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mainloop blinks led to detect hangs, implemented the read command wit…
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…h lookahead, fixed readbyte return code
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@rambo
rambo committed Aug 12, 2012
1 parent c22bad7 commit 5deadf5
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Showing 3 changed files with 113 additions and 23 deletions.
39 changes: 35 additions & 4 deletions I2C.cpp
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Original file line number Original file line Diff line number Diff line change
Expand Up @@ -682,14 +682,45 @@ uint8_t I2C::receiveByte(uint8_t ack)
return(TWI_STATUS); return(TWI_STATUS);
} }


uint8_t I2C::receiveByte(uint8_t ack, uint8_t* target) uint8_t I2C::receiveByte(uint8_t ack, uint8_t *target)
{ {
uint8_t stat = I2C::receiveByte(ack); uint8_t stat = I2C::receiveByte(ack);
if (stat == 0) /*
if( i == nack )
{
returnStatus = receiveByte(0);
if(returnStatus == 1){return(6);}
if(returnStatus != MR_DATA_NACK){return(returnStatus);}
}
else
{
returnStatus = receiveByte(1);
if(returnStatus == 1){return(6);}
if(returnStatus != MR_DATA_ACK){return(returnStatus);}
}
*/
if (stat == 1)
{
return(6);
}
if (ack)
{
if(returnStatus != MR_DATA_ACK)
{
return(returnStatus);
}
}
else
{ {
target = TWDR; if(returnStatus != MR_DATA_NACK)
{
return(returnStatus);
}
} }
return stat; *target = TWDR;
// I suppose that if we get this far we're ok
return 0;
} }


uint8_t I2C::stop() uint8_t I2C::stop()
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2 changes: 1 addition & 1 deletion I2C.h
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Original file line number Original file line Diff line number Diff line change
Expand Up @@ -117,7 +117,7 @@ class I2C
uint8_t sendAddress(uint8_t); uint8_t sendAddress(uint8_t);
uint8_t sendByte(uint8_t); uint8_t sendByte(uint8_t);
uint8_t receiveByte(uint8_t); uint8_t receiveByte(uint8_t);
uint8_t receiveByte(uint8_t, uint8_t*); uint8_t receiveByte(uint8_t, uint8_t *target);
uint8_t stop(); uint8_t stop();
private: private:
void lockUp(); void lockUp();
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95 changes: 77 additions & 18 deletions examples/i2crepl/i2crepl.ino
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Original file line number Original file line Diff line number Diff line change
Expand Up @@ -19,13 +19,14 @@ byte incoming_position;
* Working: * Working:
* - start / stop * - start / stop
* - hex parsing (mostly) and sending * - hex parsing (mostly) and sending
* - reading
* *
* TODO: * TODO:
* - implement read (this is a bit complex as we need to know which of the read commands is last one so we can sen NACK instead of ACK to tell the slave to release the bus) * - fix hex parsing (there seems to be some bugs in it)
* - fix hex parsing for two-character values starting with 0 (it seems to fail)
* - REPL so this can be used via plain serial port as well * - REPL so this can be used via plain serial port as well
* - Smarter number parsing (0x to signify hex, othewise suppose decimal) * - Smarter number parsing (0x to signify hex, othewise suppose decimal)
* - address calculator for example "=" followed by hex prints the r and w 8-bit addresses for the device * - address calculator for example "=" followed by hex prints the r and w 8-bit addresses for the device
* - scan command (no longer does scan on boot to save time)
*/ */


void setup() void setup()
Expand All @@ -39,7 +40,7 @@ void setup()
I2c.pullup(true); I2c.pullup(true);


// Scan the bus // Scan the bus
I2c.scan(); //I2c.scan();
Serial.println("Remember that you need to send the 8-bit address (with R/W-bit set) when addressing a device"); Serial.println("Remember that you need to send the 8-bit address (with R/W-bit set) when addressing a device");
digitalWrite(13, LOW); digitalWrite(13, LOW);
} }
Expand Down Expand Up @@ -152,6 +153,18 @@ inline byte parse_hex(char *parsebuffer)
return ardubus_hex2byte(parsebuffer[0]); return ardubus_hex2byte(parsebuffer[0]);
} }


void invalid_char(byte character, byte pos)
{
Serial.print("Invalid character '");
Serial.write(character);
Serial.print("' (0x");
Serial.print(character, HEX);
Serial.print(") in position ");
Serial.print(pos, DEC);
Serial.println(" when parsing command");
}


inline void process_command() inline void process_command()
{ {
char hexparsebuffer[5]; char hexparsebuffer[5];
Expand Down Expand Up @@ -179,10 +192,8 @@ inline void process_command()
} }
else else
{ {
// Invalid char Serial.print("start_seen: ");
Serial.print("Invalid character in position "); invalid_char(current_char, i);
Serial.print(i, DEC);
Serial.println(" when parsing command");
return; return;
} }
} }
Expand All @@ -197,10 +208,8 @@ inline void process_command()
} }
else else
{ {
// Invalid char Serial.print("stop_seen: ");
Serial.print("Invalid character in position "); invalid_char(current_char, i);
Serial.print(i, DEC);
Serial.println(" when parsing command");
return; return;
} }
} }
Expand Down Expand Up @@ -243,20 +252,23 @@ inline void process_command()
} }
else else
{ {
// Invalid char Serial.print("in_hex: ");
Serial.print("Invalid character in position "); invalid_char(current_char, i);
Serial.print(i, DEC);
Serial.println(" when parsing command");
return; return;
} }
} }
break; break;
case p_idle: case p_idle:
{ {
boolean is_valid_char = false;
switch (current_char) switch (current_char)
{ {
case 0x20: // space
is_valid_char = true;
break;
case 0x5b: // ASCII "[", our start signifier case 0x5b: // ASCII "[", our start signifier
{ {
is_valid_char = true;
byte stat = I2c.start(); byte stat = I2c.start();
parser_state = start_seen; parser_state = start_seen;
Serial.print("START returned "); Serial.print("START returned ");
Expand All @@ -265,6 +277,7 @@ inline void process_command()
break; break;
case 0x5d: // ASCII "]", our stop signifier case 0x5d: // ASCII "]", our stop signifier
{ {
is_valid_char = true;
byte stat = I2c.stop(); byte stat = I2c.stop();
Serial.print("STOP returned "); Serial.print("STOP returned ");
Serial.println(stat, DEC); Serial.println(stat, DEC);
Expand All @@ -274,17 +287,61 @@ inline void process_command()
case 0x72: // ASCII "r", case 0x72: // ASCII "r",
case 0x52: // ASCII "R", read byte case 0x52: // ASCII "R", read byte
{ {
// TODO: How to figure out the last read ? is_valid_char = true;
byte tmpbuffer; // peek ahead to see if this was last r -command

boolean is_last = true;
byte peek_i = i+1;
while (peek_i < maxsize)
{
switch (incoming_command[peek_i])
{
case 0x72: // ASCII "r",
case 0x52: // ASCII "R", read byte
{
is_last = false;
}
break;
case 0x20: // space, command separator
// no-op
break;
case 0x5b: // ASCII "[", our start signifier
case 0x5d: // ASCII "]", our stop signifier
// no-ops too
break;
default:
// Any other command is in the wrong(est) place
Serial.print("r lookahead: ");
invalid_char(incoming_command[peek_i], peek_i);
return;

}
if (!is_last)
{
break;
}
peek_i++;
}
uint8_t tmpbuffer;
byte stat = I2c.receiveByte(!is_last, &tmpbuffer);
Serial.print("read 0x");
Serial.print(tmpbuffer, HEX);
Serial.print(" stat=");
Serial.println(stat, DEC);
} }
break; break;
} }
if (is_hex_char(current_char)) if (is_hex_char(current_char))
{ {
is_valid_char = true;
parser_state = in_hex; parser_state = in_hex;
hexparsebuffer[hexparsebuffer_i++] = current_char; hexparsebuffer[hexparsebuffer_i++] = current_char;
} }
if (!is_valid_char)
{
Serial.print("p_idle: ");
invalid_char(current_char, i);
return;
}
} }
break; break;
} }
Expand All @@ -294,4 +351,6 @@ inline void process_command()
void loop() void loop()
{ {
read_command_bytes(); read_command_bytes();
digitalWrite(13, !digitalRead(13));
delay(20);
} }

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