ArduControl::ProtocolInfo ArduControl::protocol_info[2] =
{
- { 79, 14, 4 } // MM
+ { 79, 14, 4 }, // MM
+ { 0x3FFF, 126, 15 } // MFX
};
ArduControl::ArduControl(const string &dev):
serial(dev),
- debug(true),
+ debug(1),
power(false),
- next_refresh(refresh_cycle.end()),
- refresh_counter(0),
active_accessory(0),
- n_s88_octets(0),
+ s88(*this),
+ mfx_search(*this),
thread(*this)
{
+ PendingCommand cmd;
+ cmd.command[0] = READ_POWER_STATE;
+ cmd.length = 1;
+ push_command(cmd);
+
+ cmd.command[0] = MFX_SET_STATION_ID;
+ cmd.command[1] = 'R';
+ cmd.command[2] = '2';
+ cmd.command[3] = 'C';
+ cmd.command[4] = '2';
+ cmd.length = 5;
+ push_command(cmd);
}
ArduControl::~ArduControl()
void ArduControl::set_power(bool p)
{
- if(p==power.pending)
- return;
-
- power.pending = p;
- ++power.serial;
-
- QueuedCommand cmd(POWER);
- cmd.tag.serial = power.serial;
- cmd.command[0] = (p ? POWER_ON : POWER_OFF);
- cmd.length = 1;
- push_command(cmd);
+ if(power.set(p))
+ {
+ PendingCommand cmd(POWER);
+ cmd.tag.serial = power.serial;
+ cmd.command[0] = (p ? POWER_ON : POWER_OFF);
+ cmd.length = 1;
+ push_command(cmd);
+ }
}
void ArduControl::halt(bool)
{
if(i==0)
return "MM";
+ else if(i==1)
+ return "MFX";
else
return 0;
}
void ArduControl::remove_loco(unsigned id)
{
Locomotive &loco = get_item(locomotives, id);
- remove_loco_from_refresh(loco);
+ refresh.remove_loco(loco);
locomotives.erase(id);
}
if(loco.speed.set(speed))
{
- QueuedCommand cmd(loco, Locomotive::SPEED);
+ PendingCommand cmd(loco, Locomotive::SPEED);
push_command(cmd);
- add_loco_to_refresh(loco);
+ refresh.add_loco(loco);
}
}
Locomotive &loco = get_item(locomotives, id);
if(loco.reverse.set(rev))
{
- QueuedCommand cmd(loco, Locomotive::REVERSE);
+ PendingCommand cmd(loco, Locomotive::REVERSE);
push_command(cmd);
- add_loco_to_refresh(loco);
+ refresh.add_loco(loco);
}
}
unsigned mask = 1<<func;
if(loco.funcs.set((loco.funcs&~mask)|(mask*state)))
{
- if(func>0)
+ if(func>0 || loco.proto!=MM)
{
- QueuedCommand cmd(loco, Locomotive::FUNCTIONS, func);
+ PendingCommand cmd(loco, Locomotive::FUNCTIONS, func);
push_command(cmd);
}
- add_loco_to_refresh(loco);
- }
-}
-
-void ArduControl::add_loco_to_refresh(Locomotive &loco)
-{
- MutexLock lock(mutex);
- refresh_cycle.push_back(&loco);
- if(refresh_cycle.size()>15)
- {
- LocomotivePtrList::iterator oldest = refresh_cycle.begin();
- for(LocomotivePtrList::iterator i=refresh_cycle.begin(); ++i!=refresh_cycle.end(); )
- if((*i)->last_change_age>(*oldest)->last_change_age)
- oldest = i;
- if(oldest==next_refresh)
- advance_next_refresh();
- refresh_cycle.erase(oldest);
- }
- if(next_refresh==refresh_cycle.end())
- next_refresh = refresh_cycle.begin();
-}
-
-void ArduControl::remove_loco_from_refresh(Locomotive &loco)
-{
- MutexLock lock(mutex);
- for(LocomotivePtrList::iterator i=refresh_cycle.begin(); i!=refresh_cycle.end(); ++i)
- if(*i==&loco)
- {
- if(i==next_refresh)
- {
- if(refresh_cycle.size()>1)
- advance_next_refresh();
- else
- next_refresh = refresh_cycle.end();
- }
- refresh_cycle.erase(i);
- return;
- }
-}
-
-ArduControl::Locomotive *ArduControl::get_loco_to_refresh()
-{
