Changeset 573 for trunk/electronics/avr

Timestamp:

10/15/09 23:45:44 (2 years ago)

Author:

kleinjt

Message:

updated i2c slave code, added distance corrections, eeprom address settings, other fun feature-bloat

Location:

trunk/electronics/avr/i2c_irboard/i2c_slave

Files:

• I2C_Slave.c (modified) (3 diffs)
• I2C_Slave.hex (added)

trunk/electronics/avr/i2c_irboard/i2c_slave/I2C_Slave.c

@@ -32 +32 @@
 
 #include <avr/io.h>
+#include <avr/eeprom.h>
 #include <avr/interrupt.h>
 #include <avr/pgmspace.h>
@@ -39 +40 @@
 #define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
 
+// i2c commands
+#define RAW_ADC         ( 1 )
+#define DISTANCE        ( 2 )
+#define SETADDR         ( 3 )
+#define READADDR        ( 4 )
+#define SET_CORR        ( 5 )
+#define ERROR           ( 0 ) 
+
 uint16_t ADCIN(void);
-uint16_t value;
-uint16_t analog;
+uint8_t EEMEM slaveaddr = 0x26;
+uint16_t EEMEM EE_m = 6787;
+uint8_t EEMEM EE_b = 3;
+uint8_t EEMEM EE_k = 4;
 
-
-/* Brief: This section determines what format to return the value in. */
-
-enum { DATA1, DATA2, RAW };
-
-//-----------------------------------------------------------------------------
-
-/* This section allows you to select between three different modes. In this sample
-each return the value of the analog at different levels just to give an idea of how
-it can be used. */
-
-void mode(uint8_t mode, uint8_t on)
-{
-  analog = ADCIN();
-  switch (mode)
-  {
-    case DATA1: if (on) (value = analog * 2); break;
-    case DATA2: if (on) (value = analog / 10); break;
-    case RAW:   if (on) (value = analog); break;
-  }
+uint8_t distance(uint16_t k, uint8_t m, uint8_t b) {
+  uint16_t analog = ADCIN();
+  uint16_t distance = (m / (analog - b)) - k;
+  if(distance > 255) distance = 255;
+  if(distance < 0) distance = 0;
+  // http://www.acroname.com/robotics/info/articles/irlinear/irlinear.html 
+  return analog;
 }
 
-/* Brief: The main function.
- * The program entry point. Initates TWI and enters eternal loop, waiting for data.
- */
 int main(void)
 {
-  unsigned char slaveAddress, temp;
-
+  uint8_t temp;
+  uint16_t value;
   sei();
 
@@ -83 +78 @@
         cbi(DDRB, DDB1);        // pb1 set up as input
         cbi(DDRB, DDB3);        // pb3 set up as input
-//   cbi(DDRB, DDB5);           // pb5 set up as input (use only in production, wipes out reset pin)
         sbi(PORTB, PB1);                // Set pb1 internal pullup
         sbi(PORTB, PB3);                // Set pb3 internal pullup
-//       sbi(PORTB, PB5);               // (use only in production, wipes out reset pin)
-
-  slaveAddress = 0x26;          // This can be change to your own address
 
 
-  usiTwiSlaveInit(slaveAddress);
+  uint16_t m = eeprom_read_word(&EE_m);  
+  uint8_t b = eeprom_read_byte(&EE_b);
+  uint8_t k = eeprom_read_byte(&EE_k);
 
-  // This loop runs forever. If the TWI Transceiver is busy the execution will
-  // just continue doing other operations.
+  usiTwiSlaveInit(eeprom_read_byte(&slaveaddr));
+
   for(;;)
   {
-
-
     if(usiTwiDataInReceiveBuffer())
     {
+     value = 1;
          temp = usiTwiReceiveByte();
       switch (temp)
-       {
-           case 1: mode(DATA1, 1);   break;             // the case is selected by a single
-       case 2: mode(DATA2, 1);   break;         // digit in the master code. (1,2 or 3)
-       case 3: mode(RAW, 1);     break;
-       }
+      {
+           case RAW_ADC:
+             value = ADCIN() << 2;
+             break;
+       case SETADDR:
+         eeprom_write_byte(&slaveaddr, usiTwiReceiveByte());
+         value = eeprom_read_byte(&slaveaddr);
+         break;
+       case DISTANCE:
+         value = distance(k, m, b);
+         break;
+       case READADDR:
+         value = eeprom_read_byte(&slaveaddr);      
+         break;
+       case SET_CORR:
+         while(!usiTwiDataInReceiveBuffer());
+         m = usiTwiReceiveByte();
+         m = m << 8;
+         while(!usiTwiDataInReceiveBuffer());
+         m = m | usiTwiReceiveByte();
+         eeprom_write_word(&EE_m, m);
+         while(!usiTwiDataInReceiveBuffer());
+         b = usiTwiReceiveByte();
+         eeprom_write_byte(&EE_b, b);
+         while(!usiTwiDataInReceiveBuffer());
+         k = usiTwiReceiveByte();
+         eeprom_write_byte(&EE_k, k);
+       default:
+         value = ERROR;
+         break;
+      }
 
      usiTwiTransmitByte(value);
     }
 
-    // Do something else while waiting for the TWI transceiver to complete.
+    asm volatile ("NOP" ::); // stall while waiting for the TWI transceiver to complete
 
-    asm volatile ("NOP" ::);
   }
 }
-
-/*
- *  ADCIN
- *
- *  Read the specified Analog to Digital Conversion channel
- *
- */
 
 uint16_t ADCIN(void)