PeMi Technology - Factory For Materializing Dreams

long range radio messenger

Freedom of communication without borders,
operators, networks, fees !
Your own network, your own rules !
Long range radio communicator


  • PCBWay 3rd PCB Design Contest 2nd place BEST DESIGN !
  • Hackaday Prize Community Vote (Bootstrap Award


Soldering  and assembly video



Articles about project:


Searching sponsors, patrons

Hardware features :

  • Only single chip SAMD21E18
  • QWERTY keyboard - 30 keys (5x6 matrix)
  • LCD on HW SPI:
    -  1.8 TFT LCD display 128x160 ST7735
  • RFM95 long range radio module - 3 freq. by your country
  • Beeper
  • 18650 li-on Battery charging 
  • native HW USB for next features like, modem, sniffer ....

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
  • Battery ... display status only GOOD/LOW
  • Config ... user radio configuration spread factor / power
  • check message delivery confirmation
  • contact list display and check online contacts
  • select recipient or broadcast
  • 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 :)
  • Mass storage bootloader - easy upgrade firmware, just drag&drop

Future software features:

  • Mesh messaging compatible with Meshtastic network...
  • USB Keyboard host 
  • GPS ... 
  • RTC ... 
  • Encryption











Select variant

Coarse stock: sold out

  • GREEN- Armachat 868Mhz - 0pcs
    (with keyboard backlight)

  • BLACK - Armachat 868Mhz -0pcs

  • BLACK - Armachat 915Mhz - 0pcs

  • BLACK - Armachat without radio - 0pcs

Price is for one Armachat unit.

Carefully read please !

Frequency for LoRa long range radio module:

  • 868Mhz is for EU
    You can select in setup 915Mhz for US but you can decrease performance,
    I do not know how much, there is no universal module (I asked in HopeRF)

    On my quick outdoor test I am not see difference.
  • 915Mhz is for USA
  • 433Mhz not available.
  • Check LoRa frequency in your country,

Armachat have no radio device certification, use on your resposibility.

Important notes:

  • Firmware is now very basic

MSD Bootloader:

  • Armachat is now detected as disk drive,
    just copy new firmware as simple uf2 file.

Communication distance:

  • Hard to say ... there is lot variables, antenna, settings, obstacles
    ( Standard RFM95 20dB output, spread factor 12, 2dB antenna )
  • 700m unit on garden desk
  • 1500m unit in window
  • 4300m unit on attic window, but not reliable


  • worldwide flat 11eur with tracking number

  • maybe I send your order in more packages
    (To reduce complete package lost)

  • sending from Slovakia (Heart of Europe) no Custom fees inside EU.

  • Due to the pandemic covid19 is shipping extremely slow

and to some countries impossible (Australia)

Package content:

  • Assembled Armachat unit without 18650 battery
    (version as you can see on top picture)

  • DS3231 and battery holder is not assembed , reserved for future support

  • 868/915 universal antenna

After order:

  • Your payment is protected by PAYPAL

  • There is no automatic order confirmation
    (I write you personal email with tracking number)

  • It can take some time (covid19, holidays ...)

PCB integration

The age of the rectangular PCBs is already far away,

now PCB is not just be a carrier, it is device, enclosure or sensor

Factory for Materializing dreams

One day is it dream, but it's not just a dream, it's just a vision of the near future ...

Finding new solutions

Make simple and reliable circuit

Continuous improvement

Firmware updates

Advanced procedures

SMT assembly

Rapid prototyping