Merge pull request #3436 from thinkyhead/rc_experimental_twibus

M155 and M156, a generic TWI/I2C interface for Marlin
master
Scott Lahteine 9 years ago
commit 3ecf38d32e

@ -653,6 +653,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -77,6 +77,10 @@
#include "stepper_dac.h" #include "stepper_dac.h"
#endif #endif
#if ENABLED(EXPERIMENTAL_I2CBUS)
#include "twibus.h"
#endif
/** /**
* Look here for descriptions of G-codes: * Look here for descriptions of G-codes:
* - http://linuxcnc.org/handbook/gcode/g-code.html * - http://linuxcnc.org/handbook/gcode/g-code.html
@ -248,6 +252,10 @@
CardReader card; CardReader card;
#endif #endif
#if ENABLED(EXPERIMENTAL_I2CBUS)
TWIBus i2c;
#endif
bool Running = true; bool Running = true;
uint8_t marlin_debug_flags = DEBUG_NONE; uint8_t marlin_debug_flags = DEBUG_NONE;
@ -4771,6 +4779,57 @@ inline void gcode_M121() { enable_endstops_globally(false); }
#endif // BLINKM #endif // BLINKM
#if ENABLED(EXPERIMENTAL_I2CBUS)
/**
* M155: Send data to a I2C slave device
*
* This is a PoC, the formating and arguments for the GCODE will
* change to be more compatible, the current proposal is:
*
* M155 A<slave device address base 10> ; Sets the I2C slave address the data will be sent to
*
* M155 B<byte-1 value in base 10>
* M155 B<byte-2 value in base 10>
* M155 B<byte-3 value in base 10>
*
* M155 S1 ; Send the buffered data and reset the buffer
* M155 R1 ; Reset the buffer without sending data
*
*/
inline void gcode_M155() {
// Set the target address
if (code_seen('A'))
i2c.address((uint8_t) code_value_short());
// Add a new byte to the buffer
else if (code_seen('B'))
i2c.addbyte((int) code_value_short());
// Flush the buffer to the bus
else if (code_seen('S')) i2c.send();
// Reset and rewind the buffer
else if (code_seen('R')) i2c.reset();
}
/**
* M156: Request X bytes from I2C slave device
*
* Usage: M156 A<slave device address base 10> B<number of bytes>
*/
inline void gcode_M156() {
uint8_t addr = code_seen('A') ? code_value_short() : 0;
int bytes = code_seen('B') ? code_value_short() : 0;
if (addr && bytes) {
i2c.address(addr);
i2c.reqbytes(bytes);
}
}
#endif //EXPERIMENTAL_I2CBUS
/** /**
* M200: Set filament diameter and set E axis units to cubic millimeters * M200: Set filament diameter and set E axis units to cubic millimeters
* *
@ -6439,6 +6498,18 @@ void process_next_command() {
#endif //BLINKM #endif //BLINKM
#if ENABLED(EXPERIMENTAL_I2CBUS)
case 155:
gcode_M155();
break;
case 156:
gcode_M156();
break;
#endif //EXPERIMENTAL_I2CBUS
case 200: // M200 D<millimeters> set filament diameter and set E axis units to cubic millimeters (use S0 to set back to millimeters). case 200: // M200 D<millimeters> set filament diameter and set E axis units to cubic millimeters (use S0 to set back to millimeters).
gcode_M200(); gcode_M200();
break; break;

@ -653,6 +653,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -653,6 +653,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -653,6 +653,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -659,6 +659,38 @@ const unsigned int dropsegments = 2; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -653,6 +653,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -653,6 +653,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -661,6 +661,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -653,6 +653,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -655,6 +655,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -655,6 +655,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -654,6 +654,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -659,6 +659,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -653,6 +653,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -653,6 +653,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -653,6 +653,38 @@ const unsigned int dropsegments = 5; //everything with less than this number of
#endif #endif
/**
* TWI/I2C BUS
*
* This feature is an EXPERIMENTAL feature so it shall not be used on production
* machines. Enabling this will allow you to send and receive I2C data from slave
* devices on the bus.
*
* ; Example #1
* ; This macro send the string "Marlin" to the slave device with address 0x63
* ; It uses multiple M155 commands with one B<base 10> arg
* M155 A63 ; Target slave address
* M155 B77 ; M
* M155 B97 ; a
* M155 B114 ; r
* M155 B108 ; l
* M155 B105 ; i
* M155 B110 ; n
* M155 S1 ; Send the current buffer
*
* ; Example #2
* ; Request 6 bytes from slave device with address 0x63
* M156 A63 B5
*
* ; Example #3
* ; Example serial output of a M156 request
* echo:i2c-reply: from:63 bytes:5 data:hello
*/
// @section i2cbus
//#define EXPERIMENTAL_I2CBUS
#include "Conditionals.h" #include "Conditionals.h"
#include "SanityCheck.h" #include "SanityCheck.h"

