61 lines
1.5 KiB
C
61 lines
1.5 KiB
C
#ifndef DAC_H
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#define DAC_H
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#include "config.h"
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#define DAC_TYPE 2
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#if DAC_TYPE == 0
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/* AD5542, normal 16-bit range */
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#define DAC_BITS 16
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#define __dac_to_spi_cmd(x) (x)
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#define __dac_to_16bit_equiv(x) (x)
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#elif DAC_TYPE == 1
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/* AD5542, fake 10-bit range using random lower bits */
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#define DAC_BITS 10
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#define __dac_to_spi_cmd(x) (dac_lookup[(x)&1023])
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#define __dac_to_16bit_equiv(x) (dac_lookup[(x)&1023])
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#elif DAC_TYPE == 2
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/* MAX504, true 10-bit DAC */
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#define DAC_BITS 10
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#define __dac_to_spi_cmd(x) ((x) << 2)
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#define __dac_to_16bit_equiv(x) ((x) << 6)
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#else
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#error Unknown DAC type
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#endif
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#define DAC_LOW 0
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#define DAC_HIGH ((uint16_t)(((uint32_t)1 << DAC_BITS) - 1))
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#define DAC_MID ((uint16_t)((DAC_LOW + DAC_HIGH + (uint32_t)1) / 2))
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#define DAC_RANGE (DAC_HIGH - DAC_LOW + 1)
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/* Initialize DAC (AD5542) */
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void dac_init(void);
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/* Write raw value to DAC:
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DAC_HIGH 4.9998v
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DAC_MID 0v
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DAC_LOW -5v
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*/
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void dac_write(uint16_t val);
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/* Given a DAC command between DAC_LOW and DAC_HIGH,
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get the actual expected output voltage as a 16-bit value, where:
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0xffff = 4.9998v
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0x8000 = 0v
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0x0000 = -5v
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*/
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uint16_t dac_get_actual_16bit(uint16_t val);
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/* Given a DAC command between DAC_LOW and DAC_HIGH,
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get the actual expected output voltage as a FLOAT, where:
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DAC_HIGH = 4.9998v
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DAC_MID = 0v
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DAC_LOW = -5v
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Example: for 10-bit DAC, convert integer command 123 into
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the more accurate 123.45 using known lower bits.
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*/
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float dac_get_actual_float(uint16_t val);
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#endif
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