; //capacitor data on sensors;
int8 hibyte,lowbyte;
// set_comparator(NC_NC_NC_NC);
Capa=0;
LCDinit();
setup_spi(SPI_MASTER | SPI_L_TO_H | SPI_CLK_T2);
setup_timer_2(T2_DIV_BY_16,249,1);
output_high(REQ);
output_float(DRDY);
delay_ms(1);
while(1)
{
// LCDOnOff(1);LCDTab();
LCDSetCursorPos(1, 0); //1 col 0 row
puts("Capacity Read\n");
//read QT300
output_low(REQ);
delay_us(35);
output_high(REQ);
while(input(DRDY));
hibyte=spi_read(0);
delay_us(15);
lowbyte=spi_read(0);
output_float(DRDY);
Capa=((int32)hibyte<<8)+(int32)lowbyte;
LCDSetCursorPos(1, 1);
printf("C=%lu", Capa);
delay_ms(100);
}
}
void LCDSetGeometry()
{
putc(15);
delay_ms(10);
putc(16);
delay_ms(10);
putc(0x80);
delay_ms(10);
putc(0xc0);
delay_ms(10);
putc(0x80);
delay_ms(10);
putc(0x80);
delay_ms(10);
}
void LCDReset()
{
putc(14);
delay_ms(1000);
}
void LCDinit()
{
// Set LCD Geometry
LCDSetGeometry();
// LCDReset
LCDReset();
}
void LCDSetCursorPos(int8 x, int8 y)
{
putc(17);
putc(y);
putc(x);
delay_ms(100);
}
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when I did not marked off while(input(DRDY)); on the LCD only CApacity Read shown, if I marked off while(input(DRDY)); C=65535 shown on LCD also. |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Mon Aug 23, 2004 12:46 pm |
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You said that
Did you mean that REQ was on RA6? |
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Guest
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| Posted: Mon Aug 23, 2004 1:16 pm |
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| Yes, I found that Iused it as RS232 so, I changed it to Pin_A6 |
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Guest
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| Posted: Mon Aug 23, 2004 2:10 pm |
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I changed and test a litlle bit the program to see if it was the
put the program into a endless loop, appearantly it is. so it means that the DRQY is not ready at all the time.
I also pullup REQ, pulldownSCK and SDO with a 10k resistor. |
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Kenny
Joined: 07 Sep 2003
Posts: 173
Location: Australia
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| Posted: Mon Aug 23, 2004 10:28 pm |
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I saw your post on the Quantum forum. Perhaps by using the cloning adaptor you have placed the chip into spi master mode. If so, return it to the default spi slave mode. I don't have these tools so can't comment on their use.
Edited on 26th August 2004:
For the archives, here is the link to the C source referred to by PCM Programmer. It was given in reply to Young's request on the Quantum forum. The code uses bit-banging for the spi and may be useful to anyone wanting to use this chip with a pic that doesn't have the MSSP module.
Quote:
To get the C code for the SPI
log on to our ftp server at ftp://81.2.82.89
username:anonymous
password:[your email address]
make sure you connect using 'port' connection not 'pasv'. The file you need is in the folder Design_files/LCD_spi.zip
Unquote.
Nice to see that they also use CCS :-)
Last edited by Kenny on Sun Sep 05, 2004 9:33 pm; edited 2 times in total |
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Guest
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| Posted: Tue Aug 24, 2004 7:29 am |
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Hi Kenny:
How do you decide master chip (16f819) timer2 to setup SPI speed, MSB/LSB spacing, span width and accquisition speed? I think it might be here that I made something wrong. |
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