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Ble Robot Car Using Realtek Ameba Rtl8722dm (amb21) Board

Made by vinayyn / Robotics / IoT

About the project

Here I am showcasing BLE Robot Car Controlling With Bluefruit Connect App.

Project info

Difficulty: Moderate

Platforms: Adafruit, Android, Seeed Studio

Estimated time: 3 hours

License: GNU General Public License, version 3 or later (GPL3+)

Items used in this project

Hardware components

	Jumper wires (generic)	x 1
	Toggle Switch, (On)-Off-(On)	x 1
	chasis	x 1
	Wheel 10cm Diameter	x 4
	Rechargeable Battery, 12 V	x 1
	SparkFun Dual H-Bridge motor drivers L298	x 1
	Geared DC Motor, 12 V	x 4
	Ameba RTL8722DM IoT Development Board	x 1

View all

Software apps and online services

	Tape, Double Sided
	Multitool, Screwdriver
	Solder Flux, Soldering
	Solder Wire, Lead Free
	Adafruit Bluefruit Connect
	Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

x 1

Story

Introduction To Ameba RTL8722DM Board (AMB 21)

Ameba RTL8722DM IoT Development Board integrates the RTL8722DM SoC which is the latest generation SoC of the Ameba IoT solution family, and it is powered by a high-performance 32-bit dual MCU with a new architecture from Arm. an Arm v8M (Cortex-M33 instruction set compatible) running at up to 200MHz and an Arm®v8M (Cortex-M23 instruction set compatible) running at up to 20MHz.

RTL872xD is a highly integrated single-chip low power dual bands (2.4GHz and 5GHz) Wireless LAN (WLAN) and Bluetooth Low Energy (BLE 5.0) communication controller. It consists of a high-performance MCU (Armv8-M, Cortex-M33 instruction set compatible) called Real-M300 (or KM4 thereafter) and a low power MCU (Armv8-M, Cortex-M23 instruction set compatible) called Real-M200 (or KM0 thereafter), WLAN (802.11 a/b/g/n) MAC, a 1T1R capable WLAN baseband, RF, Bluetooth, and peripherals. High-speed connectivity interfaces, SDIO, and USB are provided. There are also audio codec, Key-Scan, and touch keys integrated into this IC. Besides, flexible design configures GPIO to different functions according to applications. RTL872xD also integrates memories (ROM/SRAM/PSRAM) for IoT (Internet of Things) Wi-Fi protocol functions and applications. The user-friendly development kits (SDK and HDK) are supported to customers for developing IoT applications. The KM4 MCU is a 32-bit core that offers system enhancements such as low power consumption, enhanced debug features, floating-point computation, DSP instructions, and a high level of support block integration. The KM4 MCU incorporates a 3-stage pipeline. The KM0 coprocessor is an energy-efficient and easy-to-use 32-bit core that is code- and tool-compatible with the KM4 core. The KM0 coprocessor offers up to 20MHz performance with a simple instruction set and reduced code size.

Ameba RTL8722DM Board (AMB 21)

Features

Ultra-low power consumption suitable for IoT applications
Latest high-security architecture with secure boot
Dual Arm® powered CPUs for higher performance
Fast wireless speeds with the latest wireless technologies such as Wi-Fi 5GHz and BLE5
Rich I/O peripherals to further expand your projects

CPU

32-bit Arm®Cortex®-M4, up to 200MHz.32-bit Arm®Cortex®-M0, up to 20MHz.

