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Changes to fix the real-10-bit case.

git-svn-id: https://bucket.mit.edu/svn/nilm/zoom@9082 ddd99763-3ecb-0310-9145-efcb8ce7c51f
tags/zoom-1.0
jim 11 years ago
parent
commit
6b5a14b01f
4 changed files with 41 additions and 17 deletions
  1. +19
    -6
      firmware/dac.c
  2. +21
    -10
      firmware/dac.h
  3. +1
    -1
      firmware/mode_debug.c
  4. BIN
      firmware/zoom.mcw

+ 19
- 6
firmware/dac.c View File

@@ -43,22 +43,35 @@ void dac_write(uint16_t val)
{
LATGbits.LATG9 = IO_LOW;
if (IO_HIGH == 1)
SPI2BUF = __dac_actual(val);
SPI2BUF = __dac_to_spi_cmd(val);
else
SPI2BUF = ~__dac_actual(val);
SPI2BUF = ~__dac_to_spi_cmd(val);
while (!SPI2STATbits.SPIRBF)
continue;
(void) SPI2BUF;
LATGbits.LATG9 = IO_HIGH;
}
uint16_t dac_get_actual(uint16_t val)
/* Given a DAC command between DAC_LOW and DAC_HIGH,
get the actual expected output voltage as a 16-bit value, where:
0xffff = 4.9998v
0x8000 = 0v
0x0000 = -5v
*/
uint16_t dac_get_actual_16bit(uint16_t val)
{
return __dac_actual(val);
return __dac_to_16bit_equiv(val);
}
/* Get actual output voltage from DAC_LOW to DAC_HIGH, as a float */
/* Given a DAC command between DAC_LOW and DAC_HIGH,
get the actual expected output voltage as a FLOAT, where:
DAC_HIGH = 4.9998v
DAC_MID = 0v
DAC_LOW = -5v
Example: for 10-bit DAC, convert integer command 123 into
the more accurate 123.45 using known lower bits.
*/
float dac_get_actual_float(uint16_t val)
{
return __dac_actual(val) * (DAC_RANGE / 65536.0);
return __dac_to_16bit_equiv(val) * (DAC_RANGE / 65536.0);
}

+ 21
- 10
firmware/dac.h View File

@@ -8,15 +8,18 @@
#if DAC_TYPE == 0
/* AD5542, normal 16-bit range */
#define DAC_BITS 16
#define __dac_actual(x) (x)
#define __dac_to_spi_cmd(x) (x)
#define __dac_to_16bit_equiv(x) (x)
#elif DAC_TYPE == 1
/* AD5542, fake 10-bit range using random lower bits */
#define DAC_BITS 10
#define __dac_actual(x) (dac_lookup[(x)&1023])
#define __dac_to_spi_cmd(x) (dac_lookup[(x)&1023])
#define __dac_to_16bit_equiv(x) (dac_lookup[(x)&1023])
#elif DAC_TYPE == 2
/* MAX504, true 10-bit DAC */
#define DAC_BITS 10
#define __dac_actual(x) ((x) << 2)
#define __dac_to_spi_cmd(x) ((x) << 2)
#define __dac_to_16bit_equiv(x) ((x) << 6)
#else
#error Unknown DAC type
#endif
@@ -36,14 +39,22 @@ void dac_init(void);
*/
void dac_write(uint16_t val);
/* From DAC value, get the expected actual output voltage:
0xffff 4.9998v
0x8000 0v
0x0000 -5v
/* Given a DAC command between DAC_LOW and DAC_HIGH,
get the actual expected output voltage as a 16-bit value, where:
0xffff = 4.9998v
0x8000 = 0v
0x0000 = -5v
*/
uint16_t dac_get_actual_16bit(uint16_t val);
/* Given a DAC command between DAC_LOW and DAC_HIGH,
get the actual expected output voltage as a FLOAT, where:
DAC_HIGH = 4.9998v
DAC_MID = 0v
DAC_LOW = -5v
Example: for 10-bit DAC, convert integer command 123 into
the more accurate 123.45 using known lower bits.
*/
uint16_t dac_get_actual(uint16_t val);
/* Get actual output voltage from DAC_LOW to DAC_HIGH, as a float */
float dac_get_actual_float(uint16_t val);
#endif

+ 1
- 1
firmware/mode_debug.c View File

@@ -58,7 +58,7 @@ void run_debug(void)
dac_write(dac);
uart1_put_hex16(dac);
uart1_put(' ');
uart1_put_dec(dac_get_actual(dac));
uart1_put_dec(dac_get_actual_16bit(dac));
uart1_put(' ');
uart1_put(' ');
adc = adc_get();


BIN
firmware/zoom.mcw View File


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