@ -0,0 +1,104 @@
/*
* Marlin 3D Printer Firmware
* Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "Marlin.h"
#if ENABLED(EXPERIMENTAL_I2CBUS)
#include "twibus.h"
#include <Wire.h>
TWIBus::twibus() {
Wire.begin(); // We use no address so we will join the BUS as the master
this->reset();
}
void TWIBus::reset() {
this->addr = 0;
this->buffer_s = 0;
this->buffer[0] = 0x00;
}
void TWIBus::address(uint8_t addr) {
this->addr = addr;
if (DEBUGGING(INFO)) {
SERIAL_ECHOPAIR("TWIBus::sendto: ", this->addr);
SERIAL_EOL;
}
}
void TWIBus::addbyte(char c) {
if (buffer_s >= sizeof(this->buffer)) return;
this->buffer[this->buffer_s++] = c;
if (DEBUGGING(INFO)) {
SERIAL_ECHOPAIR("TWIBus::addbyte: ", this->buffer[this->buffer_s -1]);
SERIAL_EOL;
}
}
void TWIBus::send() {
if (!this->addr) return;
if (DEBUGGING(INFO)) SERIAL_ECHOLNPGM("TWIBus::send()");
Wire.beginTransmission(this->addr);
Wire.write(this->buffer, this->buffer_s);
Wire.endTransmission();
// Reset the buffer after sending the data
this->reset();
}
void TWIBus::reqbytes(uint8_t bytes) {
if (!this->addr) return;
if (DEBUGGING(INFO)) {
SERIAL_ECHOPAIR("TWIBus::reqbytes(): ", bytes);
SERIAL_EOL;
}
millis_t t = millis();
Wire.requestFrom(this->addr, bytes);
// requestFrom() is a blocking function
while (Wire.available() < bytes) {
if (millis() - t >= this->timeout) break;
else continue;
}
SERIAL_ECHO_START;
SERIAL_ECHOPAIR("i2c-reply: from:", this->addr);
SERIAL_ECHOPAIR(" bytes:", Wire.available());
SERIAL_ECHOPGM (" data:");
// Protect against buffer overflows if the number of received bytes
// is less than the number of requested bytes
uint8_t wba = Wire.available();
for (int i = 0; i < wba; i++) SERIAL_CHAR(Wire.read());
SERIAL_EOL;
// Reset the buffer after sending the data
this->reset();
}
#endif //EXPERIMENTAL_I2CBUS

@ -0,0 +1,122 @@
/*
* Marlin 3D Printer Firmware
* Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef TWIBUS_H
#define TWIBUS_H
/**
* TWIBUS class
*
* This class implements a wrapper around the two wire (I2C) bus, it allows
* Marlin to send and request data from any slave device on the bus. This is
* an experimental feature and it's inner workings as well as public facing
* interface are prune to change in the future.
*
* The two main consumers of this class are M155 and M156, where M155 allows
* Marlin to send a I2C packet to a device (please be aware that no repeated
* starts are possible), this can be done in caching method by calling multiple
* times M155 B<byte-1 value in base 10> or a one liner M155, have a look at
* the gcode_M155() function for more information. M156 allows Marlin to
* request data from a device, the received data is then relayed into the serial
* line for host interpretation.
*
*/
class TWIBus {
private:
/**
* @brief Timeout value in milliseconds
* @details For blocking operations this constant value will set the max
* amount of time Marlin will keep waiting for a reply. Useful is something
* goes wrong on the bus and the SDA/SCL lines are held up by another device.
*/
const int timeout = 5;
/**
* @brief Target device address
* @description This stores, until the buffer is flushed, the target device
* address, take not we do follow Arduino 7bit addressing.
*/
uint8_t addr = 0;
/**
* @brief Number of bytes on buffer
* @description This var holds the total number of bytes on our buffer
* waiting to be flushed to the bus.
*/
uint8_t buffer_s = 0;
/**
* @brief Internal buffer
* @details This is a fixed buffer, TWI command cannot be longer than this
*/
char buffer[30];
public:
/**
* @brief Class constructor
* @details Initialized the TWI bus and clears the buffer
*/
TWIBus();
/**
* @brief Reset the buffer
* @details Brings the internal buffer to a known-empty state
*/
void reset();
/**
* @brief Send the buffer data to the bus
* @details Flushed the buffer into the bus targeting the cached slave device
* address.
*/
void send();
/**
* @brief Add one byte to the buffer
* @details Adds the byte to the buffer in a sequential way, if buffer is full
* the request is silently ignored.
*
* @param c a data byte
*/
void addbyte(char c);
/**
* @brief Sets the target slave address
* @details The target slave address is stored so it can be later used when
* the complete packet needs to be sent over the bus.
*
* @param addr 7-bit integer address
*/
void address(uint8_t addr);
/**
* @brief Request data from slave device
* @details Requests data from a slave device, when the data is received it will
* be relayed to the serial line using a parser-friendly formatting.
*
* @param bytes the number of bytes to request
*/
void reqbytes(uint8_t bytes);
};
#endif //TWIBUS_H
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