# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Project Overview

This is an embedded C application for the LPC54114 microcontroller (ARM Cortex-M4) running on the LPCXpresso54114 development board. The project appears to be a transmitter device (TX) with signal generation, display, USB communication, and power management capabilities.

**Hardware Target:** NXP LPC54114 dual-core Cortex-M4/M0+ microcontroller
**Software Version:** 1.10A (defined in source/System/system.h:18)

## Build System

### Build Commands
```bash
# Build debug version
cd Debug
make all

# Build release version  
cd Release
make all

# Clean build artifacts
make clean
```

### Build Artifacts
- **Target executable:** `TX_App.axf` (ARM executable format)
- **Binary output:** `TX_App.bin` (generated post-build)
- **Memory map:** `TX_App.map`
- **Linker scripts:** `TX_App_Debug.ld`, `TX_App_Release.ld`

### Toolchain
- **Compiler:** arm-none-eabi-gcc
- **Target:** Cortex-M4 with hardware floating point (fpv4-sp-d16)
- **IDE Support:** MCUXpresso, IAR, Keil MDK

## Code Architecture

### Core System Structure

**Main Application Flow:**
- Entry point: `source/main.c`
- System initialization: `source/System/system.c`
- Hardware initialization: `source/init.c`

**Key Subsystems:**

1. **Signal Generation (`source/dds.c`, `source/fgen.c`)**
   - DDS (Direct Digital Synthesis) for frequency generation
   - Function generator capabilities
   - Frequency range: 3.14kHz - 200kHz for broadcast mode
   - System clock: 12MHz

2. **Display System (`source/display.c`, `source/lcd.c`)**
   - Graphics library in `source/Graphics/`
   - Font rendering system in `source/Fonts/`
   - Multi-language support with translations
   - Icon and bitmap handling

3. **Power Management (`source/battery.c`, `source/ports.c`)**
   - Battery type detection (Lithium/Alkaline/External DC)
   - Power limits: 10W (Lithium/Ext), 5W (Alkaline)
   - Clamp control and regulation

4. **Communication (`source/USB/`, `source/broadcast.c`)**
   - USB CDC (Virtual COM) interface
   - Broadcast transmission capabilities
   - Flash update support via USB

5. **Hardware Drivers (`source/driver.c`, `source/io.c`)**
   - SPI communication for external components
   - ADC for measurements
   - Timer and PWM control
   - GPIO port management

### Directory Structure

- `source/` - Main application code
- `source/System/` - System-level configuration and data structures
- `source/USB/` - USB device implementation
- `source/Graphics/` - Display graphics and UI
- `source/Fonts/` - Font data and localization
- `source/Loader/` - Bootloader and flash update functionality
- `drivers/` - NXP SDK peripheral drivers
- `CMSIS/` - ARM CMSIS headers
- `usb/` - USB middleware stack
- `Debug/`, `Release/` - Build output directories

### Key Data Structures

**ClampData_t** (`source/System/system.h:35`): Core control structure containing:
- Slope, voltage, current, impedance measurements
- Power regulation parameters
- Digital potentiometer settings

### Development Notes

- The project uses NXP's MCUXpresso SDK for peripheral drivers
- Hardware-specific fixes are isolated in `source/hwFixes.c`
- Comprehensive change log maintained in `source/AppChangeLog.txt`
- Flash memory layout: Application starts at 0x10000 (64KB offset for bootloader)
- Maximum application size: 192KB

### Testing

Connect via USB (J7 connector) at 115200 baud for debug console output. The application supports firmware updates through the bootloader system.