ESP8266 Programmer

For the software side of some ESP8266 development, I bought a cheap ESP01 to USB adapter from AliExpress, expecting a programming adapter. What turned up on my doorstep, however, was just a USB-UART adapter which wasn’t able to drive the reset and GPIO0 pins. Luckily, the missing circuitry could be added easily.

The bodge’s schematic is based on the NodeMCU DEVKIT. The PCB uses a different USB-UART bridge IC but DTR and RTS are available as well.
I soldered the four resistors and two transistors directly to the female header. A drop of glue stabilises the hanging side of the circuit.
The CH340G’s DTR and RTS pins weren’t connected to anything else and I could route the signals with some enamelled wire through a small notch directly to the pins.
Published 2020-01-18 in #ESP8266. Last updated 2024-08-18.