ChrisHelvey
- 18th June 2009, 22:54
Hi all,
I still consider myself new to PicBasic Pro and in fact, to any programming, and I could really use a second set of eyes on this little piece of my project.
I am using a 12f683, a 20 Mhz Oscillator, two separate Pots for ADC input on channel 0 (GP0) and channel 3 (GP4) and the HPWM output (GP2.)
Below is the code, but here is the overall plan:
1st it reads the AN3 pot to get a static variable which will ultimately be a number between 80 and 175. This will not change again while the program is "looping."
Then it gets a varying voltage from AN0. That part works perfectly.
I can't get AN3 to read anything other than 0 even though there is 2V there.
Methinks my setup is wrong but to me, it seems like that is what the data sheet wants. Thanks for any input you have. I really appreciate it. Being a beginner is really HARD.
DEFINE OSC 20 '20 Mhz clock
DEFINE ADC_BITS 10 ' This requires a "Word" variable
DEFINE ADC_CLOCK 3 'Uses internal RC clock
DEFINE ADC_SAMPLEUS 20 'Microsecond sample time
'SETUP
'-------------------------
TRISIO = %00011001 ' AN0 (GPIO.0) and AN3 (GPIO.4) and GPIO.3 inputs
'Analog to Digital Converter Configuration
ANSEL = %00001001 ' Select AN0,3 as analog input (0 Will not work on EasyPIC dev)
ADCON0 = %10001101 ' Right justify result, AN3 selected, ADC On
'-----------------------------------------------------
Pauseus 10
' Delay to allow for VREF to settle
'------------------------------------------------------------------
'#### VARIABLES ######
adval var Word ' Create adval to store result
x var Byte ' "For" temp variable
adavg VAR Word ' Average of the AD input
Modifier VAR Byte 'Modifier value from above A/D conversion
DutyCycle1 VAR WORD 'Duty Cycle 1-255 for HPWM for O2-1
Vin1 Var word
'Temp for DIV32 math
dc1tmp VAR WORD '
'-------------------------------------------------------------------
'Begin the program
x=0 'Re-Set the initial variables and get ADC for modifier value
adavg = 0 '(80%-175%)
adval= 0
'1st get the modifier value
Repeat
ADCIN 3 , adval ' Read channel 3 to adval
adavg = adavg + adval 'Keep adding readings together
x = x +1 'Increment temporary "x" variable
until x = 31 'Until we add 8 samples
adavg = adavg/32 'Then Average the readings of 32 samples
Modifier = adavg/4 'Modifier becomes the averaged sample as 8 bits
if Modifier > 175 then
Modifier = 175 'Don't go over 175%
endif
If Modifier < 80 then 'Don't go under 80%
Modifier = 80
endif
If Modifier <128 then 'test to see what it thinks
gpio.1 = 1
endif
'Test
'Modifier = 150
ADCON0 = %10000001
'Get the O2 Voltage and repeat infinitely.
GetADC:
x=0 'Re-Set the initial variables and get ADC
adavg = 0
adval= 0
dutycycle1=0
'Read Vin1 Input variable
Repeat
ADCIN 0 , adval 'Read channel 0 to adval
adavg = adavg + adval 'Keep adding readings together
x = x +1 'Increment temporary "x" variable
until x = 31 'Until we add 32 samples
adavg = adavg/32 'Then Average the readings of 32 samples
Vin1 = adavg 'Vin1 becomes the averaged sample (10 bits!)
if Vin1 < 5 then
Vin1=5
endif 'Keeps the math minimums tolerable to division
'CREATE THE DUTY CYCLE
'This math takes the sampled voltage and modifies the sample
'which takes a DIV32 command.
dc1tmp = Vin1 * modifier 'Increase (modify) the "sample" of the V
DutyCycle1 = DIV32 352 'Bring it back to a byte size 0-255
' The discrepancy between this and 400 is experimental
' Trial and error made this correct Voltaqes in reality
'Output a corresponding PWM (modified) relative to the voltage input
'Send Pulse
HPWM 1,DutyCycle1, 20000 'Send PWM at 20K out GPIO.2 (Pin 5)
pause 10 'For some reason, this keep things more stable. No speed issues.
goto GetADC 'Do it forever
I still consider myself new to PicBasic Pro and in fact, to any programming, and I could really use a second set of eyes on this little piece of my project.
