Luteijn/Vortex

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Revision as of 07:32, 1 February 2018 by Luteijn (talk | contribs) (Eyes)
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Project "Vortex":

Project Luteijn/Vortex
Vortex 1.jpg
Status In progress
Contact Luteijn
Last Update 2018-02-01

I've got four DFRobot 'Vortex' units. Basic programming via the official apps is possible, but rather limited. The WhenDo app is only available on iPad. Luckily, the internal Arduino clone can be directly programmed too. Unfortunately, not all the specs seem to be available, but there are some examples to work with, although they have a quite a bit of 'magic numbers' in them. These examples might disappear, so duplicating them here, with my own notes as available. The examples-coding is mostly done by "Andy Zhou <Andy.zhou@dfrobot.com>", although I did change some of the things to figure out what they do.

http://wiki.dfrobot.com.cn/index.php?title=(SKU:ROB0116)_Vortex%E5%8F%AF%E7%BC%96%E7%A8%8B%E6%9C%BA%E5%99%A8%E4%BA%BA#.E6.A0.B7.E4.BE.8B.E4.BB.A3.E7.A0.81

https://www.dfrobot.com/wiki/index.php/Vortex_Arduino_Coding_Tutorial_V1.0#Introduction

(Chinese page seems to have a bit better documentation, although English page might be easier to read and it is interesting to compare the differences)

http://wiki.dfrobot.com.cn/images/1/10/%E4%B8%BB%E6%9D%BF.png

What's connected to the pins

Connection overview
0 Serial RX (input)
1 Serial TX (output)
2 Encoder Wheel (External Interrupt 0) (input)
3 Encoder Wheel (External Interrupt 1) (input)
4 ?? mp3 RX (input) hopefully but don't know. Doesn't seem to be it. Also not head closed sensor (which seems to be straight reed switch for power to top leds)
5 Motor 0 Speed (PWM) (outp```ut)
6 Motor 1 Speed (PWM) (output)
7 IR decoder/detector (input)
8 IR led Left (output)
9 Motor 0 direction (H=forwards,L=reverse) (output)
10 Motor 1 direction (output)
11 MP3-player TX (output)
12 IR led Right (output)
13 GRB LED chain around body (output)
A0 grayscale 4 'D' (input)
A1 grayscale 3 'C' (input)
A2 grayscale 2 'B' (input)
A3 grayscale 1 'A' (input)
A4 SDA (i2c)
A5 SCL (i2c)
A6 grayscale 5 'E' (input)
A7 grayscale 6 'F' (input)

i2c bus + Vcc & Vdd should be available at 4 pin rear expansion port too

Motor Control

Simple 'enable' and 'direction' pins for left and right wheels. Enable can be PWM'd or just full on. This example revs up the engines with PWM.

int E1 = 5;                                                                                         
int M1 = 9;                                                                                         
int E2 = 6;                                                                                         
int M2 = 10;                                                                                        
                                                                                                    
void setup()                                                                                        
{                                                                                                   
  pinMode(M1, OUTPUT); // directional controls, High is forward, Low is backward                                                                             
  pinMode(M2, OUTPUT);                                                                              
}                                                                                                   
                                                                                                    
void loop()                                                                                         
{                                                                                                   
  int value;                                                                                        
  for(value = 0 ; value <= 255; value+=5)    //foreward                                             
  {                                                                                                 
    digitalWrite(M1,HIGH);                                                                          
    digitalWrite(M2, HIGH);                                                                         
    analogWrite(E1, value);   //PWM Speed control                                                   
    analogWrite(E2, value);   //PWM Speed Control                                                   
    delay(30);                                                                                      
  }                                                                                                 
                                                                                                    
  for(value = 0 ; value <= 255; value+=5)   //backward                                              
  {                                                                                                 
    digitalWrite(M1, LOW);                                                                          
    digitalWrite(M2, LOW);                                                                          
    analogWrite(E1, value);   //PWM Speed control                                                   
    analogWrite(E2, value);   //PWM Speed Control                                                   
    delay(30);                                                                                      
  }                                                                                                 
}                                                    

Encoders

The two external interrupts are linked to encoders that track wheel movement, so it is possible to detect the Vortext is being pushed/pulled/turned, although I don't think these things indicate which direction the robot is pushed in...

