/* mbed AX-12+ Servo Library * * Copyright (c) 2010, cstyles (http://mbed.org) * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "AX12.h" #include "mbed.h" AX12::AX12(PinName tx, PinName rx, int ID, int baud) : _ax12(tx,rx) { _baud = baud; _ID = ID; _ax12.baud(_baud); } // Set the mode of the servo // 0 = Positional (0-300 degrees) // 1 = Rotational -1 to 1 speed int AX12::SetMode(int mode) { if (mode == 1) { // set CR SetCWLimit(0); SetCCWLimit(0); SetCRSpeed(0.0); } else { SetCWLimit(0); SetCCWLimit(300); SetCRSpeed(0.0); } return(0); } // if flag[0] is set, were blocking // if flag[1] is set, we're registering // they are mutually exclusive operations int AX12::SetGoal(int degrees, int flags) { char reg_flag = 0; char data[2]; // set the flag is only the register bit is set in the flag if (flags == 0x2) { reg_flag = 1; } // 1023 / 300 * degrees short goal = (1023 * degrees) / 300; #ifdef AX12_DEBUG printf("SetGoal to 0x%x\n",goal); #endif data[0] = goal & 0xff; // bottom 8 bits data[1] = goal >> 8; // top 8 bits // write the packet, return the error code int rVal = write(_ID, AX12_REG_GOAL_POSITION, 2, data, reg_flag); if (flags == 1) { // block until it comes to a halt while (isMoving()) {} } return(rVal); } // Set continuous rotation speed from -1 to 1 int AX12::SetCRSpeed(float speed) { // bit 10 = direction, 0 = CCW, 1=CW // bits 9-0 = Speed char data[2]; int goal = (0x3ff * abs(speed)); // Set direction CW if we have a negative speed if (speed < 0) { goal |= (0x1 << 10); } data[0] = goal & 0xff; // bottom 8 bits data[1] = goal >> 8; // top 8 bits // write the packet, return the error code int rVal = write(_ID, 0x20, 2, data); return(rVal); } int AX12::SetCWLimit (int degrees) { char data[2]; // 1023 / 300 * degrees short limit = (1023 * degrees) / 300; #ifdef AX12_DEBUG printf("SetCWLimit to 0x%x\n",limit); #endif data[0] = limit & 0xff; // bottom 8 bits data[1] = limit >> 8; // top 8 bits // write the packet, return the error code return (write(_ID, AX12_REG_CW_LIMIT, 2, data)); } int AX12::SetCCWLimit (int degrees) { char data[2]; // 1023 / 300 * degrees short limit = (1023 * degrees) / 300; #ifdef AX12_DEBUG printf("SetCCWLimit to 0x%x\n",limit); #endif data[0] = limit & 0xff; // bottom 8 bits data[1] = limit >> 8; // top 8 bits // write the packet, return the error code return (write(_ID, AX12_REG_CCW_LIMIT, 2, data)); } int AX12::SetID (int CurrentID, int NewID) { char data[1]; data[0] = NewID; #ifdef AX12_DEBUG printf("Setting ID from 0x%x to 0x%x\n",CurrentID,NewID); #endif return (write(CurrentID, AX12_REG_ID, 1, data)); } int AX12::SetBaud (int baud) { char data[1]; data[0] = baud; #ifdef AX12_DEBUG printf("Setting Baud rate to %d\n",baud); #endif return (write(0xFE, AX12_REG_BAUD, 1, data)); } // return 1 is the servo is still in flight int AX12::isMoving(void) { char data[1]; read(_ID,AX12_REG_MOVING,1,data); return(data[0]); } void AX12::trigger(void) { char TxBuf[16]; char sum = 0; #ifdef AX12_TRIGGER_DEBUG // Build the TxPacket first in RAM, then we'll send in one go printf("\nTriggered\n"); printf("\nTrigger Packet\n Header : 0xFF, 0xFF\n"); #endif TxBuf[0] = 0xFF; TxBuf[1] = 0xFF; // ID - Broadcast TxBuf[2] = 0xFE; sum += TxBuf[2]; #ifdef AX12_TRIGGER_DEBUG printf(" ID : %d\n",TxBuf[2]); #endif // Length TxBuf[3] = 0x02; sum += TxBuf[3]; #ifdef AX12_TRIGGER_DEBUG printf(" Length %d\n",TxBuf[3]); #endif // Instruction - ACTION TxBuf[4] = 0x04; sum += TxBuf[4]; #ifdef AX12_TRIGGER_DEBUG printf(" Instruction 0x%X\n",TxBuf[5]); #endif // Checksum TxBuf[5] = 0xFF - sum; #ifdef AX12_TRIGGER_DEBUG printf(" Checksum 0x%X\n",TxBuf[5]); #endif // Transmit the packet in one burst with no pausing for (int i = 0; i < 6 ; i++) { _ax12.putc(TxBuf[i]); } // This is a broadcast packet, so there will be no reply return; } float AX12::GetPosition(void) { #ifdef AX12_DEBUG printf("\nGetPosition(%d)",_ID); #endif char data[2]; int ErrorCode = read(_ID, AX12_REG_POSITION, 