- MutexLock lock(mutex);
- if(refresh_cycle.empty())
- return 0;
-
- Locomotive *loco = *next_refresh;
- advance_next_refresh();
- return loco;
-}
-
-void ArduControl::advance_next_refresh()
-{
- ++next_refresh;
- if(next_refresh==refresh_cycle.end())
- {
- next_refresh = refresh_cycle.begin();
- ++refresh_counter;
+ refresh.add_loco(loco);
}
}
throw invalid_argument("ArduControl::add_sensor");
insert_unique(sensors, addr, Sensor(addr));
- unsigned octet_index = (addr-1)/8;
- if(octet_index>=n_s88_octets)
- n_s88_octets = octet_index+1;
+ s88.grow_n_octets((addr+7)/8);
return addr;
}
void ArduControl::remove_sensor(unsigned addr)
{
remove_existing(sensors, addr);
- // TODO update n_s88_octets
+ // TODO update s88.n_octets
}
bool ArduControl::get_sensor(unsigned addr) const
unsigned i;
for(i=0; (lowest_bit>>i)>1; ++i) ;
acc.state.set(acc.state^lowest_bit);
- QueuedCommand cmd(acc, Accessory::ACTIVATE, i);
+ PendingCommand cmd(acc, Accessory::ACTIVATE, i);
push_command(cmd);
}
else
if(t>off_timeout)
{
off_timeout = Time::TimeStamp();
- QueuedCommand cmd(*active_accessory, Accessory::DEACTIVATE);
+ PendingCommand cmd(*active_accessory, Accessory::DEACTIVATE);
push_command(cmd);
}
}
{
}
-void ArduControl::push_command(const QueuedCommand &cmd)
+void ArduControl::push_command(const PendingCommand &cmd)
{
MutexLock lock(mutex);
command_queue.push_back(cmd);
}
-bool ArduControl::pop_command(QueuedCommand &cmd)
+bool ArduControl::pop_command(PendingCommand &cmd)
{
MutexLock lock(mutex);
if(command_queue.empty())
buffer[3] = speed.pending+reverse.pending*0x80;
return 4;
}
+ else if(proto==MFX)
+ {
+ buffer[0] = MFX_SPEED;
+ buffer[1] = address>>8;
+ buffer[2] = address;
+ buffer[3] = speed.pending+reverse.pending*0x80;
+ return 4;
+ }
else
return 0;
}
buffer[3] = speed.pending;
return 4;
}
+ else if(proto==MFX)
+ {
+ bool f16 = (funcs.pending>0xFF);
+ buffer[0] = (f16 ? MFX_SPEED_FUNCS16 : MFX_SPEED_FUNCS8);
+ buffer[1] = address>>8;
+ buffer[2] = address;
+ buffer[3] = speed.pending+reverse.pending*0x80;
+ if(f16)
+ {
+ buffer[4] = funcs.pending>>8;
+ buffer[5] = funcs.pending;
+ return 6;
+ }
+ else
+ {
+ buffer[4] = funcs.pending;
+ return 5;
+ }
+ }
else
return 0;
}
{ }
-ArduControl::ControlThread::ControlThread(ArduControl &c):
- control(c),
- done(false)
+ArduControl::PendingCommand::PendingCommand():
+ length(0),
+ repeat_count(1)
+{ }
+
+ArduControl::PendingCommand::PendingCommand(GeneralCommand cmd):
+ length(0),
+ repeat_count(1)
{
- launch();
+ tag.type = Tag::GENERAL;
+ tag.command = cmd;
}
-void ArduControl::ControlThread::exit()
+ArduControl::PendingCommand::PendingCommand(Locomotive &loco, Locomotive::Command cmd, unsigned index):
+ repeat_count(8)
{
- done = true;
- join();
+ tag.type = Tag::LOCOMOTIVE;
+ tag.command = cmd;
+ tag.id = loco.id;
+ if(cmd==Locomotive::SPEED)
+ {
+ tag.serial = loco.speed.serial;
+ length = loco.create_speed_dir_command(command);
+ }
+ else if(cmd==Locomotive::REVERSE)
+ {
+ tag.serial = loco.reverse.serial;
+ length = loco.create_speed_dir_command(command);
+ }
+ else if(cmd==Locomotive::FUNCTIONS)
+ {
+ tag.serial = loco.funcs.serial;
