Record player built with NodeMCU, ESP8266, PN532, and the Spotify Web API.

• NodeMCU ESP8266 V3
• PN532 NFC Module
• Mifare Classic 1K NFC Cards

• Make sure the PN532 module is in SPI mode, this can be configured through the switches on the board

• Download the ESP8266 module libraries following the instructions in the esp8266/Arduino repository
• Download the PN532 module libraries following the elechouse/PN532 getting started guide
• In the Arduino board configuration, select the NodeMCU 1.0 (ESP-12E Module) board
• Select the correct serial port where the microcontroller is connected to

• Create a Spotify application following the steps in the Spotify developer documentation
• Set the application's Redirect URI setting to http://<YOUR_BOARD_IP_ADDRESS>/oauth/spotify
  • This can be set after loading the program into the microcontroller and which connects it to the WiFi network and its IP address can be determined
• Take note of the application's Client ID and Client Secret values

Copy secrets.example.txt into secrets.cpp, and set the values for these variables:

• OAUTH_CLIENT_ID and OAUTH_CLIENT_SECRET
  • The Client ID and Client Secret values of the Spotify application
• OAUTH_REDIRECT_URL
  • Set to http://<YOUR_BOARD_IP_ADDRESS>/oauth/spotify and should match the Redirect URI value of the Spotify application
• WIFI_SSID and WIFI_PASSWORD
  • The WiFi network's name and password
• NFC_AUTHENTICATION_KEY (Optional)
  • If you are using custom authentication keys for the NFC cards, set them here, otherwise these are set to a default value
• CA_CERTIFICATE
  • These is the root CA certificate to verify the OAuth endpoints' SSL certificate
  • To obtain these values for the Spotify APIs, run this command and copy the certificate in the output into this variable

    openssl s_client -connect accounts.spotify.com:443 -showcerts

    // secrets.cpp
    String CA_CERTIFICATE = R"CERT(
    -----BEGIN CERTIFICATE-----
    <CERTIFICATE_BODY_HERE>
    -----END CERTIFICATE-----
    )CERT";

• Connect the NodeMCU microcontroller to your computer
• Compile the code in iot-record-player.ino and upload it to the microcontroller

• Once the code has been uploaded and running in the microcontroller, visit http://<YOUR_BOARD_IP_ADDRESS> on your browser
• This performs an OAuth flow with the Spotify application to get access tokens that can be used to send requests to the Spotify API
  • After completing the OAuth flow, it's now ready to scan NFC cards and play its corresponding album/playlist on Spotify

• This project supports only Mifare Classic 1K NFC cards (4 bytes UID)
• The NFC cards need to store the Spotify context URI of the album or playlist
  • Example: spotify:album:1A3nVEWRJ8yvlPzawHI1pQ
• The NFC cards should store data starting at block number 4 in its storage memory, this project will start reading data from block number 4 until it encounters a 0xff byte
  • The writeNfcData function in nfc.cpp can be used to write data to the correct location in the NFC cards