2, data); short position = data[0] + (data[1] << 8); float angle = (position * 300)/1024; return (angle); } float AX12::GetTemp (void) { #ifdef AX12_DEBUG printf("\nGetTemp(%d)",_ID); #endif char data[1]; int ErrorCode = read(_ID, AX12_REG_TEMP, 1, data); float temp = data[0]; return(temp); } float AX12::GetVolts (void) { #ifdef AX12_DEBUG printf("\nGetVolts(%d)",_ID); #endif char data[1]; int ErrorCode = read(_ID, AX12_REG_VOLTS, 1, data); float volts = data[0]/10.0; return(volts); } int AX12::read(int ID, int start, int bytes, char* data) { char PacketLength = 0x4; char TxBuf[16]; char sum = 0; char Status[16]; Status[4] = 0xFE; // return code #ifdef AX12_READ_DEBUG printf("\nread(%d,0x%x,%d,data)\n",ID,start,bytes); #endif // Build the TxPacket first in RAM, then we'll send in one go #ifdef AX12_READ_DEBUG printf("\nInstruction Packet\n Header : 0xFF, 0xFF\n"); #endif TxBuf[0] = 0xff; TxBuf[1] = 0xff; // ID TxBuf[2] = ID; sum += TxBuf[2]; #ifdef AX12_READ_DEBUG printf(" ID : %d\n",TxBuf[2]); #endif // Packet Length TxBuf[3] = PacketLength; // Length = 4 ; 2 + 1 (start) = 1 (bytes) sum += TxBuf[3]; // Accululate the packet sum #ifdef AX12_READ_DEBUG printf(" Length : 0x%x\n",TxBuf[3]); #endif // Instruction - Read TxBuf[4] = 0x2; sum += TxBuf[4]; #ifdef AX12_READ_DEBUG printf(" Instruction : 0x%x\n",TxBuf[4]); #endif // Start Address TxBuf[5] = start; sum += TxBuf[5]; #ifdef AX12_READ_DEBUG printf(" Start Address : 0x%x\n",TxBuf[5]); #endif // Bytes to read TxBuf[6] = bytes; sum += TxBuf[6]; #ifdef AX12_READ_DEBUG printf(" No bytes : 0x%x\n",TxBuf[6]); #endif // Checksum TxBuf[7] = 0xFF - sum; #ifdef AX12_READ_DEBUG printf(" Checksum : 0x%x\n",TxBuf[7]); #endif // Transmit the packet in one burst with no pausing for (int i = 0; i<8 ; i++) { _ax12.putc(TxBuf[i]); } // Wait for the bytes to be transmitted wait (0.00002); // Skip if the read was to the broadcast address if (_ID != 0xFE) { // response packet is always 6 + bytes // 0xFF, 0xFF, ID, Length Error, Param(s) Checksum // timeout is a little more than the time to transmit // the packet back, i.e. (6+bytes)*10 bit periods int timeout = 0; int plen = 0; while ((timeout < ((6+bytes)*10)) && (plen<(6+bytes))) { if (_ax12.readable()) { Status[plen] = _ax12.getc(); plen++; timeout = 0; } // wait for the bit period wait (1.0/_baud); timeout++; } if (timeout == ((6+bytes)*10) ) { return(-1); } // Copy the data from Status into data for return for (int i=0; i < Status[3]-2 ; i++) { data[i] = Status[5+i]; } #ifdef AX12_READ_DEBUG printf("\nStatus Packet\n"); printf(" Header : 0x%x\n",Status[0]); printf(" Header : 0x%x\n",Status[1]); printf(" ID : 0x%x\n",Status[2]); printf(" Length : 0x%x\n",Status[3]); printf(" Error Code : 0x%x\n",Status[4]); for (int i=0; i < Status[3]-2 ; i++) { printf(" Data : 0x%x\n",Status[5+i]); } printf(" Checksum : 0x%x\n",Status[5+(Status[3]-2)]); #endif } // if (ID!=0xFE) return(Status[4]); } int AX12::write(int ID, int start, int bytes, char* data, int flag) { // 0xff, 0xff, ID, Length, Intruction(write), Address, Param(s), Checksum char TxBuf[16]; char sum = 0; char Status[6]; #ifdef AX12_WRITE_DEBUG printf("\nwrite(%d,0x%x,%d,data,%d)\n",ID,start,bytes,flag); #endif // Build the TxPacket first in RAM, then we'll send in one go #ifdef AX12_WRITE_DEBUG printf("\nInstruction Packet\n Header : 0xFF, 0xFF\n"); #endif TxBuf[0] = 0xff; TxBuf[1] = 0xff; // ID TxBuf[2] = ID; sum += TxBuf[2]; #ifdef AX12_WRITE_DEBUG printf(" ID : %d\n",TxBuf[2]); #endif // packet Length TxBuf[3] = 3+bytes; sum += TxBuf[3]; #ifdef AX12_WRITE_DEBUG printf(" Length : %d\n",TxBuf[3]); #endif // Instruction if (flag == 1) { TxBuf[4]=0x04; sum += TxBuf[4]; } else { TxBuf[4]=0x03; sum += TxBuf[4]; } #ifdef AX12_WRITE_DEBUG printf(" Instruction : 0x%x\n",TxBuf[4]); #endif // Start Address TxBuf[5] = start; sum += TxBuf[5]; #ifdef AX12_WRITE_DEBUG printf(" Start : 0x%x\n",TxBuf[5]); #endif // data for (char i=0; i