Overview:
Developers can use Dobot for second development, achieving various functions. This tutorial is avaliable for simple second development by Arduino MEGA2560.
Regarding to second development, please connect MEGA2560 with control board withDobot main control board through the interface of Bluetooth modul. At the same time, dial main control board to Bluetooth mode. Here are the wiring diagran:
Figure 1 connection mode
Connection Mode:
Step 1: Format of Issued Commands by Client
Dobot communication instruction uses fixed frame format. Each frame of data has （2 + 4 * 10） = 42bytes and includes packet head(0xA5), packet end(0x5A) and ten parameters. All these parameters are act as Dobot single precision floating point types(32-bit), among this each parameter is formed into 4 bytes, except voice control commands, packet head(0xB5) and packet end(0x5B). Here are as follows:
Figure 2 instruction format
Two arrays are defined as follows: One is 42 bytes sent to Dobot, another includes 10 floating point types. Therefore, we can control Dobot movement mode, velocity and acceleration through the 10 variables. Details are as follows:
static float cmd_str_10[10]; static unsigned char cmd_str_42[42];
// Send a 42 byte data packet to the dobot according to the communication protocol. void cmd_str_42_send() { cmd_str_42[0] = 0xA5; for( char I = 0; I < 10; I++ ) { *((float *)(cmd_str_42 + 1 + 4*I)) = float( cmd_str_10[I] ); } cmd_str_42[41] = 0x5A; for( char I = 0; I < 42; I++ ) { Serial1.write( cmd_str_42[I] ); } }
Step 2: Parameter Configuration
We need send out commands before controlling Dobot, which is used for configuration of motion parameters. Now we will configure parameters using defined arrays above. According to protocol, motion parameters are shown when state= 9, decribed as follows:
Figure 3 instruction of parameter configuration
For simplicity's sake, here we choose Axis=0, and only has a configuration of uniaxial jog velocity and uniaxial jog acceleration, the rest remains the default. Program examples follows:
//Set parameters of Dobot with state 9. void dobot_cmd_3(int mode= 0, int Joint_jog_speed=0, int Joint_jog_acc=0){ for(char i = 0; i < 10; i++ ){ cmd_str_10[i] = 0; } // refer to protocal file for detail cmd_str_10[0] = 9; cmd_str_10[1] = mode; cmd_str_10[2] = Joint_jog_speed; cmd_str_10[3] = Joint_jog_acc; cmd_str_42_send(); }
Step 3: Demo of Jog Mode
Parameters of Jog Mode below:
Figure 4 parameters instruction of jog mode
Figure 5 navigate hex file
/* ** demo that dobot controled by another Arduino MEGA 2560 ** with dobot firmware V1.2.0 ** ** connections: ** dobot side(Wireless port) | another Arduino side(UART1 port) ** GND ------ GND ** TX ------ TX1 ** RX ------ RX1 ** note: if another Arduino is self powered by USB or 12V, just connect above 3 lines is OK ** if another Arduino has no USB or 12V power, another connection between VCC ------ 5V is needed. ** ** 20160523 */
static float cmd_str_10[10]; static unsigned char cmd_str_42[42]; // Send a 42 byte data packet to the dobot according to the communication protocol. void cmd_str_42_send() { cmd_str_42[0] = 0xA5; for( char i = 0; i < 10; i++ ) { *((float *)(cmd_str_42 + 1 + 4*i)) = float( cmd_str_10[i] ); } cmd_str_42[41] = 0x5A; for( char i = 0; i < 42; i++ ) { Serial1.write( cmd_str_42[i] ); } } //Set parameters of Dobot with state 9. void dobot_cmd_3( int mode= 0, int Joint_jog_speed=0, int Joint_jog_acc=0){ for( char i = 0; i < 10; i++ ){ cmd_str_10[i] = 0; } // refer to protocal file for detail cmd_str_10[0] = 9; cmd_str_10[1] = mode; cmd_str_10[2] = Joint_jog_speed; cmd_str_10[3] = Joint_jog_acc; cmd_str_42_send(); } //Set joint jog mode with state 2. void dobot_cmd_2( int axis= 0, int StartVe= 0 ){ for( char i = 0; i < 10; i++ ){ cmd_str_10[i] = 0; } // refer to protocal file for detail cmd_str_10[0] = 2; cmd_str_10[1] = axis; cmd_str_10[7] = StartVe; cmd_str_42_send(); } void setup() { // put your setup code here, to run once: // Serial1 connected with dobot Serial1.begin(9600); } void loop() { // put your main code here, to run repeatedly: // wait dobot init... delay( 1000 ); dobot_cmd_2( 0,0); // button released dobot_cmd_3( 0,50,100); //configure the joint jog speed and the joint jog acceleration before controlling the dobot to move. // move 3 loop for( char i = 0; i < 2; i++ ){ dobot_cmd_2( 3,50); // joint1+(CCW) // here just delay a few time between two cmd send simply // for better performance, next cmd can be send out if a new frame on rxd is received delay(1000); dobot_cmd_2( 0,0);// button released delay(1000); //decelerate dobot_cmd_2( 4,50);//joint1-(CW) delay(1000); dobot_cmd_2( 0,0);// button released delay(1000); //decelerate } //end while(1); }
Program above will make base rotate back and forth three times, Similarly, select state=7, one can control Dobot coordinate jog, it is not described here.
