Designing a Lower-Tech Phone

Phone ingredients #

Screen Options #

• Large Sharp display, $45 https://www.adafruit.com/product/4694

• Smaller Sharp display, $25 https://www.adafruit.com/product/3502

• OLED display, $3 ea (by 5 at a time) https://www.amazon.com/Hosyond-Display-Self-Luminous-Compatible-Raspberry/dp/B09T6SJBV5

(note: for meshtastic RAK modules, proper SSD1306 pinout is: ssd1306 -- VCC GND SCL SDA)

Cellular Modem options #

(Generally looking at the SIM7600 modules)

• Text + voice, $75 https://www.digikey.com/en/products/detail/dfrobot/TEL0162/23028625

• Text-only, $72 (smaller form factor) https://www.amazon.com/SIM7600G-H-4G-Communication-Module-Positioning-Standard/dp/B0BTP93H8H

Keyboard #

• CardKB, $8 https://www.digikey.com/en/products/detail/m5stack-technology-co-ltd/U035-B/16679766

Battery #

[TBD -- need to figure out whether 'boost' approach works]

Microcontroller #

• Itsy Bitsy M4, $15 https://www.adafruit.com/product/3800

• Itsy Bitys nRF52840, $20 https://www.adafruit.com/product/4481

Sat 08 Mar 2025 08:39:40 PM EST

phone repo #

This is where the phone code lives https://gitlab.com/edgecollective/neighborhood-mesh

Wed 19 Feb 2025 08:14:21 PM EST

Testing power req's ....

Page for audio + text module is here

And wiki here

Initial run -- text-only #

• Module -- sim7600 text module for $73 on Amazon
• Small Screen -- ssd1306 oled for $8 on Amazon
• SIM card -- $45 Mint Mobile $15/month plan on Amazon
• Microcontroller -- nrf express itsy bitsy for $20 on Digikey
• Keyboard -- m5 keyboard for $8 on Digikey
• Large Screen -- adafruit sharp display for $44 on Digikey
• Boost (already purchased)
• Antenna (already purchased)
• PCB (to design)
• Case (to design)

What are the specs on the BAT pin?