VoltLink™

If you would like to order one of these adapters ready assembled, check out my Tindie store.

VoltLink™ is a USB to serial adapter board based on the popular CP2102N chip with built-in ESP32 auto-reset circuitry. When compared to the cheap modules you can get from Aliexpress this adapter is reliable & flexible at the same time. Reliable because it's based on a well known usb to serial adapter chip sourced from a known supplier and flexible because you have the ESP32 IO & EN pin auto-reset circuit built-in so there is no need to implement this on the target board.

Another advantage of the VoltLink is the built-in 3.3V 500mA low dropout regulator capable of powering the device your are programming. Optionally you can connect a custom JST cable that alows programming of Shelly relays safely, without mains power. This makes the VoltLink one of the best usb/serial adapters to flash your devices with Tasmota or ESPHome.

You have the option of connecting through the VoltLink connector which is a JST-SH 1.0mm pitch 6 pin connector that saves space on the target board or via standard 0.1 inch pin header.

More info about this project in Voltlog #405.

Please note, there have been several board revisions since I made that video.