reading si7021 humy_temp sensor

[iw2fvo]

hi to all in this forum,
Is there somebody that used the si7021 sensor with pbp please ?
Any sample program available ?
thanks
Ambrogio

[alec]

This is a program I wrote a while back to read a barometer and a humidity/temperature sensor

Good luck

'****************************************************************
'*  Name    : 18F45K223_HDU21D_test.pbp                                      *
'*  Author  : [select VIEW...EDITOR OPTIONS]                    *
'*  Notice  : Copyright (c) 2015 [select VIEW...EDITOR OPTIONS] *
'*          : All Rights Reserved                               *
'*  Date    : 7/21/2015                                         *
'*  Version : 1.0                                               *
'*  Notes   :                                                   *
'*          :                                                   *
'****************************************************************
'********************DEVICE CONFIGURATION**********************************
#CONFIG
    CONFIG  FOSC = INTIO67        ; Internal oscillator block
    CONFIG  PLLCFG = OFF          ; Oscillator used directly
    CONFIG  PRICLKEN = OFF        ; Primary clock can be disabled by software
    CONFIG  FCMEN = OFF           ; Fail-Safe Clock Monitor disabled
    CONFIG  IESO = OFF            ; Oscillator Switchover mode disabled
    CONFIG  PWRTEN = OFF          ; Power up timer disabled
    CONFIG  BOREN = SBORDIS       ; Brown-out Reset enabled in hardware only (SBOREN is disabled)
    CONFIG  BORV = 190            ; VBOR set to 1.90 V nominal
    CONFIG  WDTEN = ON            ; WDT is always enabled. SWDTEN bit has no effect
    CONFIG  WDTPS = 32768         ; 1:32768
    CONFIG  CCP2MX = PORTC1       ; CCP2 input/output is multiplexed with RC1
    CONFIG  PBADEN = OFF          ; PORTB<5:0> pins are configured as digital I/O on Reset
    CONFIG  CCP3MX = PORTB5       ; P3A/CCP3 input/output is multiplexed with RB5
    CONFIG  HFOFST = ON           ; HFINTOSC output and ready status are not delayed by the oscillator stable status
    CONFIG  T3CMX = PORTC0        ; T3CKI is on RC0
    CONFIG  P2BMX = PORTD2        ; P2B is on RD2
    CONFIG  MCLRE = EXTMCLR       ; MCLR pin enabled, RE3 input pin disabled
    CONFIG  STVREN = ON           ; Stack full/underflow will cause Reset
#ENDCONFIG
'*************************DEFINEs*******************************************
DEFINE OSC 16 ' Tell PBP the expected systemclock frequency
' LCD settings
' Set LCD Data port
DEFINE LCD_DREG PORTB
' Set starting Data bit (0 or 4) if 4-bit bus
DEFINE LCD_DBIT 0
' Set LCD Register Select port
DEFINE LCD_RSREG PORTB
' Set LCD Register Select bit
DEFINE LCD_RSBIT 4
' Set LCD Enable port
DEFINE LCD_EREG PORTB
' Set LCD Enable bit
DEFINE LCD_EBIT 5
' Set LCD bus size (4 or 8 bits)
DEFINE LCD_BITS 4
' Set number of lines on LCD
DEFINE LCD_LINES 2
' Set command delay time in us
DEFINE LCD_COMMANDUS 1500
' Set data delay time in us
DEFINE LCD_DATAUS 44
define ADC_BITS 10
'define ADC_SAMPLEUS 50
define I2C_HOLD 1   'allow slave to hold bus low
'************************ALIASES***********************************************
'click boards - addresses from easypic7 board
'click slot 1
'click slot 2
CS          var portA.5
SCL         var portC.3
SDA         var portC.4
'************************Constants**********************************************
'LCD commands
command con $FE
clr     con $01
home    con $02
line1   con $80
line2   con $C0
trig_temp   con $E3
trig_RH     con $E5
HTU21D_i2c_address con $40
MPL3115A2_i2c_address   con $60
control con %10100000
'************************VARIABLES**********************************************
adval1  Var word
adval1_dig  var byte
adval1_dec  var word
adval2  var word
adval2_dig  var byte
adval2_dec  var word
period  var word
dtycycl var byte
X   var byte    'variable for the counter
memory  var word
Temp    var word
Temp1   var long
RH      var word
RH1     var long
deg_F   var word
HTU21D_i2c_address1    var byte
MPL3115A2_i2c_address1  var byte

P_status    var byte
out_P_MSB   var byte
out_P_CSB   var byte
out_P_LSB   var byte
out_T       var word
Pressure    var long
'********************INITIALIZE REGISTERS***************************************
init:
TrisA = %00000011
TrisB = %00000000
TrisC = %00010000
TrisE = %00000001
OSCCON = %01110010
OSCCON2 = %00000100
ANSELA = %00000011 'RA0, 1 analog, others digital
ANSELB = %00000000 'all others digital
ANSELC = %00000000
ANSELD = %00000000
ANSELE = %00000000
ADCON1 = %00001000 'AD Vre3f+ connected to FVR BUF2
ADCON2 = %10010111 'right justified, 4Tad aquisition time, Frc clock derived from internal oscilator
VREFCON0 = %10100000 'internal voltage refernce enabled, set to 2.048 Vdc
CCP2CON = %00001100 'single outputP2A modulated

' PROGRAM CODE
pause 1500      'allow LCD to wake up
lcdout command, clr
pause 20
lcdout command, line1, "hello world"
pause 5000
lcdout command, clr
pause 20
HTU21D_i2c_address1 = HTU21D_i2c_address <<1
MPL3115A2_i2c_address1 = MPL3115A2_i2c_address<<1
Main:
i2cwrite SDA, SCL, HTU21D_i2c_address1, [trig_temp]
pause 10
i2cread SDA, SCL, HTU21D_i2c_address1, [temp]
pause 10
i2cwrite SDA, SCL, HTU21D_i2c_address1, [trig_RH]
pause 10
i2cread SDA, SCL, HTU21D_i2c_address1, [RH]
temp.1 = 0
Temp.0 = 0
RH.1 = 0
RH.0 = 0
RH1 = rh ** 12500
rh1 = RH1 - 600
temp1 = temp ** 17572
temp1 = temp1 - 4685
deg_F = ((Temp1 *9)/5) + 3200
lcdout command, line1, dec2 deg_F/100, ".", dec1 deg_F//100, " ", 223, "F ", dec2 RH1/100, ".", dec1 RH1//100, " %RH"
pause 10
i2cwrite SDA, SCL, MPL3115A2_i2c_address1, $26, [%00000011]
pause 20
i2cread sda, scl, MPL3115A2_i2c_address1, $00, [P_status, out_P_MSB, out_P_CSB, out_P_LSB, out_T]
pressure = 0
pressure.byte2 =   out_P_MSB
pressure.byte1 =   out_P_CSB
pressure.byte0 =   out_P_LSB
pressure = pressure>>6
pressure = Pressure * 10000
pressure = pressure / 338639
'pressure = pressure/33864
'out_T = out_T>>3
lcdout command, line2, dec2 pressure/100, ".",dec2 pressure//100, " in Hg"
'lcdout command, line2, dec6 out_T, " ", 223, "C"
pause 2000
goto main
 
end

[iw2fvo]

thanks Alec,
Ambrogio