# CircuitMess Chatter 2.0

> DIY encrypted LoRa communicator kit building a pair of devices for off-grid text messaging up to 2km range. Features ESP32, LLCC68 LoRa radio, and 160×128 TFT display.

## Quick Facts

- **Brand:** circuitmess
- **Board Type:** communicator
- **Price:** ~$217
- **Product Readiness:** consumer
- **CPU:** Xtensa LX6 dual-core @ 240MHz, FPU
- **CPU Architecture:** Xtensa LX6
- **CPU Cores:** 2
- **RAM:** 520KB SRAM
- **Flash:** 4MB
- **USB:** USB-C
- **Power:** LiPo battery, USB-C charging
- **Operating Voltage:** 3.3V
- **Antenna:** Built-in PCB antenna
- **Display:** 1.8" TFT 160×128

## Connectivity

- **Wifi:** 802.11 b/g/n
- **Bluetooth:** BLE 4.2
- **Lora:** LLCC68 868MHz

## Open Source

- **Firmware:** Yes
- **Schematics:** No
- **PCB Layout:** No

## Compatible Firmware

arduino, circuitblocks, meshtastic

## Use Cases

- off-grid-communication
- lora-messenger
- stem-education
- emergency-communication
- lora-mesh-networking

## Components

- **ESP32-WROOM-32** (mcu): Espressif ESP32-WROOM-32 module with dual-core Xtensa LX6 at 240MHz, WiFi 802.11 b/g/n, BLE 4.2, 520KB SRAM, and 4MB flash. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2Fesp32-wroom-32_datasheet_en.pdf&ref=openhardware.directory&product=circuitmess-chatter-2-0&source=md-export)
- **LLCC68** (radio): Semtech LLCC68 LoRa transceiver operating at 868MHz for long-range encrypted messaging up to 2km. Supports LoRa and FSK modulation. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.semtech.com%2Fproducts%2Fwireless-rf%2Flora-connect%2Fllcc68&ref=openhardware.directory&product=circuitmess-chatter-2-0&source=md-export)
- **ST7735S** (display-driver): Sitronix ST7735S TFT LCD controller driving a 160×128 pixel color display over SPI. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.displayfuture.com%2FDisplay%2Fdatasheet%2Fcontroller%2FST7735.pdf&ref=openhardware.directory&product=circuitmess-chatter-2-0&source=md-export)
- **74HC165** (io-expander): Two daisy-chained 74HC165 parallel-in/serial-out shift registers reading the 16-button keypad via 3 GPIO pins (DATA, CLOCK, LOAD). — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.ti.com%2Flit%2Fds%2Fsymlink%2Fsn74hc165.pdf&ref=openhardware.directory&product=circuitmess-chatter-2-0&source=md-export)

## Protocols

- **SPI (LoRa)** (HSPI): SCK: GPIO16, MISO: GPIO17, MOSI: GPIO5, CS: GPIO14
- **Shift Register**: DATA: GPIO23, CLOCK: GPIO22, LOAD: GPIO21

## GPIO Map

| Pin | Name | Type | Functions |
|-----|------|------|-----------|
| GPIO16 | LoRa SCK | SPI | digital-output |
| GPIO17 | LoRa MISO | SPI | digital-input |
| GPIO5 | LoRa MOSI | SPI | digital-output |
| GPIO14 | LoRa CS | — | digital-output |
| GPIO4 | LoRa BUSY | — | digital-input |
| GPIO18 | LoRa DIO1 | — | digital-input |
| GPIO23 | Keypad Data | — | digital-input |
| GPIO22 | Keypad Clock | — | digital-output |
| GPIO21 | Keypad Load | — | digital-output |
| GPIO32 | Backlight | — | digital-output, pwm |
| GPIO19 | Buzzer | — | digital-output, pwm |
| GPIO34 | Battery ADC | — | input-only, adc |
| GPIO36 | Wake Button | — | input-only |

## Description

## Overview

The CircuitMess Chatter 2.0 is a DIY electronics kit that builds a pair of encrypted wireless communicators. Using LoRa (Long Range) radio technology via the LLCC68 transceiver, the two devices can exchange encrypted text messages at distances up to 2 kilometers without any WiFi or cellular network — completely off-grid.

Each communicator features an ESP32 microcontroller, a 160×128 color TFT display, a 16-key keypad input via 74HC165 shift registers, a piezo buzzer for notifications, and a USB-C port for charging and programming. Assembly takes approximately 2 hours with detailed step-by-step instructions.

The Chatter 2.0 is fully programmable through CircuitBlocks visual coding or Arduino IDE. The community has also ported Meshtastic firmware to the Chatter 2.0, enabling mesh networking and integration with the broader Meshtastic ecosystem for extended range communication.

## Where to Buy

- [CircuitMess](https://openhardware.directory/r?to=https%3A%2F%2Fcircuitmess.com%2Fproducts%2Fchatter-2-0&ref=openhardware.directory&product=circuitmess-chatter-2-0&source=md-export) — €199.00

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Fcircuitmess.com%2Fproducts%2Fchatter-2-0&ref=openhardware.directory&product=circuitmess-chatter-2-0&source=md-export)
- [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FCircuitMess%2FChatter2-Firmware&ref=openhardware.directory&product=circuitmess-chatter-2-0&source=md-export)
- [wiki](https://openhardware.directory/r?to=https%3A%2F%2Fmeshtastic.org%2Fdocs%2Fhardware%2Fdevices%2Fcommunity-supported%2Fchatter%2F&ref=openhardware.directory&product=circuitmess-chatter-2-0&source=md-export)

## Tags

`circuitmess`, `lora`, `communicator`, `esp32`, `diy-kit`, `stem`, `encrypted`

## Images

![CircuitMess Chatter 2.0](https://nbg1.your-objectstorage.com/openhardware-directory/entities/circuitmess-chatter-2-0/274a9ebcbf96.webp)
![CircuitMess Chatter 2.0](https://nbg1.your-objectstorage.com/openhardware-directory/entities/circuitmess-chatter-2-0/6b1102853c39.webp)

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