Project Details

• https://www.hackster.io/news/off-grid-wireless-communication-with-the-armachat-762b1cc966e5

Experience freedom of communication without 
borders
operators
networks
fees !!!

Create your own network, your own rules !!!

First prototypes manufactured in Aisler :

FUSION model - combine best features from both prototypes Manufactured in PCBWAY:

Hardware features:

• SAMD21G18 for desktop version (pocket version use SAMD21E18, more easy to solder in TQFP32)
• QWERTY keyboard
  - 40 keys (4x10) desktop version
  - 30 keys (5x6) pocket version
• 18650 li-on battery
• 1.8 TFT LCD display 128x160 ST7735
• RFM95 long range radio module
  - 3 freq. by your country
  - IRQ / wake up
• Beeper
• Battery charging
• Software RTC with alarms

Working software features:

• Send message ... compose and send message to specified recipient or broadcast 
• Receive message ... message is received on background and stored in memory.
• Message editor ... write message about +/- 80 characters long ...
  80 is now best readable on full display ....
• Message memory ... all send/received messages are stored in memory
• Display memory ... display memory content
• RTC .... display time
• Battery ... display battery voltage
• Config ... user radio configuration spread factor / power
• time set
• check message delivery confirmation
• contact list display and check online contacts
• select recipient or broadcast
• sort from memory by contact
• BEST working feature - resend undelivered messages
  if delivery fail, message is stored with "undelivered" attribute. Every station at power on broadcast "Ready receive status", then if any near station receive this broadcast and have undelivered message automatically try send this messages,
  if then receive confirmation mark messages in memory as DELIVERED :)

TODO software features:

• add message encryption
• think about message forward (mesh)
• add some USB link features like work as usb modem, send receive/message from PC terminal
• GPS position parse

STEM Learning:

What you can learn on this board?

• modern architecture based on M0 arduino zero compatible, with lot memory and native USB
• QWERTY keyboard matrix reading
• complex input/output HID processing read keyboard data,
• create and display graphics, save data to flash, send results over radio or usb
• radio communication with world best, most advanced long range radio technology
• work with I2C sensors or process GPS data
• learn lot about network architecture, packets, communication, addresing, delivery confirmation
• RTC clock and alarms
• power management, sleep, wake by alarm, wake on receive

( all this things I learning now on this project)

Production and marketing plans:

Hardware is very simple and easy to solder by hand (in pocket version with SAMD21E18), low active component count make it very attractive as learn to solder kit. Unfortunately SAMD21 come without bootloader, this is little problem because SAMD need special tools to burn bootloaders, I have no experience how much is complicated burn bootloader in factory on bare unsoldered chip. I suggesting sell this as semi populated board > PCBA all active components except buttons and radio module (Unsoldered radio module give small advantage because there is 3 world frequencies) Why TH tactile switches? because is very important to precise align with front cover plate and this can be little hard with hand.

SWOT analysis

Strengths:

• no competition with almost finished and working communicator
• compact design
• qwerty keyboard, much user friendly than encoders or arrow keys
• officially supported Arduino powerful microcontroller with lot free memory and computation power
• using only 15% memory now, unlimited future enhancements
• extremely simple just one easy solder chip and buttons, cheap and low component count
• low power consumption
• color graphics display

Weaknesses:

• no community, no users (maybe because I have not started selling )
• currently no mesh networking or advanced message routing
• my programing knowledge is limited (I quickly learning)

Opportunities:

• MOTTO> My network = my rules, no borders, no limits, no operators.
• create own private message network with encryption possibility
• disaster radio

Threats:

• ESP32 based devices can create unlimited communication with WIFI and BLE
  and forward messages between networks
  (I see future use ESP32 as gateways between wifi <>RFM95 for smartphone, not as standalone device
  SAMD consume much less energy)

• device is very easy replicable and anybody can sell cheaper version

Some screenshots: