You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
77 lines
1.5 KiB
77 lines
1.5 KiB
/* |
|
ADS7844 register emulation |
|
Code by Andrew Tridgell November 2011 |
|
*/ |
|
|
|
#ifndef _SITL_ADC_H |
|
#define _SITL_ADC_H |
|
|
|
#include <stdlib.h> |
|
|
|
// this implements the UDR2 register |
|
struct ADC_UDR2 { |
|
uint16_t value, next_value; |
|
uint8_t idx; |
|
float channels[8]; |
|
|
|
ADC_UDR2() { |
|
// constructor |
|
for (uint8_t i=0; i<8; i++) { |
|
channels[i] = 0xFFFF; |
|
} |
|
value = next_value = 0; |
|
idx = 0; |
|
} |
|
|
|
/* |
|
assignment of UDR2 selects which ADC channel |
|
to output next |
|
*/ |
|
ADC_UDR2& operator=(uint8_t cmd) { |
|
float next_analog; |
|
switch (cmd) { |
|
case 0x87: next_analog = channels[0]; break; |
|
case 0xC7: next_analog = channels[1]; break; |
|
case 0x97: next_analog = channels[2]; break; |
|
case 0xD7: next_analog = channels[3]; break; |
|
case 0xA7: next_analog = channels[4]; break; |
|
case 0xE7: next_analog = channels[5]; break; |
|
case 0xB7: next_analog = channels[6]; break; |
|
case 0xF7: next_analog = channels[7]; break; |
|
case 0: |
|
default: return *this; |
|
} |
|
idx = 1; |
|
int noise = (((unsigned long)random()) % 3) - 1; |
|
next_value = (unsigned)(next_analog + noise + 0.5); |
|
if (next_value >= 0x1000) { |
|
next_value = 0xFFF; |
|
} |
|
next_value = (next_value << 3); |
|
return *this; |
|
} |
|
|
|
/* |
|
read from UDR2 fetches a byte from the channel |
|
*/ |
|
operator int() { |
|
uint8_t ret; |
|
if (idx & 1) { |
|
ret = (value&0xFF); |
|
value = next_value; |
|
} else { |
|
ret = (value>>8); |
|
} |
|
idx ^= 1; |
|
return ret; |
|
} |
|
|
|
/* |
|
interface to set a channel value from SITL |
|
*/ |
|
void set(uint8_t i, float v) { |
|
channels[i] = v; |
|
} |
|
}; |
|
|
|
#endif // _SITL_ADC_H
|
|
|