MEMORY

512KB SRAM + 4MB PSRAM

KEY FEATURES

Integrated 802.11a/n Wi-Fi SocTrust zone-M SecurityHardware SSL EngineRoot Trust Secure BootUSB Host/DeviceSD HostBLE5.0CodecLCDCKey Matrix

OTHER FEATURES

1 PCM interface4 UART interface1 I2S Interface2 I2C interface7 ADC17 PWMMax 54 GPIO

The wireless features of RTL872xD

Wi-Fi Features

802.11 a/b/g/n 1x1, 2.4GHz & 5GHz
Supports 20MHz/40MHz up to MCS7 l Low power architecture
Low power Tx/Rx for short-range application @1.8V
Low power beacon listen mode l Low power Rx mode
Very low power suspends mode (DLPS)
Built-in PA, also supports external PA and LNA
Supports Antenna diversity
Internal PTA interface for arbitrating data transmission between Wi-Fi and internal Bluetooth or external 2.4G devices

Bluetooth Features

BLE 5.0
Both central and peripheral modes
High power mode (8dbm, shares the same PA with Wi-Fi)
Internal co-existence mechanism between Wi-Fi and BT to share the same antenna

To Learn More About The Ameba RTL8722DM Board (AMB 21) go through this link click Here.

_______________________________________________________________

Here I am showcasing BLE Robot Car Controlling With Bluefruit Connect App

Working Of BLE Robot Car Controlling With Bluefruit Connect App

I am controlling a robot car using the Bluefruit connect app. The app sends the Particular commands when I press the control pad on the app. on the receiver side, I have used Realtek Ameba RTL8722DM (AMB21) Board. The RTL8722DM receives the Bluetooth data and processes the received data and sends the Contro signal to the Motor Driver. The motor Driver Controls the Four motors according to the control signals.

Block Diagram of the project

BLE Robot Car

Demo Video

Demo Video

Useful Links

1. https://www.amebaiot.com/en/rtl8722dm-arduino-online-api-documents/

2.https://www.amebaiot.com/en/

Schematics, diagrams and documents

Connection diagram

Code

The code is based on C

#include "BLEDevice.h"
const int ml1 = 3; //Motor Driver IN1
const int ml2 = 4; //Motor Driver IN2
const int mr1 = 5; //Motor Driver IN3
const int mr2 = 6; //Motor Driver IN4

#define UART_SERVICE_UUID      "6E400001-B5A3-F393-E0A9-E50E24DCCA9E"
#define CHARACTERISTIC_UUID_RX "6E400002-B5A3-F393-E0A9-E50E24DCCA9E"
#define CHARACTERISTIC_UUID_TX "6E400003-B5A3-F393-E0A9-E50E24DCCA9E"

#define STRING_BUF_SIZE 1000

BLEService UartService(UART_SERVICE_UUID);
BLECharacteristic Rx(CHARACTERISTIC_UUID_RX);
BLECharacteristic Tx(CHARACTERISTIC_UUID_TX);
BLEAdvertData advdata;
BLEAdvertData scndata;
bool notify = false;

void readCB (BLECharacteristic* chr, uint8_t connID) {
  printf("Characteristic %s read by connection %d \n", chr->getUUID().str(), connID);
}

void writeCB (BLECharacteristic* chr, uint8_t connID) {
  printf("Characteristic %s write by connection %d :\n", chr->getUUID().str(), connID);
  uint16_t datalen = chr->getDataLen();
  if (datalen > 0) {
    if (chr->readData8() == '!') {
      uint8_t command[datalen];
      chr->getData(command, datalen);
      
 // " B"  IS PREFIX TO IDENTIFY THAT RECEIVED DATA IS CONTROL PAD DATA FROM THE BLUEFRUIT APP    
 
      if (command[1] == 'B') 
      { 
        Serial.print("Command 2:");
        Serial.print(command[2]);
        Serial.println();
        Serial.print("Command 3:");
        Serial.print(command[3]);
        Serial.println();
        Serial.print("Command 4:");
        Serial.print(command[4]);
        Serial.println();
        
        if((command[4] == 54) && (command[3] == 49)) //FORWARD COMMAND
        {
          Serial.println("forward");
          digitalWrite(ml1, HIGH);
          digitalWrite(ml2,LOW);
          digitalWrite(mr1,HIGH);
          digitalWrite(mr2,LOW);
        }
         if((command[4] == 55) && (command[3] == 48))//STOP COMMAND 
        {
          Serial.println("STOP");
          digitalWrite(ml1, HIGH);
          digitalWrite(ml2,HIGH);
          digitalWrite(mr1,HIGH);
          digitalWrite(mr2,HIGH);
        }

