Command handing works!

The command handler can now receive a command, then it can run a
function / return some data based on it.

prosjekt.X/command-handler.c

@@ -1,9 +1,10 @@
 #include "command-handler.h"
 
-command_context_t parse_command(uint8_t *command, uint8_t command_len) {
-  // Create the context
-  command_context_t context;
+// Initialize empty, global command context
+volatile command_context_t context = {UNKNOWN_COMMAND, SRC_NONE, FAN_NONE,
+                                      CNF_NONE};
 
+void parse_command(uint8_t command[], uint8_t command_len) {
   ///////////////////////
   // Command selection //
   ///////////////////////
@@ -11,11 +12,12 @@ command_context_t parse_command(uint8_t *command, uint8_t command_len) {
   // Validate that we have a command
   if (command_len < 1) {
     context.command = UNKNOWN_COMMAND;
-    return context;
   }
 
+  uint8_t foo = command[0];
+
   // Figure out which command to run
-  switch (command[0]) {
+  switch (foo) {
   case 0x11: // Read config
     context.command = READ_CONFIG;
     break;
@@ -48,14 +50,14 @@ command_context_t parse_command(uint8_t *command, uint8_t command_len) {
 
   // Check if the command does not require a parameter. If it does not, return.
   if (context.command == READ_TERMPERATURE) {
-    return context;
+    return;
   }
 
   // Validate that we have a first parameter, else requirements for command are
   // not fulfilled. return unknown command.
   if (command_len < 2) {
     context.command = UNKNOWN_COMMAND;
-    return context;
+    return;
   }
 
   // Store the parameter
@@ -109,14 +111,14 @@ command_context_t parse_command(uint8_t *command, uint8_t command_len) {
   // Check if the command does not require a second parameter. If it does not,
   // return. Only config write requires a second parameter.
   if (context.command != WRITE_CONFIG) {
-    return context;
+    return;
   }
 
   // Validate that we have a first parameter, else requirements for command are
   // not fulfilled. return unknown command.
   if (command_len < 3) {
     context.command = UNKNOWN_COMMAND;
-    return context;
+    return;
   }
 
   // Store the parameter
@@ -124,8 +126,32 @@ command_context_t parse_command(uint8_t *command, uint8_t command_len) {
 
   // TODO: Handle the config parameters
 
-  // Return the context
-  return context;
+  // exit
+  return;
 }
 
-void route_command(command_context_t command);
+uint8_t route_command() {
+  switch (context.command) {
+  WRITE_CONFIG:
+    return WRITE_CONFIG;
+    break;
+  READ_CONFIG:
+    return READ_CONFIG;
+    break;
+  READ_VOLTAGE:
+    return READ_VOLTAGE;
+    break;
+  READ_TERMPERATURE:
+    return READ_TERMPERATURE;
+    break;
+  READ_FAN_SPEED:
+    return READ_FAN_SPEED;
+    break;
+  CLEAR_BULK_FAN_SPEED:
+    return CLEAR_BULK_FAN_SPEED;
+    break;
+  UNKNOWN_COMMAND:
+    return 0xFF;
+    break;
+  }
+}

prosjekt.X/command-handler.h

@@ -12,6 +12,7 @@
 extern "C" {
 #endif
 
+#include <avr/io.h>
 #include <stdint.h>
 #include <string.h>
 
@@ -59,10 +60,10 @@ typedef struct {
 } command_context_t;
 
 // Parses the input string and outputs one of the valid commands
-command_context_t parse_command(uint8_t *command, uint8_t command_len);
+void parse_command(uint8_t *command, uint8_t command_len);
 
 // Routes the provided command to the appropriate function to handle it
-void route_command(command_context_t command);
+uint8_t route_command();
 
 #ifdef __cplusplus
 }

prosjekt.X/i2c.c

@@ -1,18 +1,26 @@
 #include "i2c.h"
+#include "command-handler.h"
 
-// Basic I2C handling structure is heavily inspired by: https://github.com/microchip-pic-avr-examples/avr128db48-bare-metal-twi-mplab/blob/master/twi-client.X/peripherals/TWI/TWI_client.c
+// Basic I2C handling structure is heavily inspired by:
+// https://github.com/microchip-pic-avr-examples/avr128db48-bare-metal-twi-mplab/blob/master/twi-client.X/peripherals/TWI/TWI_client.c
 
-volatile uint8_t i2c_recv[I2C_RECV_BUF_SIZE]; // Arbitrary length array to hold the received data, longer than max expected command
-volatile uint8_t i2c_recv_len;
+// We need to keep track of if the stop confition is in regards to a write or
+// read request
+volatile bool last_action_write = false;
+
+volatile uint8_t i2c_recv[I2C_RECV_BUF_SIZE] = {
+    0}; // Arbitrary length array to hold the received
+        // data, longer than max expected command
+volatile uint8_t i2c_recv_len = 0;
 
 void init_i2c(void) {
   // Pin setup
   PORTA.DIRSET = PIN2_bm | PIN3_bm;
   PORTA.PINCTRLUPD = PIN2_bm | PIN3_bm;
-    
+
   // Enable operating in debug
   TWI0.DBGCTRL = TWI_DBGRUN_bm;
-    
+
   // Initialize the control A register
   TWI0.CTRLA = TWI_INPUTLVL_I2C_gc    // I2C voltage transition level
                | TWI_SDASETUP_4CYC_gc // Four clock cycles setup time
@@ -30,7 +38,7 @@ void init_i2c(void) {
                 | PIN2_bm       // Respond to all TWI addresses
                 | TWI_ENABLE_bm // Enable acting as a slave
       ;
-  
+
   // Reset the received stuff
   i2c_reset_recv();
 }
@@ -39,59 +47,73 @@ void init_i2c(void) {
 void i2c_reset_recv() {
   i2c_recv_len = 0;
   for (int i = 0; i < I2C_RECV_BUF_SIZE; i++) {
-      i2c_recv[i] = 0;
+    i2c_recv[i] = 0;
   }
 }
 
