NetX DHCP and a single-connection HTTP camera server over ESP32-C6. More...

#include <stdint.h>
#include <string.h>
#include "c6_camera_server.h"
#include "nx_api.h"
#include "nx_ether_driver_c6.h"
#include "nxd_dhcp_client.h"
#include "ra8_attributes.h"
#include "ra8_c6link.h"
#include "ra8_err.h"
#include "tx_api.h"

Include dependency graph for c6_cam_net.c:

Enumerations
enum	c6_cam_net_format_t : uint32_t { k_c6_cam_net_decimal_digits = 10U , k_c6_cam_http_get_min = 5U }
	Decimal formatting and minimum HTTP request sizes. More...

Functions
static UINT	internal_c6_cam_net_create (void)
	Create the static NetX packet pool and IP instance.
ra8_err_t	c6_cam_net_up (ra8_c6link_t link, const ra8_c6link_mac_t mac, c6_cam_lease_t *out)
	Bind NetX to an associated raw C6 link and obtain a DHCP lease.
static UINT	internal_c6_cam_http_send (const void *data, uint32_t bytes)
	Send an exact byte span over the accepted HTTP socket.
static uint32_t	internal_c6_cam_append (char out, uint32_t at, uint32_t cap, const char text)
	Append bounded text to a fixed HTTP header buffer.
static uint32_t	internal_c6_cam_append_u32 (char *out, uint32_t at, uint32_t cap, uint32_t value)
	Append an unsigned decimal value to a fixed buffer.
static UINT	internal_c6_cam_http_response (const char type, const void body, uint32_t body_bytes, const c6_cam_frame_timing_t *timing, uint32_t timestamp_ms)
	Send one complete close-delimited HTTP response.
static UINT	internal_c6_cam_http_stream (void)
	Serve a bounded multipart MJPEG sequence.
static bool	internal_c6_cam_request_is (const char request, uint32_t bytes, const char path)
	Match a bounded HTTP GET request path.
static void	internal_c6_cam_http_frame (void)
	Capture and serve one JPEG still response.
static void	internal_c6_cam_http_audio (void)
	Snapshot and serve the current audio window.
static void	internal_c6_cam_http_dispatch (const char *request, uint32_t bytes)
	Dispatch a bounded HTTP request to one route handler.
static void	internal_c6_cam_http_handle (void)
	Receive and dispatch one HTTP request.
void	c6_cam_http_serve (void)
	Serve the browser UI and fresh JPEG frames forever.

Variables
static NX_PACKET_POOL	s_pool
static uint8_t	s_pool_mem [k_c6_cam_net_pool_bytes]
static NX_IP	s_ip
static uint8_t	s_ip_stack [k_c6_cam_net_ip_stack]
static uint8_t	s_arp_cache [k_c6_cam_net_arp_bytes]
static NX_DHCP	s_dhcp
static NX_TCP_SOCKET	s_http_socket
static CHAR	s_pool_name [] = "c6_cam_pool"
static CHAR	s_ip_name [] = "c6_cam_ip"
static CHAR	s_dhcp_name [] = "c6_cam_dhcp"
static CHAR	s_socket_name [] = "c6_cam_http"
static const char	s_page []

Detailed Description

NetX DHCP and a single-connection HTTP camera server over ESP32-C6.

Tag: [Ring 6 / APP] {World: S}

The C6 remains the validated esp-hosted L2 co-processor. NetX Duo, DHCP, TCP, HTTP parsing, camera capture and JPEG generation all run on RA8. The page uses one persistent multipart/MJPEG connection. /frame.jpg remains available for still capture, diagnostics, and HIL qualification.

Copyright: Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Since: 0.1.0

Definition in file c6_cam_net.c.

Enumeration Type Documentation

◆ c6_cam_net_format_t

enum c6_cam_net_format_t : uint32_t

Decimal formatting and minimum HTTP request sizes.

Enumerator
k_c6_cam_net_decimal_digits	Decimal digits in a 32-bit integer.
k_c6_cam_http_get_min	Minimum bytes in an HTTP GET prefix.

Definition at line 221 of file c6_cam_net.c.

Function Documentation

◆ c6_cam_http_serve()

void c6_cam_http_serve ( void )

Serve the browser UI and fresh JPEG frames forever.

Definition at line 550 of file c6_cam_net.c.