+ length = loco.create_speed_func_command(index, command);
+ }
+ else
+ throw invalid_argument("PendingCommand");
}
-void ArduControl::ControlThread::main()
+ArduControl::PendingCommand::PendingCommand(Accessory &acc, Accessory::Command cmd, unsigned index):
+ repeat_count(1)
{
- char command[15];
- unsigned length = 0;
- unsigned repeat_count = 0;
- Tag tag;
- Locomotive *loco = 0;
- unsigned phase = 0;
- unsigned s88_octets_remaining = 0;
- while(!done)
+ tag.type = Tag::ACCESSORY;
+ tag.command = cmd;
+ tag.id = acc.address;
+ if(cmd==Accessory::ACTIVATE || cmd==Accessory::DEACTIVATE)
+ {
+ tag.serial = acc.state.serial;
+ length = acc.create_state_command(index, (cmd==Accessory::ACTIVATE), command);
+ }
+ else
+ throw invalid_argument("PendingCommand");
+}
+
+
+ArduControl::RefreshTask::RefreshTask():
+ next(cycle.end()),
+ round(0),
+ loco(0),
+ phase(0)
+{ }
+
+bool ArduControl::RefreshTask::get_work(PendingCommand &cmd)
+{
+ if(loco && loco->proto==MM && phase==0)
+ {
+ cmd.length = loco->create_speed_func_command(round%4+1, cmd.command);
+ cmd.repeat_count = 2;
+ ++phase;
+ return true;
+ }
+
+ loco = get_next_loco();
+ if(!loco)
+ return false;
+
+ phase = 0;
+ if(loco->proto==MM)
+ {
+ cmd.length = loco->create_speed_dir_command(cmd.command);
+ cmd.repeat_count = 2;
+ }
+ else if(loco->proto==MFX)
+ cmd.length = loco->create_speed_func_command(0, cmd.command);
+ else
+ return false;
+
+ return true;
+}
+
+void ArduControl::RefreshTask::add_loco(Locomotive &l)
+{
+ MutexLock lock(mutex);
+ cycle.push_back(&l);
+ if(cycle.size()>15)
{
- if(!repeat_count)
+ LocomotivePtrList::iterator oldest = cycle.begin();
+ for(LocomotivePtrList::iterator i=cycle.begin(); ++i!=cycle.end(); )
+ if((*i)->last_change_age>(*oldest)->last_change_age)
+ oldest = i;
+ if(oldest==next)
+ advance();
+ cycle.erase(oldest);
+ }
+ if(next==cycle.end())
+ next = cycle.begin();
+}
+
+void ArduControl::RefreshTask::remove_loco(Locomotive &l)
+{
+ MutexLock lock(mutex);
+ for(LocomotivePtrList::iterator i=cycle.begin(); i!=cycle.end(); ++i)
+ if(*i==&l)
{
- tag = Tag();
- length = 0;
- repeat_count = 1;
- QueuedCommand qcmd;
- if(control.pop_command(qcmd))
- {
- length = qcmd.length;
- copy(qcmd.command, qcmd.command+length, command);
- if(qcmd.tag.type==Tag::LOCOMOTIVE)
- repeat_count = 8;
- tag = qcmd.tag;
- }
- else if(loco && phase==0)
+ if(i==next)
{
- length = loco->create_speed_func_command(control.refresh_counter%4+1, command);
- repeat_count = 2;
- ++phase;
- }
- else if(!s88_octets_remaining && control.n_s88_octets)
- {
- command[0] = S88_READ;
- command[1] = control.n_s88_octets;
- length = 2;
- s88_octets_remaining = control.n_s88_octets;
- }
- else if((loco = control.get_loco_to_refresh()))
- {
- length = loco->create_speed_dir_command(command);
- repeat_count = 2;
- phase = 0;
- }
- else
- {
- // Send an idle packet for the MM protocol
- command[0] = MOTOROLA_SPEED;
- command[1] = 80;
- command[2] = 0;
- command[3] = 0;
- length = 4;
+ if(cycle.size()>1)
+ advance();
+ else
+ next = cycle.end();
}
+ cycle.erase(i);
+ return;
}
+}
- if(control.debug)
+ArduControl::Locomotive *ArduControl::RefreshTask::get_next_loco()
