Install Arduino IDE 2.0 beta on Linux Mint 20.1, include ESP32/ESP8266 support.

Arduino IDE 2.0 (beta) is now available (refer to announcement in Arduino blog). It,s my first try to install Arduino IDE 2.0 beta (2.0.0-beta3) on Linux Mint 20.1, tested with VirtualBox 6.1/Windows 10.

Download Arduino IDE 2.0 beta

Visit https://www.arduino.cc/en/software, scroll download to download Arduino IDE 2.0 beta for Linux 64 bits (X86-64).

Run arduino-ide

Extract the downloaded file to a any folder you want. Run arduino-ide in Terminal
$ ./arduino-ide

Install board

In a fresh new installed Arduino IDE 2.0, no board is installed, you will be report with error:

Compilation error: Error: 2 UNKNOWN: platform not installed

Click Boards Manager on left, search to install Arduino AVR Boards by Arduino.

Add permission to user, to access USB

In a new Linux, you (as a regular user) have no permission to access USB port, and report with error:

avrdude: ser_open(): can't open device "/dev/ttyACM0": Permission denied

Open Terminal, enter the command to add permission:
$ sudo usermod -a -G dialout <username>
$ sudo chmod a+rw <port>

Done.

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Install board support for ESP32/ESP8266

Menu > File> Preferences

Enter the url in the "Additional Board Manager URLs":

https://dl.espressif.com/dl/package_esp32_index.json (for ESP32)

http://arduino.esp8266.com/stable/package_esp8266com_index.json (for ESP8266)

Then you can add board of ESP32/ESP8266 in Boards Manager.

Setup Python

By default Linux Mint 20.1 pre-install Python3, but no Python2. Currently, esptool for ESPs call python. You can create a symlinks /usr/bin/python to python3 by installing python-is-python3.

$ sudo apt install python-is-python3

Optionally, you can prevent Python 2 from being installed as a dependency of something in the future:

$ sudo apt-mark hold python2 python2-minimal python2.7 python2.7-minimal libpython2-stdlib libpython2.7-minimal libpython2.7-stdlib

And you have to install pyserial with pip:

$ sudo apt install python3-pip

$ pip3 install pyserial

Add permission to your user (if not do in above steps):

Additionally, if you cannot download your code to board caused by:

avrdude: ser_open(): can't open device "/dev/xxx": Permission denied

$ sudo usermod -a -G dialout <username>

$ sudo chmod a+rw <port>

ESP32 drive NeoPixel using Adafruit_NeoPixel library

ESP32 (ESP32-DevKitC V4) code in Arduino Framework to drive a 8X NeoPixel Ring using Adafruit_NeoPixel library simple example.

In Arduino IDE library manager, install Adafruit_NeoPixel library.

Open Example > Adafruit_NeoPixel > simple

Edit PIN on the Arduino is connected to the NeoPixels, and number of NeoPixels are attached.

 Connect NexPixel to ESP32 accordingly, verify and upload your code to run:

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Note that if you assign PIN to a wrong pin, such as input only. Error message will be output to Serial:

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~ more examples of ESP32-DevKitC V4

BLE Notification example: ESP32 BLE server read analog input and notify connected device

Code run on ESP32-DevKitC V4 (Arduino framework), to act as BLE server. Once connected, it read Analog Input and notify connected device.

It's modified from last post of ESP32 BLE_notify example.

The client side is programmed using Python run on Raspberry Pi, handle the notification and plot the value graphically.

BLE_notify_AIN.ino

#include <BLEDevice.h>
#include <BLEServer.h>
#include <BLEUtils.h>
#include <BLE2902.h>

#define PinAnalogIn 36

BLEServer* pServer = NULL;
BLECharacteristic* pCharacteristic = NULL;
bool deviceConnected = false;
bool oldDeviceConnected = false;
uint32_t value = 0;

// See the following for generating UUIDs:
// https://www.uuidgenerator.net/

#define SERVICE_UUID        "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
#define CHARACTERISTIC_UUID "beb5483e-36e1-4688-b7f5-ea07361b26a8"

bool rqsNotify;
unsigned long prvMillis;
#define INTERVAL_READ 1000
int valNotify;
#define MAX_VALNOTIFY 255

int ain = 0;

class MyServerCallbacks: public BLEServerCallbacks {
    void onConnect(BLEServer* pServer) {
      deviceConnected = true;

      rqsNotify = false;
      prvMillis = millis();
      Serial.println("Device connected");
    };

    void onDisconnect(BLEServer* pServer) {
      deviceConnected = false;
      rqsNotify = false;
      Serial.println("Device disconnected");
    }
};

void prcRead(){
  if(deviceConnected){
    unsigned long curMillis = millis();
    if((curMillis-prvMillis) >= INTERVAL_READ){
      int valAIO = analogRead(PinAnalogIn);
      valNotify = map(valAIO, 0, 4096, 0, 255);
      Serial.println(valNotify);
      
      rqsNotify = true;
      prvMillis = curMillis;
    }
  }
  
}


void setup() {
  Serial.begin(115200);

  // Create the BLE Device
  BLEDevice::init("ESP32");

  // Create the BLE Server
  pServer = BLEDevice::createServer();
  pServer->setCallbacks(new MyServerCallbacks());

  // Create the BLE Service
  BLEService *pService = pServer->createService(SERVICE_UUID);

  // Create a BLE Characteristic
  pCharacteristic = pService->createCharacteristic(
                      CHARACTERISTIC_UUID,
                      BLECharacteristic::PROPERTY_READ   |
                      BLECharacteristic::PROPERTY_WRITE  |
                      BLECharacteristic::PROPERTY_NOTIFY |
                      BLECharacteristic::PROPERTY_INDICATE
                    );

  // Create a BLE Descriptor
  pCharacteristic->addDescriptor(new BLE2902());

  // Start the service
  pService->start();

  // Start advertising
  BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
  pAdvertising->addServiceUUID(SERVICE_UUID);
  pAdvertising->setScanResponse(false);
  pAdvertising->setMinPreferred(0x0);  // set value to 0x00 to not advertise this parameter
  BLEDevice::startAdvertising();
  Serial.println("Waiting a client connection to notify...");

  
}

void loop() {
    // notify changed value
    if (deviceConnected) {
        if(rqsNotify){
          rqsNotify = false;
          //pCharacteristic->setValue((uint8_t*)valNotify, 1);
          //pCharacteristic->notify();

          value = valNotify;

          pCharacteristic->setValue((uint8_t*)&value, 4);
          pCharacteristic->notify();
          //value++;
          
        }
    }
    // disconnecting
    if (!deviceConnected && oldDeviceConnected) {
        delay(500); // give the bluetooth stack the chance to get things ready
        pServer->startAdvertising(); // restart advertising
        Serial.println("start advertising");
        oldDeviceConnected = deviceConnected;
    }
    // connecting
    if (deviceConnected && !oldDeviceConnected) {
        // do stuff here on connecting
        oldDeviceConnected = deviceConnected;
    }

    prcRead();
}