SHIVA T
this is a small prototype for color sensor, which can detect three colors... this was made by using an LDR,1.5 K resistor and the wiz wiki 7500 board
Fork of
ADC_test
by 
Simon Blandford
the things you need for this are wiznet board or any other micro controller can do it when you understand the logic i have applied here.An LDR and one resistor for your reference i have used 1.5K resistor in my work.
connect the LDR and resistor in series in between the 3.3V and GND of the board.take outpt from the point where LDR and resistor met.
it's just an voltage divider circuit depends on the color you subject to LDR the resistance of LDR will vary and the volatge also does the same.
then feed the output on the adc pin of micro controller, then you will get various values for various colors. the adc which i have used is 12 bit one that's why it's having 4096 count. you have to change the values in the program according to your adc count.
sorry for my bad english.........
Diff: ADC_full/adc.h
- Revision:
- 1:c88c8173b9b2
- Parent:
- 0:a2562dfbf543
diff -r a2562dfbf543 -r c88c8173b9b2 ADC_full/adc.h
--- a/ADC_full/adc.h Wed Feb 10 13:11:26 2010 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,131 +0,0 @@
-/* mbed Library - ADC
- * Copyright (c) 2010, sblandford
- * released under MIT license http://mbed.org/licence/mit
- */
-
-#ifndef MBED_ADC_H
-#define MBED_ADC_H
-
-#include "mbed.h"
-#define XTAL_FREQ 12000000
-#define MAX_ADC_CLOCK 13000000
-#define CLKS_PER_SAMPLE 64
-
-class ADC {
-public:
-
- //Initialize ADC with ADC maximum sample rate of
- //sample_rate and system clock divider of cclk_div
- //Maximum recommened sample rate is 184000
- ADC(int sample_rate, int cclk_div);
-
- //Enable/disable ADC on pin according to state
- //and also select/de-select for next conversion
- void setup(PinName pin, int state);
-
- //Return enabled/disabled state of ADC on pin
- int setup(PinName pin);
-
- //Enable/disable burst mode according to state
- void burst(int state);
-
- //Select channel already setup
- void select(PinName pin);
-
- //Return burst mode enabled/disabled
- int burst(void);
-
- /*Set start condition and edge according to mode:
- 0 - No start (this value should be used when clearing PDN to 0).
- 1 - Start conversion now.
- 2 - Start conversion when the edge selected by bit 27 occurs on the P2.10 / EINT0 / NMI pin.
- 3 - Start conversion when the edge selected by bit 27 occurs on the P1.27 / CLKOUT /
- USB_OVRCRn / CAP0.1 pin.
- 4 - Start conversion when the edge selected by bit 27 occurs on MAT0.1. Note that this does
- not require that the MAT0.1 function appear on a device pin.
- 5 - Start conversion when the edge selected by bit 27 occurs on MAT0.3. Note that it is not
- possible to cause the MAT0.3 function to appear on a device pin.
- 6 - Start conversion when the edge selected by bit 27 occurs on MAT1.0. Note that this does
- not require that the MAT1.0 function appear on a device pin.
- 7 - Start conversion when the edge selected by bit 27 occurs on MAT1.1. Note that this does
- not require that the MAT1.1 function appear on a device pin.
- When mode >= 2, conversion is triggered by edge:
- 0 - Rising edge
- 1 - Falling edge
- */
- void startmode(int mode, int edge);
-
- //Return startmode state according to mode_edge=0: mode and mode_edge=1: edge
- int startmode(int mode_edge);
-
- //Start ADC conversion
- void start(void);
-
- //Set interrupt enable/disable for pin to state
- void interrupt_state(PinName pin, int state);
-
- //Return enable/disable state of interrupt for pin
- int interrupt_state(PinName pin);
-
- //Attach custom interrupt handler replacing default
- void attach(void(*fptr)(void));
-
- //Restore default interrupt handler
- void detach(void);
-
- //Append custom interrupt handler for pin
- void append(PinName pin, void(*fptr)(uint32_t value));
-
- //Unappend custom interrupt handler for pin
- void unappend(PinName pin);
-
- //Append custom global interrupt handler
- void append(void(*fptr)(int chan, uint32_t value));
-
- //Unappend custom global interrupt handler
- void unappend(void);
-
- //Set ADC offset to a value 0-7
- void offset(int offset);
-
- //Return current ADC offset
- int offset(void);
-
- //Return value of ADC on pin
- int read(PinName pin);
-
- //Return DONE flag of ADC on pin
- int done(PinName pin);
-
- //Return OVERRUN flag of ADC on pin
- int overrun(PinName pin);
-
- //Return actual ADC clock
- int actual_adc_clock(void);
-
- //Return actual maximum sample rate
- int actual_sample_rate(void);
-
- //Return pin ID of ADC channel
- PinName channel_to_pin(int chan);
-
- //Return pin number of ADC channel
- int channel_to_pin_number(int chan);
-
-
-private:
- int _pin_to_channel(PinName pin);
- uint32_t _data_of_pin(PinName pin);
-
- int _adc_clk_freq;
- void adcisr(void);
- static void _adcisr(void);
- static ADC *instance;
-
- uint32_t _adc_data[8];
- void(*_adc_isr[8])(uint32_t value);
- void(*_adc_g_isr)(int chan, uint32_t value);
- void(*_adc_m_isr)(void);
-};
-
-#endif
\ No newline at end of file