References c6_cam_puts(), internal_c6_cam_http_handle(), k_c6_cam_http_port, k_c6_cam_listen_backlog, k_c6_cam_tcp_window, s_http_socket, s_ip, s_socket_name, and tx_thread_sleep.

Referenced by internal_c6_cam_worker_entry().

◆ c6_cam_net_up()

ra8_err_t c6_cam_net_up	(	ra8_c6link_t *	link,
		const ra8_c6link_mac_t *	mac,
		c6_cam_lease_t *	out )

nodiscard

Bind NetX to an associated raw C6 link and obtain a DHCP lease.

Definition at line 107 of file c6_cam_net.c.

References c6_cam_lease_t::bound, c6_cam_lease_t::dhcp_server, c6_cam_lease_t::gateway, internal_c6_cam_net_create(), c6_cam_lease_t::ip, k_c6_cam_dhcp_wait_ms, k_ra8_err_not_initialized, k_ra8_err_null_ptr, k_ra8_err_timeout, k_ra8_ok, c6_cam_lease_t::mask, nx_ether_driver_c6_bind(), nx_ether_driver_c6_set_mac(), ra8_c6link_mac::octet, s_dhcp, s_dhcp_name, and s_ip.

Referenced by internal_c6_cam_join().

◆ internal_c6_cam_append()

uint32_t internal_c6_cam_append	(	char *	out,
		uint32_t	at,
		uint32_t	cap,
		const char *	text )

static

Append bounded text to a fixed HTTP header buffer.

Copies until NUL or capacity and returns the next write position.

Parameters

[out]	out	Destination character buffer.
[in]	at	Initial write offset.
[in]	cap	Destination capacity.
[in]	text	NUL-terminated source text.

Returns: Updated write offset.

Return values

uint32_t First unwritten offset, never greater than cap.

Precondition: out addresses cap writable bytes.; text is nonnull and NUL-terminated.

Postcondition: Source text is unchanged.; Only destination bytes in [at, return) are modified.

Note: Truncation is represented by a return value equal to cap.

Since: 0.1.0

Definition at line 212 of file c6_cam_net.c.

Referenced by internal_c6_cam_http_response(), and internal_c6_cam_http_stream().

◆ internal_c6_cam_append_u32()

uint32_t internal_c6_cam_append_u32	(	char *	out,
		uint32_t	at,
		uint32_t	cap,
		uint32_t	value )

static

Append an unsigned decimal value to a fixed buffer.

Formats digits in reverse stack storage and copies them in display order.

Parameters

[out]	out	Destination character buffer.
[in]	at	Initial write offset.
[in]	cap	Destination capacity.
[in]	value	Value to append.

Returns: Updated write offset.

Return values

uint32_t First unwritten offset, never greater than cap.

Precondition: out addresses cap writable bytes.; at is no greater than cap.

Postcondition: The value's digits are appended until capacity is exhausted.; No destination byte before at is modified.

Note: No NUL terminator is appended.

Since: 0.1.0

Definition at line 243 of file c6_cam_net.c.

References k_c6_cam_net_decimal_digits.

Referenced by internal_c6_cam_http_response(), and internal_c6_cam_http_stream().

◆ internal_c6_cam_http_audio()

void internal_c6_cam_http_audio ( void )

static

Snapshot and serve the current audio window.

Requests a stable WAV snapshot from the ping-pong audio backend and returns either that snapshot or a bounded not-ready response to the client.

Precondition: Audio state and HTTP packet resources are initialized.; The connected socket may accept one complete response attempt.

Postcondition: A WAV or bounded text not-ready response is attempted.; Successful snapshots retain their capture timestamp in the response.

Note: Successful responses include the capture timestamp.

Since: 0.1.0

Definition at line 462 of file c6_cam_net.c.

References c6_cam_audio_snapshot_wav(), c6_cam_put_u32(), c6_cam_puts(), internal_c6_cam_http_response(), k_ra8_ok, and RA8_INTERNAL.

Referenced by internal_c6_cam_http_dispatch().

◆ internal_c6_cam_http_dispatch()

void internal_c6_cam_http_dispatch	(	const char *	request,
		uint32_t	bytes )

static

Dispatch a bounded HTTP request to one route handler.

Matches the request path against the stream, still-frame, audio, and health endpoints, falling back to the embedded browser page.

Parameters

[in]	request	Extracted request prefix.
[in]	bytes	Extracted request-byte count.

