Features:

• Lower Key Height / More Ergonomic Keyboard 

• Raised outer ridge to prevent accidental keypresses

• Recessed power switch

• Alert buzzer

• Textured Grips / Edges 

• Sunshade for Screen - Also provides protection and prevents accidental keypresses while face down   

• Recessed antenna mount to reduce overall size and protect antenna 

• Brass inserts for screws allowing easier reassembly 

• Attachment loop to hook device to backpack, tree, bike, etc while out exploring 

• To-Do: Optional replacement backplate including a kickstand when stationary. 

  • Personally opted to use a folding antenna. Lay device flat, fold antenna up!

Parts Selection for Building: 

The links below are sponsored promotions through the Amazon Affiliate program. Purchasing parts through these links ensures part compatibility and greatly helps me to fund further products!  

Depending on what you want to build, you may have to pick and choose parts! You may choose to use different parts from different vendors, which will likely be cheaper if you do not need large quantities of screws and such!  

Build Notes 

• The case is designed to fit a Heltec V3 WITHOUT pins! You will need to solder all connections! 

• The case is designed to fit a CardKB without pin header! You will need to remove the plug and solder directly to the CardKB.  

Electronics 

• Heltec V3 LoRa - https://amzn.to/4cIXtGz  

• CardKB - https://shop.m5stack.com/products/cardkb-mini-keyboard-programmable-unit-v1-1-mega8a  

• GT-U7 GPS Module with Ceramic Antenna - https://amzn.to/4rAQO54  

• 2n7000 MOSFET (optional, battery save for GPS) - https://amzn.to/3NiFa0E  

• 3000mah 105050 Battery (10x50x50mm) - https://amzn.to/41Hxt7E  

• Mini Buzzer (9x5.5mm) - https://amzn.to/4sR5T3X  

• SPDT Switch (11x6x12mm) - https://amzn.to/4sQVG7f 

• Whip Antenna (optional) - https://amzn.to/4tozQrT  

• Folding Anteanna (optional) - https://amzn.to/4crx3al

Hardware 

• M3 Button Head Screws (8mm) – https://amzn.to/3P8Seq0  

• Heat Set Threaded Brass Inserts (M3xD5-L4) - https://amzn.to/4lCJ55a  

Wiring and Pinout 

GPS  

GPS VCC → Heltec 3.3v   GPS TX  → Heltec GPIO 48   GPS RX  → Heltec GPIO 47   GPS GND → MOSFET DRAIN   MOSFET SOURCE → Heltec GND   MOSFET GATE   → Heltec GPIO 26  

Buzzer  

Buzzer Positive → Heltec GPIO 7   Buzzer Negative → Heltec GND  

CardKB  

CardKB GND  Pin 1 → Heltec GND   CardKB 3.3v Pin 2 → Heltec 3.3V   CardKB SDA  Pin 3 → Heltec GPIO 41   CardKB SCL  Pin 4 → Heltec GPIO 42 

Battery 

Battery Positive → Heltec Positive Battery Terminal (JST-GH 1.25mm)   Battery Negative → Switch → Heltec Negative Battery Terminal (JST-GH 1.25mm) 

GPIO pins are tested to work with my device configuration. You may use alternate pins if needed. 

Software Configuration – Configure via App 

Device Config 

Buzzer GPIO → Pin 7 

Position Config 

Device GPS        → Enabled  GPS Receive  GPIO → Pin 48  GPS Transmit GPIO → Pin 47  GPS Enable   GPIO → Pin 26 

Canned Messages Config 

Options → Enabled  Presets → M5 Stack CardKB 

External Notification Config 

Enabled       → True  Alert Bell    → True  Alert Message → True  PWM Buzzer    → True  Active        → True  Output GPIO   → Pin 7 

Thanks for downloading! 

If you have any issues, please contact Pilotgeek45@gmail.com . I greatly appreciate any feedback; each build helps contribute to further improvements.