+{
+ MutexLock lock(mutex);
+ if(cycle.empty())
+ return 0;
+
+ Locomotive *l = *next;
+ advance();
+ return l;
+}
+
+void ArduControl::RefreshTask::advance()
+{
+ ++next;
+ if(next==cycle.end())
+ {
+ next= cycle.begin();
+ ++round;
+ }
+}
+
+
+ArduControl::S88Task::S88Task(ArduControl &c):
+ control(c),
+ n_octets(0),
+ octets_remaining(0)
+{ }
+
+bool ArduControl::S88Task::get_work(PendingCommand &cmd)
+{
+ if(octets_remaining || !n_octets)
+ return false;
+
+ octets_remaining = n_octets;
+ cmd.command[0] = S88_READ;
+ cmd.command[1] = octets_remaining;
+ cmd.length = 2;
+
+ return true;
+}
+
+void ArduControl::S88Task::process_reply(const char *reply, unsigned length)
+{
+ unsigned char type = reply[0];
+ if(type==S88_DATA && length>2)
+ {
+ unsigned offset = static_cast<unsigned char>(reply[1]);
+ unsigned count = length-2;
+
+ SensorMap::iterator begin = control.sensors.lower_bound(offset*8+1);
+ SensorMap::iterator end = control.sensors.upper_bound((offset+count)*8);
+ for(SensorMap::iterator i=begin; i!=end; ++i)
{
- string cmd_hex;
- for(unsigned i=0; i<length; ++i)
- cmd_hex += format(" %02X", static_cast<unsigned char>(command[i]));
- IO::print("< %02X%s\n", length^0xFF, cmd_hex);
+ unsigned bit_index = i->first-1-offset*8;
+ bool state = (reply[2+bit_index/8]>>(7-bit_index%8))&1;
+ i->second.state.set(state);
+
+ Tag tag;
+ tag.type = Tag::SENSOR;
+ tag.command = Sensor::STATE;
+ tag.serial = i->second.state.serial;
+ tag.id = i->first;
+ control.push_completed_tag(tag);
}
- control.serial.put(length^0xFF);
- control.serial.write(command, length);
- --repeat_count;
+ if(count>octets_remaining)
+ octets_remaining = 0;
+ else
+ octets_remaining -= count;
+ }
+}
- bool got_reply = false;
- bool got_data = false;
- while(!got_reply || got_data)
- {
- if(got_reply)
- got_data = IO::poll(control.serial, IO::P_INPUT, Time::zero);
- else
- got_data = IO::poll(control.serial, IO::P_INPUT);
+void ArduControl::S88Task::set_n_octets(unsigned n)
+{
+ n_octets = n;
+}
- if(got_data)
- {
- unsigned rlength = control.serial.get()^0xFF;
- if(rlength>15)
- {
- IO::print("Invalid length %02X\n", rlength);
- continue;
- }
+void ArduControl::S88Task::grow_n_octets(unsigned n)
+{
+ if(n>n_octets)
+ n_octets = n;
+}
- char reply[15];
- unsigned pos = 0;
- while(pos<rlength)
- pos += control.serial.read(reply+pos, rlength-pos);
- if(control.debug)
- {
- string reply_hex;
- for(unsigned i=0; i<rlength; ++i)
- reply_hex += format(" %02X", static_cast<unsigned char>(reply[i]));
- IO::print("> %02X%s\n", rlength^0xFF, reply_hex);
- }
+ArduControl::MfxAnnounceTask::MfxAnnounceTask():
+ serial(0)
+{ }
- unsigned char type = reply[0];
- if((type&0xE0)==0x80)
- {
- got_reply = true;
- if(type!=COMMAND_OK)
- IO::print("Error %02X\n", type);
- else if(tag && !repeat_count)
- control.push_completed_tag(tag);
- }
- else if(type==S88_DATA && rlength>2)
- {
- unsigned offset = static_cast<unsigned char>(reply[1]);
- unsigned count = rlength-2;
+bool ArduControl::MfxAnnounceTask::get_work(PendingCommand &cmd)
+{
+ Time::TimeStamp t = Time::now();
+ if(t<next)
+ return false;
