0,0 → 1,193 |
// ************************************************************ |
// ** Spektrum Diversity - use up to 8 satellite receivers ** |
// ************************************************************ |
// ** Target: An Atmel ATtiny2313 (RC-Oscillator @ 8 MHz) ** |
// ** controls a 74HC151 Multiplexer ** |
// ************************************************************ |
// ** It monitors the data from 8 satellite receivers and ** |
// ** connects a valid one to the output via the multiplexer ** |
// ************************************************************ |
// ** LED-Modes during startup (in chronological order) ** |
// ** ************************ ** |
// ** LED fast blink: Waiting for first datapulse ** |
// ** LED slow blink: Waiting 3 seconds while counting sat's ** |
// ** LED flashes: Indicates the number of active sat's ** |
// ** ** |
// ** LED-Modes during operation ** |
// ** ************************** ** |
// ** LED OFF: Everything is fine ** |
// ** LED ON: FAILURE - The first selected sat had lost sync ** |
// ************************************************************ |
// ** (c) 2010-0xFFFF Stefan Pendsa ** |
// ** License: don't know - use it and have fun ** |
// ************************************************************ |
|
#include <avr/io.h> |
#include <avr/interrupt.h> |
#include <util/delay.h> |
|
#define LED_OFF PORTD |= 1 << PORTD3 |
#define LED_ON PORTD &= ~(1 << PORTD3) |
|
|
volatile unsigned int TimerEvent; |
|
|
void SelectSat(unsigned char sat) |
{ |
/* |
Re-Assignment due to easier routing on layout: sat -> mux-channel# -> mux-input (seen from µC) |
0 -> 2 -> 2 |
1 -> 1 -> 4 |
2 -> 0 -> 0 |
3 -> 3 -> 6 |
4 -> 4 -> 1 |
5 -> 5 -> 5 |
6 -> 6 -> 3 |
7 -> 7 -> 7 |
*/ |
|
|
if (sat == 0) sat = 2; |
else if (sat == 1) sat = 4; |
else if (sat == 2) sat = 0; |
else if (sat == 3) sat = 6; |
else if (sat == 4) sat = 1; |
else if (sat == 5) sat = 5; |
else if (sat == 6) sat = 3; |
else if (sat == 7) sat = 7; |
|
|
PORTD = (PORTD & 0b00001000) | sat; |
} |
|
void ResetTimer(void) |
{ |
TCNT1H = 0; |
TCNT1L = 0; |
TimerEvent = 0; |
} |
|
|
|
ISR(TIMER1_OVF_vect) // Triggered every 4,096 msec |
{ |
TimerEvent++; |
} |
|
|
int main(void) |
{ |
unsigned char i = 0; |
unsigned int j = 0; |
unsigned char active[8]; |
unsigned char sat = 9; |
DDRB = 0b00000000; // PORT A INPUT FOR SATELLITES |
DDRD = 0b00001111; // PORT B OUTPUT FOR MUX AND LED |
PORTB = 0b11111111; // PORT A PULLUP's FOR (unused) SATELLITES |
|
|
TCCR1B = ( 1 << CS10 ); // Timer1 Prescaler 1 = 4,096 msec |
TIMSK = ( 1 << TOIE1 ); // Timer1 Overflow Interrupt Enable |
sei(); // Global Interrupts enable |
|
for (i=0;i<8;i++) active[i] = 0; // Reset active-array |
|
ResetTimer(); |
while(PINB == 255) // Wait for first signal (SYNC to frame) |
{ |
if (TimerEvent == 10) LED_ON; // Blink while waiting... |
if (TimerEvent == 20) |
{ |
LED_OFF; |
TimerEvent = 0; |
} |
} |
|
LED_OFF; |
|
ResetTimer(); |
while(1) // Check active satellites for 3 seconds |
{ |
if (TimerEvent == 20) LED_ON; // Blink (slower) while waiting... |
if (TimerEvent == 40) |
{ |
LED_OFF; |
TimerEvent = 0; |
j++; |
} |
|
for (i=0;i<8;i++) |
{ |
if (!(PINB & (1<<i))) |
{ |
active[i] = 1; |
if (sat == 9) // Select first active satellite (only once) |
{ |
sat = i; |
SelectSat(i); |
} |
|
} |
} |
|
if (j == 9) break; // 9 * 40 * 8ms = ~3sec |
} |
|
LED_OFF; |
_delay_ms(1000); |
|
for (i=0;i<8;i++) // Flash once for every active satellite |
{ |
if (active[i] == 1) |
{ |
LED_ON; |
_delay_ms(200); |
LED_OFF; |
_delay_ms(200); |
} |
} |
|
|
|
|
while(1) // Main-Loop |
{ |
ResetTimer(); |
|
while(PINB == 255) // Wait for first signal (SYNC to frame) |
{ |
if (TimerEvent > 3) break; // (max. 3*8=24ms) |
} |
|
for (i=0;i<8;i++) active[i] = 0; // Reset active-array |
ResetTimer(); |
|
while(TimerEvent < 1) // Check active satellites (for 1*8=8ms) |
{ |
|
for (i=0;i<8;i++) |
{ |
if (!(PINB & (1<<i))) |
{ |
active[i] = 1; |
} |
} |
} |
|
|
if (active[sat] == 0) // Detect fail on active satellite |
{ |
LED_ON; // Failure-LED ON (never goes off again) |
for (i=0;i<8;i++) // Select lowest active satellite |
{ |
if (active[i] == 1) |
{ |
sat = i; |
SelectSat(sat); |
break; |
} |
} |
} |
} |
} |