#define pinInputLeft 0 // this is the interrupt, not the pin number, D2
#define pinInputRight 1 // external int 1, D3
long leftPul,rightPul;

void leftCallBack(){
  leftPul++;
}

void rightCallBack(){
  rightPul++;
}

void initDdevice(){
    pinMode(5,OUTPUT);
    pinMode(6,OUTPUT);
    pinMode(9,OUTPUT);
    pinMode(10,OUTPUT);
    noInterrupts();
    attachInterrupt(pinInputLeft,leftCallBack,CHANGE);
    attachInterrupt(pinInputRight,rightCallBack,CHANGE);
    interrupts();
}

void motorDebug(){
  digitalWrite(5,HIGH);
  digitalWrite(6,HIGH);
  digitalWrite(9,HIGH);
  digitalWrite(10,HIGH);
}

void printPul(){
  Serial.print(leftPul);
  Serial.print(" ");
  Serial.println(rightPul);
  leftPul = 0;
  rightPul = 0;
}

void setup() {
  initDdevice();
  Serial.begin(9600);
  motorDebug();
}

void loop() {
  printPul();
  delay(500);
}

Analogue Inputs

six 'grayscale' detectors are placed around the bottom of the Vortex, to be used to track a line, maybe read simple codes from the floor.

 
       2 (a2) 3 (a1)  
1 (a3)               4 (a0)




5 (a6)               6 (a7)

This is the example sketch to dump the values read by the 6 little eyes.

void setup(void){
 Serial.begin(9600); 
}

int analogBuf[6] = {'\0'};

void loop(void){
  analogBuf[0] = analogRead(3);
  analogBuf[1] = analogRead(2);
  analogBuf[2] = analogRead(1);
  analogBuf[3] = analogRead(0);
  analogBuf[4] = analogRead(6);
  analogBuf[5] = analogRead(7);
  for(int i=0;i<6;i++){
    Serial.print(i+1);
    Serial.print(": ");
    Serial.print(analogBuf[i]);
    Serial.print("   ");
  }
  Serial.println();
  delay(500);
}

Wonder what's connected to A4 and A5, if anything? These are used for the i2c bus! See below under the Luteijn/Vortex#Eyes section

LEDs

12 RGB (GRB!) leds can be addressed. Example from website causes Red and Green to be swapped. initialize library differently:

  FastLED.addLeds<WS2811, DATA_PIN, GRB>(leds, NUM_LEDS);                                           

IR example below uses some of the LED functionality.

IR obstacle detector

Seems to be somewhat flaky. Needs a bit more work to figure out. Also, the IR sensor might be useful to read IR remote controllers or beacons. This receiver seems to work at 38kHz, but probabbly also reacts to 36-40kHz. Remote controllers often work at 36kHz. Note that 2x 8µs delay doesn't give you 38kHz, but the digitalWrite itself also induces quite some delay (3-6µs), so seems this is bringing the total period up to around the 26.something µs we'd expect.


#define NUM_LEDS 12                                                                                 
                                                                                                    
// Data pin that led data will be written out over                                                  
#define DATA_PIN 13                                                                                 
CRGB leds[NUM_LEDS];                                                                                
                                                                                                    
#define IR_IN  7//IR receiver pin                                                                   
#define L_IR 8  //left ir transmitter pin                                                           
#define R_IR 12 //right ir transmitter pin                                                          
                                                                                                    
int count;                                                                                          
                                                                                                    
void leftSend38KHZ(void){//left ir transmitter sends 38kHZ pulse                                    
  int i;                                                                                            
  for(i=0;i<24;i++){                                                                                
    digitalWrite(L_IR,LOW);                                                                         
    delayMicroseconds(8);                                                                           
    digitalWrite(L_IR,HIGH);                                                                        
    delayMicroseconds(8);                                                                           
  }                                                                                                 
}                                                                                                   
void rightSend38KHZ(void){//right ir transmitter sends 38kHZ pulse                                  
  int i;                                                                                            
  for(i=0;i<24;i++){                                                                                
    digitalWrite(R_IR,LOW);                                                                         
    delayMicroseconds(8);                                                                           
    digitalWrite(R_IR,HIGH);                                                                        
    delayMicroseconds(8);                                                                           
  }                                                                                                 
}                                                                                                   
                                                                                                    
void pcint0Init(void){//init the interrupt                                                          
    PCICR |= 1 << PCIE2;                                                                            
    PCMSK2 |= 1 << PCINT23; //pin D7 is int23                                                       
}                                                                                                   
                                                                                                    
ISR(PCINT2_vect){//IR decoder interrupt                                                             
  count++;                                                                                          
}                                                                                                   
                                                                                                    
void obstacleAvoidance(void){                                                                       
  char i;                                                                                           
  count=0;                                                                                          
   leds[5] = CRGB::Green;                                                                           
   FastLED.show();                                                                                  
  for(i=0;i<20;i++){  //left transmitter sends 20 pulses                                            
    leftSend38KHZ();                                                                                
    delayMicroseconds(600);                                                                         
  }                                                                                                 
  if(count>10){//if received a lot pulse , it means there's a obstacle                              
    leds[5] = CRGB::White;                                                                          
    FastLED.show();                                                                                 
    Serial.println("Left");                                                                         
    delay(100);                                                                                     
  }                                                                                                 
  count=0;                                                                                          
  leds[3] = CRGB::Green;                                                                            
  FastLED.show();                                                                                   
  for(i=0;i<20;i++){//right transmitter sends 20 pulses                                             
    rightSend38KHZ();                                                                               
    delayMicroseconds(600);                                                                         
  }                                                                                                 
  if(count>10){//if received a lot pulse , it means there's a obstacle                              
    leds[3] = CRGB::White;                                                                          
    FastLED.show();                                                                                 
    Serial.println("Right");                                                                        
    delay(100);                                                                                     
  }                                                                                                 
  delay(600);                                                                                       
}                                                                                                   
                                                                                                    
