CAN.cpp

00001 #include "CAN.h"
00002 #include "used_leg_message.h"
00003 
00004 
00005 
00006 //定义设备
00007 CAN knee_can(PB_8, PB_9);                                                         // CAN Rx pin name, CAN Tx pin name
00008 CAN ankle_can(PB_12, PB_13);                                                       // CAN Rx pin name, CAN Tx pin name
00009 // 定义CAN消息
00010 CANMessage knee_rxMsg, ankle_rxMsg;                                                  // 主控收到的CAN消息
00011 CANMessage knee_txMsg, ankle_txMsg;                                           // 主控发送的CAN消息
00012 
00013 //=================================函数=======================================//
00014 
00015 /// 将控制参数打包入CAN消息中
00016 /// CAN Command Packet Structure
00017 /// 16 bit position command, between -4*pi and 4*pi
00018 /// 12 bit velocity command, between -30 and + 30 rad/s
00019 /// 12 bit kp, between 0 and 500 N-m/rad
00020 /// 12 bit kd, between 0 and 100 N-m*s/rad
00021 /// 12 bit feed forward torque, between -18 and 18 N-m
00022 /// CAN Packet is 8 8-bit words
00023 /// Formatted as follows.  For each quantity, bit 0 is LSB
00024 /// 0: [position[15-8]]
00025 /// 1: [position[7-0]] 
00026 /// 2: [velocity[11-4]]
00027 /// 3: [velocity[3-0], kp[11-8]]
00028 /// 4: [kp[7-0]]
00029 /// 5: [kd[11-4]]
00030 /// 6: [kd[3-0], torque[11-8]]
00031 /// 7: [torque[7-0]]
00032 void pack_cmd(CANMessage * msg, joint_control joint){
00033      
00034      /// limit data to be within bounds ///
00035      float p_des = fminf(fmaxf(P_MIN, joint.p_des), P_MAX);                    
00036      float v_des = fminf(fmaxf(V_MIN, joint.v_des), V_MAX);
00037      float kp = fminf(fmaxf(KP_MIN, joint.kp), KP_MAX);
00038      float kd = fminf(fmaxf(KD_MIN, joint.kd), KD_MAX);
00039      float t_ff = fminf(fmaxf(T_MIN, joint.t_ff), T_MAX);
00040      /// convert floats to unsigned ints ///
00041      uint16_t p_int = float_to_uint(p_des, P_MIN, P_MAX, 16);            
00042      uint16_t v_int = float_to_uint(v_des, V_MIN, V_MAX, 12);
00043      uint16_t kp_int = float_to_uint(kp, KP_MIN, KP_MAX, 12);
00044      uint16_t kd_int = float_to_uint(kd, KD_MIN, KD_MAX, 12);
00045      uint16_t t_int = float_to_uint(t_ff, T_MIN, T_MAX, 12);
00046      /// pack ints into the can buffer ///
00047      msg->data[0] = p_int>>8;                                       
00048      msg->data[1] = p_int&0xFF;
00049      msg->data[2] = v_int>>4;
00050      msg->data[3] = ((v_int&0xF)<<4)|(kp_int>>8);
00051      msg->data[4] = kp_int&0xFF;
00052      msg->data[5] = kd_int>>4;
00053      msg->data[6] = ((kd_int&0xF)<<4)|(t_int>>8);
00054      msg->data[7] = t_int&0xff;
00055 }
00056 
00057 
00058 // 多个控制器联合打包准备发送
00059 void PackAll(){
00060     pack_cmd(&knee_txMsg, a_control.knee); 
00061     pack_cmd(&ankle_txMsg, a_control.ankle); 
00062 }
00063 
00064 
00065 // 写联合打包的数据
00066 void WriteAll(){
00067     knee_can.write(knee_txMsg);
00068     wait(.00002);
00069     ankle_can.write(ankle_txMsg);
00070     wait(.00002);
00071 }
00072 
00073 
00074 /// 提取信息并存入状态结构体
00075 /// CAN Reply Packet Structure
00076 /// 16 bit position, between -4*pi and 4*pi
00077 /// 12 bit velocity, between -30 and + 30 rad/s
00078 /// 12 bit current, between -40 and 40;
00079 /// CAN Packet is 5 8-bit words
00080 /// Formatted as follows.  For each quantity, bit 0 is LSB
00081 /// 0: [position[15-8]]
00082 /// 1: [position[7-0]] 
00083 /// 2: [velocity[11-4]]
00084 /// 3: [velocity[3-0], current[11-8]]
00085 /// 4: [current[7-0]]
00086 void unpack_reply(CANMessage msg, leg_state * state){
00087     /// unpack ints from can buffer ///
00088     uint16_t id = msg.data[0];
00089     uint16_t p_int = (msg.data[1]<<8)|msg.data[2];
00090     uint16_t v_int = (msg.data[3]<<4)|(msg.data[4]>>4);
00091     uint16_t i_int = ((msg.data[4]&0xF)<<8)|msg.data[5];
00092     /// convert uints to floats ///
00093     float p = uint_to_float(p_int, P_MIN, P_MAX, 16);
00094     float v = uint_to_float(v_int, V_MIN, V_MAX, 12);
00095     float t = uint_to_float(i_int, -T_MAX, T_MAX, 12);
00096     
00097     if(id==0x02){
00098         state->knee_state.p = p;
00099         state->knee_state.v = v;
00100         state->knee_state.t = t;
00101         }
00102     else if(id==0x01){
00103         state->ankle_state.p = p;
00104         state->ankle_state.v = v;
00105         state->ankle_state.t = t;
00106         }
00107 } 
00108 
00109 
00110 
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