Precondition: request addresses at least bytes readable bytes.; Camera, audio, and HTTP response resources are initialized.

Postcondition: At most one response handler is invoked.; Unrecognized routes receive the embedded browser page.

Note: Handler response failures are resolved by the caller's socket teardown.

Since: 0.1.0

Definition at line 498 of file c6_cam_net.c.

References internal_c6_cam_http_audio(), internal_c6_cam_http_frame(), internal_c6_cam_http_response(), internal_c6_cam_http_stream(), internal_c6_cam_request_is(), RA8_INTERNAL, and s_page.

Referenced by internal_c6_cam_http_handle().

◆ internal_c6_cam_http_frame()

void internal_c6_cam_http_frame ( void )

static

Capture and serve one JPEG still response.

Captures through the configured camera backend, emits the JPEG with timing metadata on success, and otherwise sends a bounded diagnostic body.

Precondition: Camera state and HTTP packet resources are initialized.; The connected socket may accept one complete response attempt.

Postcondition: A JPEG or bounded text error response is attempted.; Capture timing or the backend error is reported on the console.

Note: Capture diagnostics are emitted on the console.

Since: 0.1.0

Definition at line 419 of file c6_cam_net.c.

References c6_cam_camera_capture_jpeg(), c6_cam_camera_report_last_error(), c6_cam_put_u32(), c6_cam_puts(), c6_cam_frame_timing_t::capture_ms, c6_cam_frame_timing_t::convert_ms, c6_cam_frame_timing_t::encode_ms, internal_c6_cam_http_response(), k_ra8_ok, ra8_err_to_str(), RA8_INTERNAL, and c6_cam_frame_timing_t::timestamp_ms.

Referenced by internal_c6_cam_http_dispatch().

◆ internal_c6_cam_http_handle()

void internal_c6_cam_http_handle ( void )

static

Receive and dispatch one HTTP request.

Extracts a bounded request prefix and serves stream, frame, audio, health, or UI content.

Precondition: s_http_socket is connected to one client.; Camera, audio, packet pool, and IP state are initialized.

Postcondition: Any received request packet is released exactly once.; At most one route handler is selected for the request.

Note: Response failures are handled by subsequent socket teardown.

Since: 0.1.0

Definition at line 532 of file c6_cam_net.c.

References internal_c6_cam_http_dispatch(), k_c6_cam_request_max, RA8_INTERNAL, and s_http_socket.

Referenced by c6_cam_http_serve().

◆ internal_c6_cam_http_response()

UINT internal_c6_cam_http_response	(	const char *	type,
		const void *	body,
		uint32_t	body_bytes,
		const c6_cam_frame_timing_t *	timing,
		uint32_t	timestamp_ms )

static

Send one complete close-delimited HTTP response.

Builds bounded headers with optional timing and timestamp metadata, then sends the body.

Parameters

[in]	type	NUL-terminated MIME content type.
[in]	body	Readable response body.
[in]	body_bytes	Response body size.
[in]	timing	Optional camera timing metadata.
[in]	timestamp_ms	Optional monotonic media timestamp.

Returns: NetX status code.

Return values

NX_SUCCESS	Header and body were sent.
NX_NOT_SUCCESSFUL	A socket send failed.

Precondition: type is NUL-terminated and body spans body_bytes bytes.; The HTTP socket is connected.

Postcondition: The body is sent only after a successful header send.; Caller-owned response data remains unchanged.

Note: A zero timestamp suppresses the timestamp header.

Since: 0.1.0

Definition at line 275 of file c6_cam_net.c.

References c6_cam_frame_timing_t::capture_ms, c6_cam_frame_timing_t::convert_ms, c6_cam_frame_timing_t::encode_ms, internal_c6_cam_append(), internal_c6_cam_append_u32(), internal_c6_cam_http_send(), and RA8_INTERNAL.

Referenced by internal_c6_cam_http_audio(), internal_c6_cam_http_dispatch(), and internal_c6_cam_http_frame().

◆ internal_c6_cam_http_send()

UINT internal_c6_cam_http_send	(	const void *	data,
		uint32_t	bytes )

static

Send an exact byte span over the accepted HTTP socket.

Chunks caller data into bounded NetX packets and sends them in order.

Parameters

[in]	data	Readable body or header bytes.
[in]	bytes	Total bytes to transmit.

Returns: NetX status code.