void setup(void){                                                                                   
  delay(2000);                                                                                      
  FastLED.addLeds<WS2811, DATA_PIN, GRB>(leds, NUM_LEDS);                                           
  pinMode(L_IR,OUTPUT);//init the left transmitter pin                                              
  pinMode(R_IR,OUTPUT);//init the right transmitter pin                                             
  pinMode(IR_IN,INPUT);//init the ir receiver pin                                                   
  Serial.begin(9600);                                                                               
  leds[4] = CRGB::Blue;                                                                             
  FastLED.show();                                                                                   
  delay(2000);                                                                                      
  leds[4] = CRGB::Purple;                                                                           
  FastLED.show();                                                                                   
  noInterrupts();                                                                                   
  pcint0Init();                                                                                     
  interrupts();             //enable the interrupt                                                  
}                                                                                                   
                                                                                                    
void loop(void){                                                                                    
    obstacleAvoidance();                                                                            
}

IRreceiver

Since DFrobot also have a 'loose' IR-receiver module in their program, decided to just see if the example sketches for those would transfer, and they do. https://www.dfrobot.com/product-366.html - A remote similar to the one pictured on the DFRobot product page actually came with one of my RTLSDR sticks, and seems to work well enough, although the range isn't great, couple of meters. With a 'proper' remote control, e.g. from a TV, the range is fine, 10m at least when pointing at unit from across the house. Might be less if using reflections to try to control a roving robot.

So, using the IRremote library you can read values from a remote controller:

#include "IRremote.h"
#define IR_IN  7//IR receiver pin
IRrecv irrecv(IR_IN);
decode_results results;

void setup(void){
  Serial.begin(9600);                                                                               
  irrecv.enableIRIn(); // Start the receiver
}                                                                                                   

void loop(void){                                                                                    
  if (irrecv.decode(&results)) {                                                                    
    Serial.println(results.value, HEX);                                                             
    irrecv.resume(); // Receive the next value
  }                                                                                                 
} 

This was already useful to read codes from the remote of the AV-receiver we have at home and then play these back via a universal remote app on the smartphone that was missing some buttons. For some reason I couldn't find the 'learn' function in the app, but could enter the codes as read by this sketch easily.

MP3-player

There is an MP3.player integrated in the robot. It can be controlled by sending more or less magic commands over software Serial via pin 11. Pin 2 might be connected to the player too if the example I found can be believed, but my tests so far never had anything received there, or on pin 4. Would be nice to get an 'end of song reached' or to get things like version information out. Anyway, Pin 2 is connected to one of the wheel encoders, so not likely to be the RX. It might also be co-connected to one of the relatively harmless outputs, like to the ir emitter? Will need to trace the board to find out, but initial quick look didn't immediately show anything.

The example found on the DFRobot site:

#define MP3_VOLUME 0x10
#define TX 11
#define RX 4  // ?? was 2 in example I found, but that is unlikely
#include <SoftwareSerial.h>

SoftwareSerial mySerial(RX, TX);// RX, TX
void setup()
{
  delay(1000); 
  mp3Init();
  mp3setVolume(30);//0~255
}
void loop()
{
  mp3player(1);
  delay(2000);
  mp3stop();
  delay(1000);
}
void mp3Init()
{
    mySerial.begin (9600);
}
void mp3setVolume(byte vol)
{
    uint8_t buffer[] = {0x7e, 0xff, 0x06, 0x06, 0x00, 0x00, vol, 0xef};
    mySerial.write(buffer, 8);
    delay(20);
}
void mp3player(byte data)
{
    uint8_t buffer[] = {0x7e, 0xff, 0x06, 0x03, 0x00, 0x00, data, 0xef};
    mySerial.write(buffer, 8);
    delay(20);
}

void mp3stop()
{
    uint8_t buffer[] = {0x7e, 0xff, 0x06, 0x16, 0x00, 0x00, 0x00, 0xef};
    mySerial.write(buffer, 8);
}

The files to play can be put on the Vortex via usb, seems the little switch next to the micro-usb socket switches this between the mp3-players mass-storage and the arduino usb-serial interface. The number passed to the player is just the index into the (FAT?) table of stored songs. So, be careful of the order these are uploaded to the memory in.

https://www.dfrobot.com/product-1121.html , documented at https://www.dfrobot.com/wiki/index.php/DFPlayer_Mini_SKU:DFR0299 is a mini-MP3 player from DFRobot. It is controllable over serial, and might be the same one as used in the Vortex. Would be good to figure out if the 'busy' signal and/or the serial TX are connected back to the arduino somewhere in that case. Player could also be a variant but the magic numbers more or less match (although the stop command 0x16 is not in the table. Perhaps Dec16 / 0x0A (standby/low power mode) was meant? The MP3-chip Part# is YX6100-24SS. Seems to be part of a family of serial MP3-players.

