README.md
# LoRa Chatting Device carrier PCB
Carrier PCB matching the LoraKartX reference firmware, now using the exact JLCPCB ESP32-WROOM-32E-N4 module (`C701341`) directly instead of an ESP32 DevKit socket. The remaining functional interfaces are the RYLR993/998 UART LoRa module, 2.8-inch ILI9341/XPT2046 display, DS3231 RTC, charging/boost power stage, and a 1-cell Li-ion/LiPo battery.
Because the WROOM module has no DevKit onboard regulator, `U2` is the imported JLCPCB AMS1117-3.3 (`C6186`) supplying its 3.3 V rail from the boosted 5 V rail.
## Firmware pin map
| Function | ESP32 GPIO |
|---|---:|
| LoRa RXD / TXD | GPIO13 / GPIO14 |
| RTC SDA / SCL | GPIO25 / GPIO26 |
| SPI MOSI / MISO / SCK | GPIO23 / GPIO19 / GPIO18 |
| TFT CS / DC / RESET | GPIO15 / GPIO2 / GPIO4 |
| Touch CS / IRQ | GPIO21 / GPIO22 |
Set the XL6009 output to **5.0 V before fitting the ESP32**. `SW1` accepts a latching power switch between charger output and boost input. Do not power the ESP32 USB port and boost rail simultaneously unless the DevKit has suitable isolation.
The design is autorouted as a two-layer carrier. Verify the exact mechanical dimensions and pin order of purchased breakout modules before fabrication. Radio band, antenna, battery safety, and regulatory compliance remain the builder's responsibility.
All routed copper uses 0.15 mm thin traces, including power nets, as requested. Exact JLCPCB imports are used for C1 (`C335982`), C2 (`C49678`), BT1 (`C131337`), and SW1 (`C124375`). Socket/header LCSC references are assigned to J1-J5: `C50950`, `C7509524`, `C40877`, `C40877`, and `C2718488`. U1 needs two 1x19 female headers (`C25503123`, quantity 2); this is documented separately because assigning one header to the combined 38-pin DevKit footprint would create an incorrect BOM/footprint association. The complete breakout modules themselves are not stocked as matching JLCPCB components.
Build with `npm install`, then run `tsci check netlist`, `tsci check schematic-placement`, `tsci check placement`, and `tsci build --pcb-png --schematic-png --kicad-project-zip`.
