Trouble with ADC0831

Derek Brown

Hey,

I'm trying to use an ADC0831CCN with my BS2 and a TSL257T but I'm getting nothing but all 00000000 when I run my program. I've never worked with these before and I am using the example program from the A/D book. I'm pretty sure that wired everything up right but I just cannot get any kind of reading from it. I even tried setting upa test circuit with a 10k pot and still no dice. I replaced the chip since I bought two and still nothing. Any ideas on what I may be doing wrong?


Here is that program.

'

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[noparse][[/noparse] Title ]

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' Basic Analog and Digital - PL3_1R0.bs2
' Program Listing 3.1 Revision 0.
' {$STAMP BS2}
' {$PBASIC 2.5}

'

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[noparse][[/noparse] Declarations ]

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adcBits VAR Word
v VAR Byte
r VAR Byte
v2 VAR Byte
v3 VAR Byte

'

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[noparse][[/noparse] Initialization ]

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CS PIN 0
CLK PIN 1
DataOutput PIN 2

DEBUG CLS 'Start display.

'

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[noparse][[/noparse] Main Routine ]

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DO
GOSUB ADC_Data
GOSUB Calc_Volts
GOSUB Display
LOOP

'

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[noparse][[/noparse] Subroutines ]

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ADC_Data:
LOW CLK
LOW CS
PULSOUT CLK, 210
SHIFTIN DataOutput,CLK,MSBPOST,[noparse][[/noparse]adcBits]
HIGH CS
RETURN

Calc_Volts:
RETURN

Display:
DEBUG HOME
DEBUG "8-bit binary value: ", BIN8 adcBits
RETURN


NOTE: ADC pin arrangement

1) P0
2) input from pot/TSL
3) Vss
4) Vss
5) Vdd
6) P2
7) P1
8) Vdd


Thanks,

Derek

Franklin

Start by running the example code that reads the pin the ADC is attached to then take a wire with a 330 ohm resistor in series and touch it between the pin and ground, then the pin and 5v. You should get 0 and 1023. If not go back and check your connections, follow the drawings in the documentation.

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- Stephen