Documentation for the DFRobot miniplayer mentions the instruction format to be:

Format: $S VER Len CMD Feedback para1 para2 checksum $O
$S Start byte 0x7e Each command begins with 0x7e ('~')
VER Version information Version seems to be 0xff from the example
Len the number of bytes Start, End and Checksum are not counted,
CMD Commands See command table.
Feedback Command feedback 1: feedback, 0: no feedback ; need to test what this does, might mean 'echo'
Para1 Parameter 1 Query high data byte
Para2 Parameter 2 Query low data byte
checksum Checksum accumulation and verification, doesn't include start byte. Seems to be 2 bytes from the example given in the docs, but Vortex seems to just not need it put in. example given is 7e ff 06 09 00 00 04 ff dd ef
$O End byte End of command is signaled with 0xEF
Command table WIP to copy this over

Code to calculate the checksum from the Library supporting the miniplayer:

uint16_t DFRobotDFPlayerMini::calculateCheckSum(uint8_t *buffer){
  uint16_t sum = 0;
  for (int i=Stack_Version; i<Stack_CheckSum; i++) {
    sum += buffer[i];
  }
  return -sum;
}

but this doesn't seem to be needed.

Eyes

Besides 35 predefined eye patterns, it is also possible to upload your own eye patterns.

The default eyes can be set as follows:

#include <Wire.h>
#define I2C_LED_ADDRESS 0b1100000
#define I2C_WRITE   0x00

uint8_t serial=0;

void setup(){
   Wire.begin(); // join i2c bus (address optional for master)
   defined_eyes(6,1);                                                                               
   delay(2000);
}
void loop(){
   defined_eyes(1,serial); 
   serial++;                                                                                        
   if(serial>=35) serial=0;                                                                         
   delay(250);                                                                                      
}


void defined_eyes(uint8_t color,uint8_t serial) {

   Wire.beginTransmission(I2C_LED_ADDRESS << 1 | I2C_WRITE); // transmit to device #4
   Wire.write(color&0x07); // color bits: 1 blue, 2 green, 4 red 
   Wire.write(serial);  //preset eyes 0~34
   Wire.endTransmission();    // stop transmitting                                                  
}

void custom_eyes(uint8_t color, uint8_t eyeline[10]){
   uint8_t index;
   // right eye         left eye
   //1  2  3  4  5      25 24 23 22 21                                                              
   //6  7  8  9  10     20 19 18 17 16                                                              
   //11 12 13 14 15     15 14 13 12 11                                                              
   //16 17 18 19 20     10 9  8  7  6
   //21 22 23 24 25     5  4  3  2  1                                                               
   Wire.beginTransmission(I2C_LED_ADDRESS << 1 | I2C_WRITE); // transmit to device #4
   Wire.write(0x55);  // color 55=custom eyes follow 
   Wire.write(0xAA);  // ?? AA=color followed by 10 bytes, each defining one line
                      // other values cause eyes to light up in multiple colors, needs more work

   Wire.write(color&0x7);         //color 1-B,2-G,4-R of foreground
                                                                                                    
   for (index=0;index<10;index++) {
     Wire.write(eyeline[index]);
   }                                                                                                
   Wire.endTransmission();    // stop transmitting   


void example_eyes() {
   /* left eye of robot (right for onlooker) */
   Wire.write(0x1f); // bottom row, all bits lit
   Wire.write(0x1e); // 10 9 8 7 on, 6 off
   Wire.write(0x1c);
   Wire.write(0x18);
   Wire.write(0x10);
                                                                                                    
   /* right eye of robot (left for onlooker) */
   Wire.write(0x1f);  // top row all 5 bits lit
   Wire.write(0x0f);  // leds 6,7,8,9 on 10 off
   Wire.write(0x07);  // 11,12,13 on,  14,15 off                         
   Wire.write(0x03);                                                                                
   Wire.write(0x01);                                                                                
}                        

i2c

There might be more stuff connected to the i2c already, I plan to do some tests to find out. Would be nice if e.g. the flash of the mp3 player or some other expansion was already there.

Regardless of what's there already, Vortex seems to be designed to be extended over i2c, and could be a nice platform to do some experiments/demo's with. WIP :)