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delene
Joined: 13 Oct 2003
Posts: 32
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 Posted: Mon Jul 21, 2008 1:17 pm |
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My code also returns -4.6 and -39.9... :(
I have tried the suggestions above and still no joy
Any other suggestions??? |
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tony-montana
Joined: 12 Jan 2009
Posts: 1
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| help |
| Posted: Mon Jan 12, 2009 11:12 am |
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hello. I have a problem with the sensor sht1xx and I'm using the same program that I was going to sht75 temperature and gives me a very rare. Can you help me thanks.
| Code: | void sensor ()
(
sht_rd (restemp, truehumid) / / measure and calculate
lcd_gotoxy (1.1) / / write in 1.1
printf (lcd_putc, "Temp:% 3.1f% cC" restemp, 223); / / sensor
printf (lcd_putc, "\ nRH:%%% 3.1f" truehumid); / / sensor
) |
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Pol
Joined: 07 Sep 2006
Posts: 1
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| Driver For SHT75 Temperature & Humidity Sensor |
| Posted: Wed Jan 21, 2009 4:29 am |
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Hello, i have a problem with this driver , i use 18f1320 @ 8mhz : i don't have answer from sensor, but if tune up the pic-clock (to 16mhz) the sensor start to answer me.... where is the clock-dependent sub of this cod ??? Thanks...
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asmallri
Joined: 12 Aug 2004
Posts: 1660
Location: Perth, Australia
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| Re: Driver For SHT75 Temperature & Humidity Sensor |
| Posted: Wed Jan 21, 2009 8:09 am |
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| Pol wrote: | | Hello, i have a problem with this driver , i use 18f1320 @ 8mhz : i don't have answer from sensor, but if tune up the pic-clock (to 16mhz) the sensor start to answer me.... where is the clock-dependent sub of this cod ??? Thanks... |
Sound like you might be missing the pull up resistors.
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Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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Diego Oliveira
Joined: 10 Aug 2008
Posts: 3
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| Posted: Fri Jan 23, 2009 12:26 pm |
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Someone has a library of SHT75 to PIC18F, I have already commented on the changes in the forum but none solved.
Grateful for the attention. |
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asmallri
Joined: 12 Aug 2004
Posts: 1660
Location: Perth, Australia
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crocu
Joined: 02 Nov 2009
Posts: 5
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| Posted: Mon Nov 02, 2009 4:49 am |
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Well, some of you you say that read temperature is too high.
Can someone confirm that sht75 code works fine ?
Can you post a sht75 code that works well with any PIC familly ?
+ electronic schematic ?
( Hex file would be also much appreciated )
I would like to display on a LCD, temperature and humidity.
Many thanks for your help. |
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Nun
Joined: 19 Nov 2009
Posts: 1
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| Posted: Thu Nov 19, 2009 5:57 am |
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Hi!
Mi sht71 sensor is giving me this temperature and humidity results. Can it be a problem of constants when it calculates the real temp &humid? or is it another problem?
T=-11.930000 & H=79.984183
T=592.229974 & H=-1185.778036
T=103.270001 & H=286.722098
T=195.430003 & H=300.089928
T=-11.930000 & H=79.984183
T=592.229974 & H=-1185.778036
T=103.270001 & H=286.722098
T=195.430003 & H=300.089928
I used the library at the beggining of the topic, just changing the values of this function according the datasheet I downloaded from sensirion's web page
| Code: | void calculate_data (int16 temp, int16 humid, float & tc, float & rhlin, float & rhtrue)
{
float truehumid1, rh;
//calculate temperature reading
tc = ((float) temp * 0.04) - 40.1;
//calculate Real RH reading
rh = (float) humid;
rhlin = (rh * 0.0367) - (rh * rh * 0.0000015955) - 2.0468;
//calculate True RH reading
rhtrue = ((tc - 25.0) * (0.01 + (0.00008 * rh))) + rhlin;
}
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kizuc
Joined: 25 Aug 2009
Posts: 6
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| LCD to use |
| Posted: Wed Nov 25, 2009 8:38 pm |
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Thanks for the driver because I have been able to use it with 18f4550. But I have a problem with the display. Kindly recommend an LCD that can work well with this setup. Or how can I use a 7 segment display for this code ? Especially getting the driver for the 7 segment display.
Thanks |
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jecottrell
Joined: 16 Jan 2005
Posts: 559
Location: Tucson, AZ
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| Posted: Sun Feb 28, 2010 1:48 pm |
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| delene wrote: | My code also returns -4.6 and -39.9... :(
I have tried the suggestions above and still no joy
Any other suggestions??? |
I know this is an old topic, but I thought I'd post for future readers...
I had a similar problem after laying out a new board and accidentally swapping the data and clock lines. Got them squared away and it works fine.
So, double check your pin defines in the driver file. |
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n_barroca
Joined: 13 Jul 2010
Posts: 2
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| Re: Driver For SHT75 Temperature & Humidity Sensor |
| Posted: Tue Jul 13, 2010 8:07 am |
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Hello can you send me the code you use to LCD?
Thanks. |
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stijn023
Joined: 28 Sep 2010
Posts: 49
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| program |
| Posted: Tue Sep 28, 2010 4:45 am |
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Hi,
I'm using one of these sensors you used.
But my question is which c program do you used to program it?
Thanks in advance |
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pisisik44
Joined: 01 Nov 2010
Posts: 1
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| Posted: Mon Nov 01, 2010 6:42 am |
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Hi. If I use 16F84A at 32 KHz or 4 MHz, does it occur any problem?
Thanks for help. |
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atai21
Joined: 30 Dec 2010
Posts: 31
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| Posted: Tue Mar 01, 2011 8:50 pm |
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| Code: | #include <18F4550.h>
#fuses HS,NOWDT,PUT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_B0,stream=ser)
#use rs232(baud=9600, xmit=PIN_B1,stream=ser1)
#include<lcd.c>
#include<sht75.c>
#byte PORTB = 0xf81
#byte PORTC = 0xf82
#define fanA PIN_C2
#define fanB PIN_C5
#define buzzer PIN_C6
#define nozzle PIN_C7
void main()
{
float tempC, humidRH;
lcd_init();
sht_init();
printf(lcd_putc, "\b~WELCOME~ ",);
printf(lcd_putc, "\bTEMP&RH READER ",);
while(1)
{
sht_rd (tempC, humidRH);
lcd_gotoxy(1,1);
printf(lcd_putc, "Temp : %3.1f %cC ", tempC, 223);
printf(lcd_putc, "\nRH : %3.1f %% ", humidRH);
output_high(fanA);
}
if (tempC>25)
{
output_high(fanA);
output_high(fanB);
}
else if (tempC>35 && humidRH<=50)
{
output_high(fanA);
output_high(fanB);
}
else if (tempC>90 && humidRH<=15)
{
output_high(fanA);
output_high(fanB);
output_high(nozzle);
output_high(buzzer);
printf(lcd_putc, "WARNING!!! ",);
delay_ms(500); //delay 500 ms between reading to prevent self heating of sensor
}
{
}
}
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Hi all,
i use this code for 18f4550 and sht75.the problem is my LCD did not display anything.may i know what is wrong? |
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microman
Joined: 11 Apr 2011
Posts: 1
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| pic16f877a sht75 |
| Posted: Mon Apr 11, 2011 9:55 am |
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Hey the code works initially but the temperature never increases or decreases. I checked the clock signal and there is no clock signal. I am really struggling can anybody help please.
n.b. I am using a 4mhz crystal.
The code is exactly the same as previously just changed the pin definition. |
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