- SensorMap::iterator begin = control.sensors.lower_bound(offset*8+1);
- SensorMap::iterator end = control.sensors.upper_bound((offset+count)*8);
- for(SensorMap::iterator i=begin; i!=end; ++i)
- {
- unsigned bit_index = i->first-1-offset*8;
- bool state = (reply[2+bit_index/8]>>(7-bit_index%8))&1;
- i->second.state.set(state);
-
- Tag stag;
- stag.type = Tag::SENSOR;
- stag.command = Sensor::STATE;
- stag.serial = i->second.state.serial;
- stag.id = i->first;
- control.push_completed_tag(stag);
- }
+ cmd.command[0] = MFX_ANNOUNCE;
+ cmd.command[1] = serial>>8;
+ cmd.command[2] = serial;
+ cmd.length = 3;
+ next = t+400*Time::msec;
- if(count>s88_octets_remaining)
- s88_octets_remaining = 0;
- else
- s88_octets_remaining -= count;
- }
+ return true;
+}
+
+void ArduControl::MfxAnnounceTask::set_serial(unsigned s)
+{
+ serial = s;
+}
+
+
+ArduControl::MfxSearchTask::MfxSearchTask(ArduControl &c):
+ control(c),
+ next_address(1),
+ size(0),
+ bits(0),
+ pending(false)
+{ }
+
+bool ArduControl::MfxSearchTask::get_work(PendingCommand &cmd)
+{
+ if(size==32)
+ {
+ if(control.debug>=1)
+ IO::print("Assigning MFX address %d to decoder %08X\n", next_address, bits);
+
+ cmd.command[0] = MFX_ASSIGN_ADDRESS;
+ cmd.command[1] = next_address>>8;
+ cmd.command[2] = next_address;
+ for(unsigned i=0; i<4; ++i)
+ cmd.command[3+i] = bits>>(24-i*8);
+ cmd.length = 7;
+
+ size = 0;
+ bits = 0;
+ ++next_address;
+
+ return true;
+ }
+
+ Time::TimeStamp t = Time::now();
+ if(t<next)
+ return false;
+
+ cmd.command[0] = MFX_SEARCH;
+ for(unsigned i=0; i<4; ++i)
+ cmd.command[1+i] = bits>>(24-i*8);
+ cmd.command[5] = size;
+ cmd.length = 6;
+
+ next = t+200*Time::msec;
+ pending = true;
+
+ if(control.debug>=1)
+ IO::print("Search %08X/%d\n", bits, size);
+
+ return true;
+}
+
+void ArduControl::MfxSearchTask::process_reply(const char *reply, unsigned length)
+{
+ unsigned char type = reply[0];
+ if(type==MFX_FEEDBACK && length==2 && pending)
+ {
+ pending = false;
+ bool finished = true;
+ if(reply[1])
+ {
+ if(size<32)
+ ++size;
+ finished = false;
+ }
+ else if(size>0)
+ {
+ unsigned mask = 1<<(32-size);
+ if(!(bits&mask))
+ {
+ bits |= mask;
+ finished = false;
}
}
+
+ if(finished)
+ {
+ next = Time::now()+2*Time::sec;
+ bits = 0;
+ size = 0;
+ }
}
}
-ArduControl::QueuedCommand::QueuedCommand():
- length(0)
-{ }
+ArduControl::ControlThread::ControlThread(ArduControl &c):
+ control(c),
+ done(false)
+{
+ tasks.push_back(&control.mfx_announce);
+ tasks.push_back(&control.mfx_search);
+ tasks.push_back(&control.s88);
+ tasks.push_back(&control.refresh);
+
+ launch();
+}
-ArduControl::QueuedCommand::QueuedCommand(GeneralCommand cmd):
- length(0)
+void ArduControl::ControlThread::exit()
{
- tag.type = Tag::GENERAL;
- tag.command = cmd;
+ done = true;
+ join();
}
-ArduControl::QueuedCommand::QueuedCommand(Locomotive &loco, Locomotive::Command cmd, unsigned index)
+void ArduControl::ControlThread::main()
{
- tag.type = Tag::LOCOMOTIVE;
- tag.command = cmd;
- tag.id = loco.id;
- if(cmd==Locomotive::SPEED)
+ while(!done)
{
- tag.serial = loco.speed.serial;
- length = loco.create_speed_dir_command(command);
+ PendingCommand cmd;
