Usart + Adc - Electronic Circuits Projects Diagrams Free

Overclocked · 26th January 2009, 06:14 PM

Ive gotten the ADC to work to control the blink rate of a LED, but now I want to try and read the ADC value via USART on my Junebug. Ive gotten it to "talk" with the computer, but It gives me Funky stuff (numbers/letters/symbols) instead of the values I want. Im using a PIC18F1320 and using the pots on the junebug as my voltage source for the ADC.

Code:

Device = 18F1320
Clock = 4 // 4MHz clock
Config OSC = INTIO2, WDT = OFF, LVP = OFF

Include "IntOsc4.bas"
Include "ADC.bas"
Include "USART.bas"
Include "convert.bas"

    
Function Get_ADC_Sample() As Float   // Function to grab the ADC sample

    result = ADC.Read(1)     //grab a voltage from channel 1 and convert it
    result = (result +1)*500
    result = result / 1024
End Function

SetBaudrate (br9600)

   
While True                         // Create an infinite loop
USART.Write ("DC Volts = ",Get_ADC_Sample ,13,10)
DelayMS (500)
        
Wend

Note "IntOsc4.bas" is the basic file for the internal osc running at 4Mhz

blueroomelectronics · 26th January 2009, 06:44 PM

Did you try the AD logger program in JPUG#2?

Overclocked · 28th January 2009, 05:04 PM

Quote:

Originally Posted by blueroomelectronics

Did you try the AD logger program in JPUG#2?

Yes, but why not use adc.bas rather than setting up the AD converter "manually"?

**Nigel Goodwin** · 28th January 2009, 05:19 PM

Quote:

Originally Posted by Overclocked

Yes, but why not use adc.bas rather than setting up the AD converter "manually"?

Because you might learn what you're doing?.

blueroomelectronics · 28th January 2009, 05:22 PM

I've edited Gramo's ADC code to get it working with the Junebug.
Spency's digital-diy 18F PIC micro Tutorial - ADC

PS I think the problem with your program has to do with float vs integer math. I've found myself having all sorts of weird results until I make sure all my variables are of the same type.

Code:

Device = 18F1320
Clock = 4
Config OSC = INTIO2, WDT = OFF, LVP = OFF

Include "USART.bas"
Include "ADC.bas"
Include "convert.bas"

Dim ADVal As Word
// Read the AD port and scale for 0.00 - 5.00 volts...
Function ADInAsVolt() As Word
    result = (ADC.Read(1) + 1) * 500 / 1024
End Function
// Start Of Program...
OSCCON = $62    ' 4MHz internal clock
SetBaudrate (br9600)

// main program loop...
While true
    ADVal = ADInAsVolt
    USART.Write("DC Volts = ", DecToStr(ADVal / 100), ".", DecToStr(ADVal, 2), " ",13,10)
    DelayMS(500)
Wend

Overclocked · 28th January 2009, 06:35 PM

Quote:

Originally Posted by blueroomelectronics

I've edited Gramo's ADC code to get it working with the Junebug.
Spency's digital-diy 18F PIC micro Tutorial - ADC

PS I think the problem with your program has to do with float vs integer math. I've found myself having all sorts of weird results until I make sure all my variables are of the same type.

Awesome, that works. Thanks =D

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26th January 2009, 06:14 PM	#1
Overclocked	Usart + Adc Ive gotten the ADC to work to control the blink rate of a LED, but now I want to try and read the ADC value via USART on my Junebug. Ive gotten it to "talk" with the computer, but It gives me Funky stuff (numbers/letters/symbols) instead of the values I want. Im using a PIC18F1320 and using the pots on the junebug as my voltage source for the ADC. Code: Device = 18F1320 Clock = 4 // 4MHz clock Config OSC = INTIO2, WDT = OFF, LVP = OFF Include "IntOsc4.bas" Include "ADC.bas" Include "USART.bas" Include "convert.bas" Function Get_ADC_Sample() As Float // Function to grab the ADC sample result = ADC.Read(1) //grab a voltage from channel 1 and convert it result = (result +1)*500 result = result / 1024 End Function SetBaudrate (br9600) While True // Create an infinite loop USART.Write ("DC Volts = ",Get_ADC_Sample ,13,10) DelayMS (500) Wend Note "IntOsc4.bas" is the basic file for the internal osc running at 4Mhz __________________ I believe that you're wrong. Insinuating that they hold the bomb. ---

26th January 2009, 06:44 PM	#2
blueroomelectronics	Did you try the AD logger program in JPUG#2? __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com/

28th January 2009, 05:22 PM	#5
blueroomelectronics	I've edited Gramo's ADC code to get it working with the Junebug. Spency's digital-diy 18F PIC micro Tutorial - ADC PS I think the problem with your program has to do with float vs integer math. I've found myself having all sorts of weird results until I make sure all my variables are of the same type. Code: Device = 18F1320 Clock = 4 Config OSC = INTIO2, WDT = OFF, LVP = OFF Include "USART.bas" Include "ADC.bas" Include "convert.bas" Dim ADVal As Word // Read the AD port and scale for 0.00 - 5.00 volts... Function ADInAsVolt() As Word result = (ADC.Read(1) + 1) * 500 / 1024 End Function // Start Of Program... OSCCON = $62 ' 4MHz internal clock SetBaudrate (br9600) // main program loop... While true ADVal = ADInAsVolt USART.Write("DC Volts = ", DecToStr(ADVal / 100), ".", DecToStr(ADVal, 2), " ",13,10) DelayMS(500) Wend __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com/ Last edited by blueroomelectronics; 28th January 2009 at 05:24 PM.