What is it?

ESP Wireless Terminal is a handy kit allowing Serial communication with remote device over the air.

Assume you have a serial accessible device (like Raspberry Pi or ESP32 node) that falls into boot loop. If for some reason it is not possible or not convenient to bring your laptop to the device proximity, you can attach Wireless Terminal to the device and connect to it via WiFi. Next you use ESP8266 hosted web-based terminal as if you were connected directly

Why did you make it?

Does it ever happened to you that one of your Raspberry Pis falls into boot loop somewhere on the top shelf? Every Pi running from sdcard is doomed to refuse to work one day (unless you run them from read-only filesystem, which you should do BTW).

When that happens I usually disconnect it and bring to the bench to check serial console. Recently It took me more time to actually disassemble device from it's place, than actually fixing it. That get me thinking, surely some people made ESP8266 serial bridge over-the-air, and surely I'd like to have one nearby, next time ping is not coming back.

Not long after first prototype was born, fast forward few month I have revision A board on my bench

Key Features

• Built-in web server hosting Terminal app
• Websockets server for client-server communication
• Ho hard-coded Wi-Fi credentials. User friendly first-time configuration via built-in captive portal
• Onboard OLED 128x64 px screen (Rev B)
• Configure UART speed and bits/parity settings (saved between reboots)

Revision A have onboard battery management IC and works off 14500 Li-Ion battery. It also has RGB led for status indication.

How to use it

Soldering

Kit includes all headers and connectors you need to make it work. However you’d need to have soldering iron and small piece of soldering wire.

Soldering job will take 5 to 30 minutes depending on your skills.

Please check on the project page for details assembly instructions

Revision A is pre-assembled at factory and do not require any soldering.

Firmware

Kits ships with sample Platformio project, so please follow the official Platformio installation guide first.

• Build solution in Platformio
• Upload filesystem image using Upload Filesystem Image task
• Upload firmware using Upload task
• (First time) Upon power on ESP-XXXXXX network will appear, connect to it using your phone and you will be redirected to wifi configuration page
• When configured device restarts and from this moment on it will connect to known network autmatically. Your phone will switch back out of ESP-XXXXXX network
• Go to ESP-XXXXXX page to configure UART settings and enter terminal. Alternatively you can check what IP address device has on the screen or using router logs
• (Alternatively) Please use TCP terminal via telnet on 23 default port: telnet 192.168.4.1
• Connect target device on GPIO15/13 (TX/RX) and you should be able to sent and receive using both described methods

The emulator is implemented using the jQuery Terminal Emulator

Pinouts

UART0 is used for both programming and connection to target. After device start UART0 is reconfigured to use GPIO13/15 for communication, so default GPIO01/03 that normally connected to programmer via UART-USB bridge is not interfering with target device.

UART1 is used for debug output, since RX is not available only TX is present on pin GPIO02, normally it is not connected to anything, so you need to attach external USB-UART bridge.

Open Source

You can find documentation such as board schematics, firmware, and software samples in our GitHub repository. You can also follow progress on our Hackaday.io page.