http://arduino.esp8266.com/stable/package_esp8266com_index.json
**Espressif ESP32**
https://dl.espressif.com/dl/package_esp32_index.json
**Heltec ESP32 Boards**
https://github.com/Heltec-Aaron-Lee/WiFi_Kit_series/releases/download/0.0.7/package_heltec_esp32_index.json
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