+ if(get_work(cmd))
+ {
+ bool success = true;
+ for(unsigned i=0; (success && i<cmd.repeat_count); ++i)
+ success = (do_command(cmd)==COMMAND_OK);
+ if(success && cmd.tag)
+ control.push_completed_tag(cmd.tag);
+ }
+ else
+ Time::sleep(10*Time::msec);
}
- else if(cmd==Locomotive::REVERSE)
+}
+
+bool ArduControl::ControlThread::get_work(PendingCommand &cmd)
+{
+ if(control.pop_command(cmd))
+ return true;
+
+ for(vector<Task *>::iterator i=tasks.begin(); i!=tasks.end(); ++i)
+ if((*i)->get_work(cmd))
+ return true;
+
+ // As fallback, send an idle packet for the MM protocol
+ cmd.command[0] = MOTOROLA_SPEED;
+ cmd.command[1] = 80;
+ cmd.command[2] = 0;
+ cmd.command[3] = 0;
+ cmd.length = 4;
+
+ return true;
+}
+
+unsigned ArduControl::ControlThread::do_command(const PendingCommand &cmd)
+{
+ if(control.debug>=2)
{
- tag.serial = loco.reverse.serial;
- length = loco.create_speed_dir_command(command);
+ string cmd_hex;
+ for(unsigned i=0; i<cmd.length; ++i)
+ cmd_hex += format(" %02X", static_cast<unsigned char>(cmd.command[i]));
+ IO::print("< %02X%s\n", cmd.length^0xFF, cmd_hex);
}
- else if(cmd==Locomotive::FUNCTIONS)
+
+ control.serial.put(cmd.length^0xFF);
+ control.serial.write(cmd.command, cmd.length);
+
+ unsigned result = 0;
+ while(1)
{
- tag.serial = loco.funcs.serial;
- length = loco.create_speed_func_command(index, command);
+ bool got_data;
+ if(result)
+ got_data = IO::poll(control.serial, IO::P_INPUT, Time::zero);
+ else
+ got_data = IO::poll(control.serial, IO::P_INPUT);
+
+ if(!got_data)
+ break;
+
+ unsigned rlength = control.serial.get()^0xFF;
+ if(rlength>15)
+ {
+ IO::print("Invalid length %02X\n", rlength);
+ continue;
+ }
+
+ char reply[15];
+ unsigned pos = 0;
+ while(pos<rlength)
+ pos += control.serial.read(reply+pos, rlength-pos);
+
+ if(control.debug>=2)
+ {
+ string reply_hex;
+ for(unsigned i=0; i<rlength; ++i)
+ reply_hex += format(" %02X", static_cast<unsigned char>(reply[i]));
+ IO::print("> %02X%s\n", rlength^0xFF, reply_hex);
+ }
+
+ unsigned r = process_reply(reply, rlength);
+ if(r && !result)
+ result = r;
}
- else
- throw invalid_argument("QueuedCommand");
+
+ return result;
}
-ArduControl::QueuedCommand::QueuedCommand(Accessory &acc, Accessory::Command cmd, unsigned index)
+unsigned ArduControl::ControlThread::process_reply(const char *reply, unsigned rlength)
{
- tag.type = Tag::ACCESSORY;
- tag.command = cmd;
- tag.id = acc.address;
- if(cmd==Accessory::ACTIVATE || cmd==Accessory::DEACTIVATE)
+ unsigned char type = reply[0];
+ if((type&0xE0)==0x80)
{
- tag.serial = acc.state.serial;
- length = acc.create_state_command(index, (cmd==Accessory::ACTIVATE), command);
+ if(type!=COMMAND_OK)
+ IO::print("Error %02X\n", type);
+ return type;
+ }
+ else if(type==POWER_STATE && rlength==2)
+ {
+ control.power.set(reply[1]);
+
+ Tag tag;
+ tag.type = Tag::GENERAL;
+ tag.command = POWER;
+ tag.serial = control.power.serial;
+ control.push_completed_tag(tag);
}
else
- throw invalid_argument("QueuedCommand");
+ {
+ for(vector<Task *>::iterator i=tasks.begin(); i!=tasks.end(); ++i)
+ (*i)->process_reply(reply, rlength);
+ }
+
+ return 0;
}
} // namespace R2C2