Starting up the ADC ATmega32U4!

[Winch]

Hi,
Never worked with an ATmega32U4 before, until now worked with PIC processors!
Try to start the ADC but it seems to be different from a PIC? What is wrong with the bottom code?
The LCD display shows the maximum information from the ADC. (1023)
A potentiometer is connected to the input, but the ADC input does not respond to this.
When I use such a code with a PIC it doesn't cause any problems.

'device ATmega32u4

Define CLOCK_FREQUENCY = 16

Define LCD_BITS = 4
Define LCD_DREG = PORTB
Define LCD_DBIT = 4
Define LCD_RSREG = PORTD
Define LCD_RSBIT = 4
Define LCD_EREG = PORTD
Define LCD_EBIT = 7
Define LCD_RWREG = PORTD
Define LCD_RWBIT = 0

Define ADC_CLOCK = 3
Define ADC_VREF = 0
Define ADC_SAMPLEUS = 20

ConfigPin PORTF.5 = Input

Dim pot As Word

Lcdinit 0
WaitMs 500

pot = 0

main:

        Adcin 5, pot
        Lcdcmdout LcdLine1Home
        Lcdout "Potentiometer"
        Lcdcmdout LcdLine2Home
        Lcdout #pot
        WaitMs 100
       
Goto main
End

 

[Ian Rogers]

Portf.5 is also the TMS pin You need to reset the fuse for the JTAGEN to disable it ( 0 ) .... I get that on the pic32... Piggin annoying..

 

[Winch]

No, I tried with the code below.
I've added the "MCUCR" MCU control register
but without result.
Meanwhile, I tried another port the "ADCin 1" still the same problem.

Now I am unsure whether Oshonsoft supports the ADC of the ATmega32U4 with the AVR Basic compiler?
I have the version AVR Basic Compiler v2.85 it is the latest version that I know for sure.

'device ATmega32u4

Define CLOCK_FREQUENCY = 16

Define LCD_BITS = 4
Define LCD_DREG = PORTB
Define LCD_DBIT = 4
Define LCD_RSREG = PORTD
Define LCD_RSBIT = 4
Define LCD_EREG = PORTD
Define LCD_EBIT = 7
Define LCD_RWREG = PORTD
Define LCD_RWBIT = 0

Define ADC_CLOCK = 3
Define ADC_VREF = 0
Define ADC_SAMPLEUS = 20

MCUCR = %00000000

DDRF.1 = 0  'input

Dim pot As Word

Lcdinit 0
WaitMs 500

pot = 0
A = 0

main:
        Adcin 1, pot
        Lcdcmdout LcdLine1Home
        Lcdout "Potentiometer"
        Lcdcmdout LcdLine2Home
        Lcdout #pot
        WaitMs 100

Goto main
End

 

[Ian Rogers]

The oshonsoft ide has a config settings... You need to edit them.. The IDE said it supports that chip fully... I can help any more than that as I use Pic's and I'm not buying stuff just for this..

I can write code to suit but I cannot test it..

 

[Winch]

You mean the "configurations bits" under "environment" in the PIC compiler.
These are not present in the AVR! So we have to figure this out yourself in the AVR environment.

 

[Ian Rogers]

Yup...After re-reading Adcin used with just 5 will read singe ended channel.. But it looks like the default reference is the Aref pin so you may need to attach it to Vcc ( pin 42 ) The MUX register will allow channel + ref + justification.. At the very least the AREF pin need a cap on it..

 

[Winch]

Oke,
Small step further today.
The arduino board has the AREF pin with a 100n to the ground as standard.
And the AVCC is connected with a coil and a capacitor according the specification of the datasheet ATmega32U4.

With this in mind, the following setting has been chosen in the ADMUX register REFS1 = 0 and REFS0 = 1.
All according to the datasheet.

With the result that there is now a visible measure on the display.
Only not stable, it slowly increases to 1023?

Still searching but with a little result, If there are any good ideas please!

'Hardware comes from the Arduino Leonardo PCB
'device ATmega32u4

Define CLOCK_FREQUENCY = 16

Define LCD_BITS = 4
Define LCD_DREG = PORTB
Define LCD_DBIT = 4
Define LCD_RSREG = PORTD
Define LCD_RSBIT = 4
Define LCD_EREG = PORTD
Define LCD_EBIT = 7
Define LCD_RWREG = PORTD
Define LCD_RWBIT = 0

Define ADC_SAMPLEUS = 20
Define ADC_CLOCK = 3
Define ADC_VREF = 0

'MCUCR = %00010000

ADCSRA.ADEN = 1  'Writing this bit to one enables the ADC

'ADMUX = ADC Multiplexer selection register
ADMUX.REFS1 = 0  'AVcc with external capacitor on AREF pin as it is on the Leonardo board
ADMUX.REFS0 = 1  '"
ADMUX.ADLAR = 0  'set to 1 = ADC Left Adjust Result
ADMUX.MUX4 = 0  'Analog channel selection bits in this case Port5
ADMUX.MUX3 = 0  '"
ADMUX.MUX2 = 1  '"
ADMUX.MUX1 = 0  '"
ADMUX.MUX0 = 1  '"

DDRF.5 = 0  'input ADC5, input PF5

Dim pot As Word

Lcdinit 0
WaitMs 500

pot = 0

main:
    
    Adcin 5, pot
        Lcdcmdout LcdLine1Home
        Lcdout "Potentiometer"
        Lcdcmdout LcdLine2Home
        Lcdout #pot
        WaitMs 100

Goto main
End

 

[Winch]

Hi,
It turned out to be the define settings of the ADC that were wrong.
And especially the ADC_VREF setting.
Now it works fine.

'****************************************************************
'* Hardware version  : Hardware = Arduino Leonardo PCB
'* Firmware-version  : Beta (version 1.0)
'* Microcontroller   : ATmega32U4
'* Notes             :
'*
'****************************************************************

Define CLOCK_FREQUENCY = 16

Define LCD_BITS = 4
Define LCD_DREG = PORTB
Define LCD_DBIT = 4
Define LCD_RSREG = PORTD
Define LCD_RSBIT = 4
Define LCD_EREG = PORTD
Define LCD_EBIT = 7
Define LCD_RWREG = PORTD
Define LCD_RWBIT = 0

Define ADC_SAMPLEUS = 20
Define ADC_CLOCK = 7  'ADC input Prescaler Selections = 128
Define ADC_VREF = 1  'AVCC with external capacitor on AREF pin

DDRD.3 = 1  'output
DDRF.1 = 0  'input ADC1, input PF1

Dim pot As Word

Lcdinit 0
WaitMs 500

pot = 0

main:

    Adcin 1, pot
    
        Lcdcmdout LcdLine1Home
        Lcdout "Potentiometer"
        Lcdcmdout LcdLine2Home
        Lcdout #pot
        WaitMs 200
        
Goto main
End