Debug and System Commands

Commands for system information, debugging, and remote desktop control.

info

Display device information.

Syntax

info

Output

ch> info
Board: NanoVNA-H
2019-2025 Copyright NanoVNA.com
based on  @DiSlord @edy555 ... source
Licensed under GPL.
Version: 1.2.44 [p:101, IF:12k, ADC:192k, Lcd:320x240]
Build Time: Jan 29 2026 - 14:30:45
Architecture: ARMv6-M Core Variant: Cortex-M0
Platform: STM32F072xB

Information Fields

Field	Description
Board	Hardware variant
Version	Firmware version with build parameters
p:	Maximum sweep points
IF:	IF frequency in kHz
ADC:	ADC sample rate in kHz
Lcd:	Display resolution
Architecture	CPU architecture
Platform	MCU part number

version

Display firmware version.

Syntax

version

Output

ch> version
1.2.44

Notes

Shorter output than info, useful for scripts checking version.

help

List available commands.

Syntax

help

Output

ch> help
Commands: scan scan_bin data frequencies freq sweep power bandwidth
time sd_list sd_read sd_delete saveconfig clearconfig dump
touchcal touchtest pause resume cal save recall trace marker
edelay s21offset capture measure refresh touch release vbat
tcxo reset smooth config usart_cfg usart vbat_offset transform
threshold help info version color

reset

Reset the device.

Syntax

reset [dfu]

Parameters

Parameter	Description
(none)	Normal reset
`dfu`	Reset into DFU bootloader

Examples

ch> reset
(device resets)

ch> reset dfu
(device enters DFU bootloader)

DFU Mode

After reset dfu:

Device appears as DFU device (VID:PID 0483:DF11)
Flash new firmware using dfu-util
Reset device to exit DFU mode

dfu-util -d 0483:df11 -a 0 -s 0x08000000:leave -D firmware.bin

Remote Desktop Commands

These commands enable remote control and screen viewing.

refresh

Get current screen data.

Syntax

refresh

Output

Binary LCD buffer data in RGB565 format.

Usage

Used by remote desktop applications to display the NanoVNA screen.

touch

Simulate touch press.

Syntax

touch <x> <y>

Parameters

Parameter	Description
`x`	X coordinate (0-319 or 0-479)
`y`	Y coordinate (0-239 or 0-319)

Example

ch> touch 200 120

release

Simulate touch release.

Syntax

release

Example

ch> touch 200 120
ch> release

Remote Desktop Sequence

refresh - Get screen image
touch x y - Send touch event
release - Release touch
refresh - Get updated screen

Debug Commands

These commands are typically disabled in release builds. Enable by uncommenting defines in main.c.

threads

Display ChibiOS RTOS thread information (requires ENABLE_THREADS_COMMAND, and CH_CFG_USE_REGISTRY in chconf.h).

Syntax

threads

Output

ch> threads
stklimit|   stack|stk free|    addr|refs|prio|    state|        name
20000200  200003F0      448  200003F8   1  128    READY       sweep
20000600  200007F0      320  200007F8   1   64    SLEEP        main

Column Descriptions

Column	Description
`stklimit`	Stack lower bound address
`stack`	Stack pointer (current position)
`stk free`	Bytes of stack remaining (watch for low values)
`addr`	Thread control block address
`refs`	Reference count
`prio`	Thread priority (higher = more urgent)
`state`	ChibiOS thread state (READY, SLEEP, SUSPENDED, etc.)
`name`	Thread name string

stat

Display system statistics (requires ENABLE_STAT_COMMAND).

Syntax

stat

Output

Shows timing and performance statistics.

gain

Get/set codec gain (requires ENABLE_GAIN_COMMAND).

Syntax

gain [value]

Notes

Used for debugging audio codec signal levels.

si

Write to Si5351 registers directly (requires ENABLE_SI5351_REG_WRITE).

Syntax

si <register> <data>

Parameters

Parameter	Description
`register`	Si5351 register address (0–255)
`data`	Byte value to write (0–255, supports hex `0x` prefix)

Examples

ch> si 16 0x4F
ch> si 3 0xFF

i2c

Write to TLV320AIC3204 audio codec registers via I2C (requires ENABLE_I2C_COMMAND).

Syntax

i2c <page> <register> <data>

Parameters

Parameter	Description
`page`	Codec register page (0–255)
`register`	Register address within the page
`data`	Byte value to write

Examples

ch> i2c 0 81 0xC0
ch> i2c 1 1 0x08

Notes

The TLV320AIC3204 uses a paged register space — you must specify the page
Calls tlv320aic3204_write_reg(page, reg, data) internally
Useful for adjusting codec gain, input routing, and sample rates during development

lcd

Send commands to the LCD controller (requires ENABLE_LCD_COMMAND).

Syntax

lcd <cmd> [data...]

Parameters

Parameter	Description
`cmd`	LCD command byte
`data...`	Optional data bytes (variable number)

Examples

ch> lcd 0x04
ret = 0x00858552

ch> lcd 0x28
ret = 0x00000000

Notes

Sends a register read/write via lcd_send_register()
Returns the controller response as a 32-bit hex value
The command byte and behavior depends on the display controller (ILI9341, ST7789, or ST7796S)
Useful for reading device ID registers or debugging display initialization

band (b)

Configure Si5351 frequency band parameters (requires ENABLE_BAND_COMMAND).

