Source File Map

Complete reference for all source files in the NanoVNA-H firmware.

Core Application Files

File	Lines	Purpose
`main.c`	~3100	Entry point, sweep loop, shell commands, calibration
`nanovna.h`	~1450	Central header with all defines, structs, feature flags
`common.c`	~200	String parsing, utility functions

main.c Components

The main source file contains:

Shell command implementations (40+ commands)
Sweep thread and measurement loop
Calibration routines (SOLT, enhanced response)
Frequency and bandwidth management
USB CDC command processing

Display and UI

File	Lines	Purpose
`ui.c`	~2800	Touch UI, menu system, keyboard input
`plot.c`	~1400	Trace rendering, grid, markers, cell-based redraw
`lcd.c`	~800	LCD driver, SPI communication, SD card interface

UI System

ui.c implements:

Hierarchical menu tree (menu_top, menu_display, menu_marker, etc.)
Touch event processing and calibration
On-screen keyboard for numeric/text input
Lever (rotary encoder) handling

plot.c implements:

Cell-based dirty-region rendering (64x32 pixel cells)
30 trace type calculations and display
Smith chart and polar plot rendering
Marker display and search functions

Signal Processing

File	Lines	Purpose
`dsp.c`	~300	DSP processing, CM4 instructions (F303)
`vna_math.c`	~400	Math tables, FFT, trigonometric functions
`vna_math.h`	~100	Math function declarations

DSP Pipeline

Audio Samples (I2S) → DFT/FFT → Gamma Calculation → Calibration → Display

dsp.c contains:

Sin/cos lookup tables for DFT
Sample accumulation and averaging
Cortex-M4 DSP instruction wrappers (F303 only)

vna_math.c contains:

512-entry sin/cos table (when __VNA_USE_MATH_TABLES__ enabled)
FFT implementation for time domain
Fast math approximations (__USE_VNA_MATH__)

Hardware Drivers

File	Lines	Purpose
`si5351.c`	~600	Si5351/MS5351 frequency synthesizer driver
`tlv320aic3204.c`	~300	TLV320AIC3204 audio codec driver
`hardware.c`	~400	ADC, I2C, RTC, flash, GPIO abstraction
`hardware.h`	~330	Hardware interface declarations

si5351.c Functions

Function	Purpose
`si5351_init()`	Initialize synthesizer, detect variant
`si5351_set_frequency()`	Set output frequency with PLL calculation
`si5351_set_power()`	Set output drive strength
`si5351_reset_pll()`	Reset PLL for frequency changes

tlv320aic3204.c Functions

Function	Purpose
`tlv320aic3204_init()`	Initialize codec, configure I2S
`tlv320aic3204_select()`	Switch between CH0/CH1 measurement
`tlv320aic3204_set_gain()`	Set analog gain for signal level

Data Storage

File	Lines	Purpose
`data_storage.c`	~200	Flash read/write for calibration and config
`flash.c`	~150	Low-level flash erase and program

Storage Functions

Function	Purpose
`caldata_save()`	Save calibration to flash slot
`caldata_recall()`	Load calibration from flash slot
`config_save()`	Save device configuration
`config_recall()`	Load device configuration
`clear_all_config_prop_data()`	Factory reset

USB Interface

File	Lines	Purpose
`usbcfg.c`	~250	USB CDC configuration and descriptors

Implements USB CDC (Communications Device Class) for virtual COM port.

Fonts

File	Size	Description
`fonts/Font5x7.c`	2 KB	Small font for status text
`fonts/Font6x10.c`	3 KB	Normal font (F072 default)
`fonts/Font7x11b.c`	4 KB	Bold font (F303 default)
`fonts/Font11x14.c`	8 KB	Large font for headers
`fonts/numfont16x22.c`	6 KB	Numeric keypad glyphs

FatFS Library

File	Purpose
`FatFs/ff.c`	FAT filesystem implementation
`FatFs/ffunicode.c`	Unicode support for filenames
`FatFs/ff.h`	FatFS API declarations
`FatFs/ffconf.h`	FatFS configuration
`FatFs/diskio.h`	Disk I/O interface

File	Purpose
`NANOVNA_STM32_F072/board.h`	GPIO pin definitions
`NANOVNA_STM32_F072/board.c`	Board initialization
`NANOVNA_STM32_F072/board.mk`	Build configuration
`NANOVNA_STM32_F072/STM32F072xB.ld`	Linker script
`NANOVNA_STM32_F072/halconf.h`	HAL configuration
`NANOVNA_STM32_F072/mcuconf.h`	MCU peripheral configuration
`NANOVNA_STM32_F072/chconf.h`	ChibiOS configuration

File	Purpose
`NANOVNA_STM32_F303/board.h`	GPIO pin definitions
`NANOVNA_STM32_F303/board.c`	Board initialization
`NANOVNA_STM32_F303/board.mk`	Build configuration
`NANOVNA_STM32_F303/STM32F303xC.ld`	Linker script
`NANOVNA_STM32_F303/halconf.h`	HAL configuration
`NANOVNA_STM32_F303/mcuconf.h`	MCU peripheral configuration
`NANOVNA_STM32_F303/chconf.h`	ChibiOS configuration

ChibiOS RTOS

The ChibiOS directory contains the real-time operating system. Key components used:

Component	Purpose
`os/rt/`	Real-time kernel
`os/hal/`	Hardware abstraction layer
`os/hal/ports/STM32/`	STM32-specific HAL
`os/common/startup/`	Startup code
`os/hal/lib/streams/`	Stream I/O (used for shell)

Build Files

File	Purpose
`Makefile`	Main build configuration
`NanoVNA_DAP.cfg`	OpenOCD debug configuration

File Dependencies

main.c
├── nanovna.h (central header)
│   ├── hardware.h
│   └── vna_math.h
├── ch.h (ChibiOS kernel)
└── hal.h (ChibiOS HAL)

ui.c
├── nanovna.h
└── menu definitions

plot.c
├── nanovna.h
└── trace_info_list[], marker_info_list[]

lcd.c
├── nanovna.h
└── FatFs/ff.h (if SD card enabled)

Code Size Reference

Approximate compiled sizes (F072 target, -O2 LTO):

Component	Size
main.c	~25 KB
ui.c	~18 KB
plot.c	~12 KB
lcd.c	~8 KB
si5351.c	~4 KB
vna_math.c	~6 KB
Fonts	~20 KB
ChibiOS	~15 KB
Total	~110 KB

The F072 has 128 KB flash, leaving ~18 KB for calibration and configuration storage.