       
      if((command[4] == 53) && (command[3] == 49))//REVERSE COMMAND
        {
          Serial.println("Reverse");
          digitalWrite(ml1, LOW);//REVERS
          digitalWrite(ml2,HIGH);
          digitalWrite(mr1,LOW);
          digitalWrite(mr2,HIGH);
        }
if((command[4] == 54) && (command[3] == 48))//STOP COMMAND 
        {
          Serial.println("STOP");
          digitalWrite(ml1, HIGH);
          digitalWrite(ml2,HIGH);
          digitalWrite(mr1,HIGH);
          digitalWrite(mr2,HIGH);
        }

      
         if((command[4] == 52) && (command[3] == 49))//LEFT COMMAND
        { 
          Serial.println("LEFT");
          digitalWrite(ml1, HIGH);//LEFT
          digitalWrite(ml2,LOW);
          digitalWrite(mr1,HIGH);
          digitalWrite(mr2,HIGH);
        }
          if((command[4] == 53) && (command[3] == 48))//STOP COMMAND 
        { 
          Serial.println("STOP");
          digitalWrite(ml1,HIGH);
          digitalWrite(ml2,HIGH);
          digitalWrite(mr1,HIGH);
          digitalWrite(mr2,HIGH);
        }

        
         if((command[4] == 51) && (command[3] == 49))//RIGHT COMMAND
        {
          Serial.println("RIGHT");
          digitalWrite(ml1, HIGH);
          digitalWrite(ml2,HIGH);
          digitalWrite(mr1,HIGH);
          digitalWrite(mr2,LOW);
        }
        if((command[4] == 52) && (command[3] == 48))//STOP COMMAND 
        {
          Serial.println("STOP");
          digitalWrite(ml1, HIGH);
          digitalWrite(ml2,HIGH);
          digitalWrite(mr1,HIGH);
          digitalWrite(mr2,HIGH);
        }
        
delay(100);
      }
    } else {
                  Serial.print("Received string: ");
                  Serial.print(chr->readString());
                  Serial.println();
    }
  }

void notifCB (BLECharacteristic* chr, uint8_t connID, uint16_t cccd) {
  if (cccd & GATT_CLIENT_CHAR_CONFIG_NOTIFY) {
    printf("Notifications enabled on Characteristic %s for connection %d \n", chr->getUUID().str(), connID);
    notify = true;
  } else {
    printf("Notifications disabled on Characteristic %s for connection %d \n", chr->getUUID().str(), connID);
    notify = false;
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(ml1, OUTPUT);
  pinMode(ml2,OUTPUT);
  pinMode(mr1, OUTPUT);
  pinMode(mr2,OUTPUT);
  advdata.addFlags(GAP_ADTYPE_FLAGS_LIMITED | GAP_ADTYPE_FLAGS_BREDR_NOT_SUPPORTED);
  advdata.addCompleteName("AMEBA_BLE_DEV");
  scndata.addCompleteServices(BLEUUID(UART_SERVICE_UUID));

  Rx.setWriteProperty(true);
  Rx.setWriteCallback(writeCB);
  Rx.setBufferLen(STRING_BUF_SIZE);
  Tx.setReadProperty(true);
  Tx.setReadCallback(readCB);
  Tx.setNotifyProperty(true);
  Tx.setCCCDCallback(notifCB);
  Tx.setBufferLen(STRING_BUF_SIZE);

  UartService.addCharacteristic(Rx);
  UartService.addCharacteristic(Tx);

  BLE.init();
  BLE.configAdvert()->setAdvData(advdata);
  BLE.configAdvert()->setScanRspData(scndata);
  BLE.configServer(1);
  BLE.addService(UartService);

  BLE.beginPeripheral();
}

void loop() {
  if (Serial.available()) {
    Tx.writeString(Serial.readString());
    if (BLE.connected(0) && notify) {
      Tx.notify(0);
    }
  }
  delay(100);
}

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Ble Robot Car Using Realtek Ameba Rtl8722dm (amb21) Board

About the project

Project info