Syntax

b <band_index> <parameter> <value>

Parameters

Parameter	Description
`band_index`	Band configuration index
`parameter`	One of the subcommands below
`value`	Numeric value to set

Band Parameter Subcommands

Subcommand	Description
`mode`	Output mode for this band
`freq`	Frequency boundary
`div`	PLL divider
`mul`	PLL multiplier
`omul`	Output multiplier
`pow`	Output power level
`opow`	Opposite port power level
`l`	Left channel configuration
`r`	Right channel configuration
`lr`	Both channels
`adj`	Frequency adjustment

Examples

ch> b 0 mode 1
ch> b 2 freq 300000000
ch> b 1 pow 3

Notes

Calls si5351_update_band_config() with the parsed index, parameter, and value
Used for characterizing synthesizer behavior at different frequency ranges
Incorrect settings can degrade measurement accuracy

test

Run diagnostic tests (requires ENABLE_TEST_COMMAND).

Syntax

test

Notes

Runs internal hardware tests.

dac

Set the DAC output value (requires __VNA_ENABLE_DAC__).

Syntax

dac <value>

Parameters

Parameter	Description	Range
`value`	DAC output value	0–4095 (12-bit)

Examples

ch> dac
usage: dac {value(0-4095)}
current: 2048

ch> dac 1024

Notes

Sets channel 2 of the on-chip DAC via dac_setvalue_ch2()
With no arguments, displays usage and the current DAC value
Value is masked to 12 bits (& 0xFFF)
Used for calibrating analog circuits or testing signal levels

port

Select the audio codec input port (requires ENABLE_PORT_COMMAND).

Syntax

port <channel>

Parameters

Value	Description
`0`	TX port (measurement/stimulus channel)
`1`	RX port (reference channel)

Example

ch> port 0
ch> port 1

Notes

Calls tlv320aic3204_select() to switch the codec input multiplexer
Used for debugging signal path routing between the TX and RX channels

t (Si5351 timings)

Configure Si5351 timing parameters (requires ENABLE_SI5351_TIMINGS).

Syntax

t <index> <value>

Parameters

Parameter	Description
`index`	Timing parameter index
`value`	Timing value

Example

ch> t 0 100
ch> t 1 50

Notes

Calls si5351_set_timing() to adjust PLL settling and output timing
Used for optimizing sweep speed vs. measurement stability
Incorrect values can cause PLL lock failures or measurement glitches

i (I2C timings)

Configure I2C bus timing parameters (requires ENABLE_I2C_TIMINGS).

Syntax

i <scldel> <sdadel> <sclh> <scll>

Parameters

Parameter	Description
`scldel`	SCL delay (setup time)
`sdadel`	SDA delay (hold time)
`sclh`	SCL high period
`scll`	SCL low period

Example

ch> i 4 2 15 15

Notes

Directly configures the STM32 I2C TIMINGR register fields
Used for tuning I2C bus speed when experimenting with different clock rates
All four parameters are required
Applies immediately via set_I2C_timings()

Enabling Debug Commands

To enable debug commands, edit main.c and uncomment the relevant defines:

// Enable for debug builds
#define ENABLE_THREADS_COMMAND     // threads
#define ENABLE_STAT_COMMAND        // stat
#define ENABLE_GAIN_COMMAND        // gain
#define ENABLE_TEST_COMMAND        // test
#define ENABLE_I2C_COMMAND         // i2c (codec register access)
#define ENABLE_LCD_COMMAND         // lcd (display controller access)
#define ENABLE_SI5351_REG_WRITE    // si (synth register write)
#define ENABLE_BAND_COMMAND        // b (band configuration)
#define ENABLE_PORT_COMMAND        // port (codec input select)
#define ENABLE_SI5351_TIMINGS      // t (synth timing)
#define ENABLE_I2C_TIMINGS         // i (I2C bus timing)
#define ENABLE_SAMPLE_COMMAND      // sample, gamma
#define __VNA_ENABLE_DAC__         // dac

Then rebuild the firmware.

System Information

Memory Usage

Check stack usage:

// In threads output, stack column shows used stack
// Compare to allocated: waThread1 = 1024 bytes

Performance

Time domain profiling (if enabled):

START_PROFILE;
// code to measure
STOP_PROFILE;

Source Code Reference

All debug commands in main.c:

Command	Handler	Line	Compile Flag
`info`	`cmd_info`	2630	`ENABLE_INFO_COMMAND`
`version`	`cmd_version`	2561	(always)
`help`	`cmd_help`	3035	(always)
`reset`	`cmd_reset`	517	(always)
`refresh`	`cmd_refresh`	2774	`__REMOTE_DESKTOP__`
`touch`	`cmd_touch`	2785	`__REMOTE_DESKTOP__`
`release`	`cmd_release`	2791	`__REMOTE_DESKTOP__`
`threads`	`cmd_threads`	2706	`ENABLE_THREADS_COMMAND`
`stat`	`cmd_stat`	2499	`ENABLE_STAT_COMMAND`
`gain`	`cmd_gain`	1262	`ENABLE_GAIN_COMMAND`
`si`	`cmd_si5351reg`	2597	`ENABLE_SI5351_REG_WRITE`
`i2c`	`cmd_i2c`	2665	`ENABLE_I2C_COMMAND`
`lcd`	`cmd_lcd`	2691	`ENABLE_LCD_COMMAND`
`b`	`cmd_band`	2678	`ENABLE_BAND_COMMAND`
`test`	`cmd_test`	2416	`ENABLE_TEST_COMMAND`
`dac`	`cmd_dac`	690	`__VNA_ENABLE_DAC__`
`port`	`cmd_port`	2475	`ENABLE_PORT_COMMAND`
`t`	`cmd_si5351time`	2587	`ENABLE_SI5351_TIMINGS`
`i`	`cmd_i2ctime`	2619	`ENABLE_I2C_TIMINGS`