 void i2c_write_handler(uint8_t data) {
-    i2c_recv[i2c_recv_len] = data;
-    i2c_recv_len++;
+  last_action_write = true;
+  i2c_recv[i2c_recv_len] = data;
+  i2c_recv_len++;
 }
 
 void i2c_read_handler() {
-    printf("Master wanted to read.\n");
+  last_action_write = false;
+  TWI0.SDATA = route_command();
 }
 
 void i2c_stop_handler() {
-    // Reset counter and clear receive buffer
-    i2c_recv[i2c_recv_len] = '\0';
-    printf("%s\n", i2c_recv);
-    i2c_reset_recv();
+  if (last_action_write) {
+    // Parse the received command data
+    parse_command(i2c_recv, i2c_recv_len);
+  } else {
+    // route_command();
+    ;
+  }
+  // Reset the buffer for future transmissions
+  i2c_reset_recv();
 }
 
 // Address received
 ISR(TWI0_TWIS_vect) {
-    // Check for the data interrupt flag
-    if (TWI0.SSTATUS & TWI_DIF_bm) {
-        uint8_t data = 0;
-        
-        if ( ((TWI0.SSTATUS & TWI_DIR_bm) >> TWI_DIR_bp) == 0 ) {
-            // Data write Master -> Slave
-            data = TWI0.SDATA;
-            
-            // Send the data to the write handler
-            i2c_write_handler(data);
-        } else {
-            // Data read Master <- Slave
-            i2c_read_handler();
-            data = TWI0.SDATA;
-        }
-        
-        // Acknowledge having received
-        TWI0.SCTRLB = TWI_ACKACT_ACK_gc | TWI_SCMD_RESPONSE_gc;
+  // Disable interrupts while handling I2C
+  cli();
+
+  // Check for the data interrupt flag
+  if (TWI0.SSTATUS & TWI_DIF_bm) {
+    uint8_t data = 0;
+
+    if (((TWI0.SSTATUS & TWI_DIR_bm) >> TWI_DIR_bp) == 0) {
+      // Data write Master -> Slave
+      data = TWI0.SDATA;
+
+      // Send the data to the write handler
+      i2c_write_handler(data);
+    } else {
+      // Data read Master <- Slave
+      i2c_read_handler();
+      // data = TWI0.SDATA;
+      // TWI0.SDATA = 1;
     }
-    
-    // Check for address match or STOP
-    if (TWI0.SSTATUS & TWI_APIF_bm) {
-        
-        if (TWI0.SSTATUS & TWI_AP_ADR_gc) {
-            // Address match, just send ack
-            TWI0.SCTRLB = TWI_ACKACT_ACK_gc | TWI_SCMD_RESPONSE_gc;
-        } else {
-            // STOP condition received
-            i2c_stop_handler();
-            // Send ACK
-            TWI0.SCTRLB = TWI_ACKACT_ACK_gc | TWI_SCMD_RESPONSE_gc;
-        }
+
+    // Acknowledge having received
+    TWI0.SCTRLB = TWI_ACKACT_ACK_gc | TWI_SCMD_RESPONSE_gc;
+  }
+
+  // Check for address match or STOP
+  if (TWI0.SSTATUS & TWI_APIF_bm) {
+
+    if (TWI0.SSTATUS & TWI_AP_ADR_gc) {
+      // Address match, just send ack
+      TWI0.SCTRLB = TWI_ACKACT_ACK_gc | TWI_SCMD_RESPONSE_gc;
+    } else {
+      // STOP condition received
+      i2c_stop_handler();
+      // Send ACK
+      TWI0.SCTRLB = TWI_ACKACT_ACK_gc | TWI_SCMD_RESPONSE_gc;
     }
-}
+  }
+
+  // Re-enable interrupts
+  sei();
+}

prosjekt.X/i2c.h

@@ -13,13 +13,15 @@ extern "C" {
 #endif
 
 // Include the IO for I2C
-#include <avr/io.h>
-#include <avr/interrupt.h>
+#include "command-handler.h"
 #include "uart.h"
+#include <avr/interrupt.h>
+#include <avr/io.h>
+#include <stdbool.h>
 #include <util/twi.h>
 
 // Received data info
-#define I2C_RECV_BUF_SIZE   64
+#define I2C_RECV_BUF_SIZE 64
 
 // Reset recv to initial state
 void i2c_reset_recv();

prosjekt.X/main.c

@@ -11,17 +11,20 @@
 #include <stdlib.h>
 #include "uart.h"
 #include "i2c.h"
+#include "command-handler.h"
 #include <util/delay.h>
+#include <avr/io.h>
 
 int main() {    
     init_uart((uint16_t)9600);
     init_i2c();
     stdout = &USART_stream;
     
+    PORTB.DIRSET = PIN3_bm;
+    
     sei();
 
     while (1) {
-        printf("\n");
-        _delay_ms(500);
+        ;
     }
 }

prosjekt.X/nbproject/configurations.xml

@@ -149,6 +149,9 @@
         <property key="program-the-device-with-default-config-words" value="false"/>
         <property key="remove-unused-sections" value="true"/>
       </HI-TECH-LINK>
+      <Tool>
+        <property key="debugoptions.useswbreakpoints" value="true"/>
+      </Tool>
       <XC8-CO>
         <property key="coverage-enable" value=""/>
         <property key="stack-guidance" value="false"/>