Hel-Txt - Standalone Meshtastic communicator (Heltec ESP32 V3/V2)

***UPDATE 9/6/24*** 

• Added a proper cover designed to be used with the Silicone cover for the Cardkb.

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This is a case to build a stand alone Meshtastic communicator using the Heltec ESP32 V3 and the M5Stack CardKb. The aim for this project was to make it as compact and simple to print as possible but still being functional and sturdy. I also ensured the ability to add extra features like power switches, GPS, buzzer ,etc.

For those who want to just buy one ready to go here's my stores. Link bellow. 

<<Etsy Shop Here>>
<<Tindie Shop Here>>

List of Materials:
 

• Heltec ESP32 V3 - https://a.co/d/5d0xl5p 
• M5Stack CardKB - https://www.digikey.com/short/v8wjcvb3
• Silicone Cover - https://www.tindie.com/products/36007/ 
• 2000mAh Li-Ion battery - https://store.rokland.com/products/3-7v-1100mah-lithium-rechargeable-battery-1s-1c-lipo-battery-with-protection-board-with-micro-jst-1-25-plug
• 4000mAh Li-Ion battery - 12x50x54mm - https://a.co/d/aBu97UO
• 16mm m3 Hex Socket Head Cap screw  - https://a.co/d/aFIBnWE

Optional:

• GT-U7 GPS Module - https://a.co/d/iN4Jurx
• 2N7000 MOSFET for GPS - https://a.co/d/dzGOds3
• Power Switch - https://a.co/d/4niMcLk
• Passive Buzzer - https://www.aliexpress.us/item/3256806074013807.html?channel=twinner
• BME680 - https://a.co/d/hAfowoO

Printing instructions:
I designed all parts so that they do not need supports. They are on the position that will get you the best possible print.

CardKB Instructions:

1. Make sure to remove the Groove port connector that comes built in to the CardKB, this is necessary to be able to cover the chip and cables that are on the board to prevent shorts.
2. Solder all cables as shown on picture below.
3. Go to Radio Configuration>Module Configurations> Canned Messages and enable Canned messages.
4. Enter “cardkb” with no quotes on field called “Allow input Source”

BME680 Instructions:

1. Solder all cables as shown on picture below.
2. Go to Radio Configuration>Telemtry Configurations> Enable Metric Module

GPS Module Instructions(Optional):

1. Connect GT-U7 with mosfet as shown below
2. Go to Meshtastic app > Radio Configurations > Position
3. Set GPS_RX_PIN to 5 (This will communicate to the TXD slot on the GPS)
4. Set GPS_TX_PIN to 4 (This will communicate to the RXD slot on the GPS)
5. Set PIN_GPS_EN to 3 (This will allow the Meshtastic firmware to turn off the power on the GPS board with the user button of the Heltec Board by pressing it 3 times)

Assembly:
- Assemble all boards and components onto the frame first.
- Place buttons on the Top Display
- Attach the top display and push the 12mm M3 bolts to hold in place.
- Push the nuts onto the bottom cover, they should fit exactly into place.
- Put the bottom cover on the bottom of the frame with the nuts facing down.
- Screw top cover first
- Repeat steps for the keyboard holder piece.

****OPTIONAL SECTIONS*****

Power Switch(Optional):

1. Cut the Black cable from the battery in half.
2. Solder one half to the middle pin of the power switch.
3. Solder the other half to one of the two remaining legs of the power switch.
4. Press power switch into slot designated for the switch.
5. Test.