I am using a 12f683, a 20 Mhz Oscillator, two separate Pots for ADC input on channel 0 (GP0) and channel 3 (GP4) and the HPWM output (GP2.)
Below is the code, but here is the overall plan:
1st it reads the AN3 pot to get a static variable which will ultimately be a number between 80 and 175. This will not change again while the program is "looping."
Then it gets a varying voltage from AN0. That part works perfectly.
I can't get AN3 to read anything other than 0 even though there is 2V there.
Methinks my setup is wrong but to me, it seems like that is what the data sheet wants. Thanks for any input you have. I really appreciate it. Being a beginner is really HARD.
DEFINE OSC 20 '20 Mhz clock
DEFINE ADC_BITS 10 ' This requires a "Word" variable
DEFINE ADC_CLOCK 3 'Uses internal RC clock
DEFINE ADC_SAMPLEUS 20 'Microsecond sample time
'SETUP
'-------------------------
TRISIO = %00011001 ' AN0 (GPIO.0) and AN3 (GPIO.4) and GPIO.3 inputs
'Analog to Digital Converter Configuration
ANSEL = %00001001 ' Select AN0,3 as analog input (0 Will not work on EasyPIC dev)
ADCON0 = %10001101 ' Right justify result, AN3 selected, ADC On
'-----------------------------------------------------
Pauseus 10
' Delay to allow for VREF to settle
'------------------------------------------------------------------
'#### VARIABLES ######
adval var Word ' Create adval to store result
x var Byte ' "For" temp variable
adavg VAR Word ' Average of the AD input
Modifier VAR Byte 'Modifier value from above A/D conversion
DutyCycle1 VAR WORD 'Duty Cycle 1-255 for HPWM for O2-1
Vin1 Var word
'Temp for DIV32 math
dc1tmp VAR WORD '
'-------------------------------------------------------------------
'Begin the program
x=0 'Re-Set the initial variables and get ADC for modifier value
adavg = 0 '(80%-175%)
adval= 0
'1st get the modifier value
Repeat
ADCIN 3 , adval ' Read channel 3 to adval
adavg = adavg + adval 'Keep adding readings together
x = x +1 'Increment temporary "x" variable
until x = 31 'Until we add 8 samples
adavg = adavg/32 'Then Average the readings of 32 samples
Modifier = adavg/4 'Modifier becomes the averaged sample as 8 bits
if Modifier > 175 then
Modifier = 175 'Don't go over 175%
endif
If Modifier < 80 then 'Don't go under 80%
Modifier = 80
endif
If Modifier <128 then 'test to see what it thinks
gpio.1 = 1
endif
'Test
'Modifier = 150
ADCON0 = %10000001
'Get the O2 Voltage and repeat infinitely.
GetADC:
x=0 'Re-Set the initial variables and get ADC
adavg = 0
adval= 0
dutycycle1=0
'Read Vin1 Input variable
Repeat
ADCIN 0 , adval 'Read channel 0 to adval
adavg = adavg + adval 'Keep adding readings together
x = x +1 'Increment temporary "x" variable
until x = 31 'Until we add 32 samples
adavg = adavg/32 'Then Average the readings of 32 samples
Vin1 = adavg 'Vin1 becomes the averaged sample (10 bits!)
if Vin1 < 5 then
Vin1=5
endif 'Keeps the math minimums tolerable to division
'CREATE THE DUTY CYCLE
'This math takes the sampled voltage and modifies the sample
'which takes a DIV32 command.
dc1tmp = Vin1 * modifier 'Increase (modify) the "sample" of the V
DutyCycle1 = DIV32 352 'Bring it back to a byte size 0-255
' The discrepancy between this and 400 is experimental
' Trial and error made this correct Voltaqes in reality
'Output a corresponding PWM (modified) relative to the voltage input
'Send Pulse
HPWM 1,DutyCycle1, 20000 'Send PWM at 20K out GPIO.2 (Pin 5)
pause 10 'For some reason, this keep things more stable. No speed issues.
goto GetADC 'Do it forever