Here is the step-by-step on upgrade the ESP-01 AT Command firmware (for running on macOS).
For flashing the ESP-01 firmware, you need to have a USB-TTl adaptor as a programmer.
| | RxD Vcc |
| Top View | IO2 RST |
| | IO0 CPD |
| | GND TxD |
ESP-01 USB-TTL Adaptor
VCC ---------- 3V3
GND ---------- GND
TxD ---------- RxD
RxD ---------- TxD
CH_PD ---------- see note* below
GPIO0 ---------- Connect to a push switch (Flash button) to GND
RST ---------- a push switch (Reset button) to GND
Note: depend on whether you have ESP-01 or ESP-01S, for ESP-01, you will need to connect CH_PD either directly to 3v3 or via a 3k-10k resistor to 3v3. However, you don't need the an extra pull-up resistor for ESP-01S as CH_PD already has on-board pull-up resistor. This picture shows the different between ESP-01 and ESP-01S, visually ESP-01 has 2 LEDs on board near the antenna, while ESP-01S have two extra resistor between header pins and ESP8266EX chip, and with only one LED.
Download and install esptool
Download and install esptool from https://github.com/espressif/esptool.
esptool is a python application. You need to have python installed as well.
Download firmware 2.1
Download ESP8266 nonOS SDK - Release 2.1.x, noticed that this is not the latest version as the latest version doesn't works for ESP-01 based on my experience.
Upgrade the firmware
You will actually only need 4 files for the upgrade, I would suggest that you copy and paste those files into your esptool directory from the downloaded
cd into your esptool directory and run the following commands to upgrade the firmware.
To put ESP-01 into programming mode:
1) Press and hold BOTH buttons;
2) Release the Reset button while keep holding the Flash button until the upload is completed;
3) Press Reset to start the newly uploaded program when all upgrades are done.
./esptool.py --port /dev/cu.SLAB_USBtoUART write_flash 0x00000 boot_v1.7.bin
./esptool.py --port /dev/cu.SLAB_USBtoUART write_flash 0x01000 user1.1024.new.2.bin
./esptool.py --port /dev/cu.SLAB_USBtoUART write_flash 0x7c000 esp_init_data_default.bin
./esptool.py --port /dev/cu.SLAB_USBtoUART write_flash 0x3e000 blank.bin
./esptool.py --port /dev/cu.SLAB_USBtoUART write_flash 0x7e000 blank.bin
Please noted that
/dev/cu.SLAB_USBtoUART is the USB port for my USB-TTL interface, yours might be different, run
ls /dev/tty.* to find out your USB port