Return values

NX_SUCCESS	The entire span was queued.
NX_NOT_SUCCESSFUL	Packet allocation, append, or socket send failed.

Precondition: data addresses at least bytes readable bytes.; s_http_socket is connected and s_pool is initialized.

Postcondition: On success, exactly bytes were sent in order.; Failed unsent packets are released before return.

Note: Exact non-success codes are propagated from NetX.

Since: 0.1.0

Definition at line 163 of file c6_cam_net.c.

References k_c6_cam_http_chunk, RA8_INTERNAL, s_http_socket, and s_pool.

Referenced by internal_c6_cam_http_response(), and internal_c6_cam_http_stream().

◆ internal_c6_cam_http_stream()

UINT internal_c6_cam_http_stream ( void )

static

Serve a bounded multipart MJPEG sequence.

Captures a fresh JPEG for each part and emits per-frame timing diagnostics.

Returns: NetX status code.

Return values

NX_SUCCESS	The configured frame sequence completed.
NX_NOT_SUCCESSFUL	Capture or socket transmission failed.

Precondition: The HTTP socket is connected.; The selected camera backend is initialized.

Postcondition: Every successful frame is emitted as one complete multipart section.; Capture failures emit backend diagnostics before return.

Note: Clients reconnect after the bounded sequence or any failure.

Since: 0.1.0

Definition at line 325 of file c6_cam_net.c.

References c6_cam_camera_capture_jpeg(), c6_cam_camera_report_last_error(), c6_cam_put_u32(), c6_cam_puts(), c6_cam_frame_timing_t::capture_ms, c6_cam_frame_timing_t::convert_ms, c6_cam_frame_timing_t::encode_ms, internal_c6_cam_append(), internal_c6_cam_append_u32(), internal_c6_cam_http_send(), k_c6_cam_stream_frames, k_ra8_ok, and RA8_INTERNAL.

Referenced by internal_c6_cam_http_dispatch().

◆ internal_c6_cam_net_create()

UINT internal_c6_cam_net_create ( void )

static

Create the static NetX packet pool and IP instance.

Enables ARP, UDP, TCP, and ICMP over the already-bound C6 Ethernet driver.

Returns: NetX status code.

Return values

NX_SUCCESS	All required NetX objects and protocols are ready.
NX_NOT_SUCCESSFUL	A NetX creation or enable operation failed.

Precondition: nx_system_initialize has completed.; Static pool, stack, and ARP storage are not owned by another NetX instance.

Postcondition: On success, s_pool and s_ip are initialized.; On failure, no later protocol-enable step is attempted.

Note: Exact non-success codes are propagated from NetX.

Since: 0.1.0

Definition at line 70 of file c6_cam_net.c.

References k_c6_cam_net_ip_prio, k_c6_cam_net_pkt_payload, nx_ether_driver_c6(), RA8_INTERNAL, s_arp_cache, s_ip, s_ip_name, s_ip_stack, s_pool, s_pool_mem, and s_pool_name.

Referenced by c6_cam_net_up().

◆ internal_c6_cam_request_is()

bool internal_c6_cam_request_is	(	const char *	request,
		uint32_t	bytes,
		const char *	path )

static

Match a bounded HTTP GET request path.

Compares the request target exactly while accepting a query suffix.

Parameters

[in]	request	Raw request bytes.
[in]	bytes	Available request-byte count.
[in]	path	NUL-terminated path to match.

Returns: Match result.

Return values

true	The request is a GET for path with optional query text.
false	The method, length, or path does not match.

Precondition: request addresses at least bytes readable bytes.; path is nonnull and NUL-terminated.

Postcondition: Request and path storage remain unchanged.; No bytes beyond the supplied request bound are read.

Note: HTTP decoding beyond this narrow routing grammar is intentionally absent.

Since: 0.1.0

Definition at line 391 of file c6_cam_net.c.

References k_c6_cam_http_get_min, and memcmp().

Referenced by internal_c6_cam_http_dispatch().

Variable Documentation

◆ s_arp_cache

uint8_t s_arp_cache[k_c6_cam_net_arp_bytes]

static

Definition at line 34 of file c6_cam_net.c.

◆ s_dhcp

NX_DHCP s_dhcp

static

Definition at line 35 of file c6_cam_net.c.

Referenced by c6_cam_net_up(), priv_net_dhcp(), and priv_net_dhcp().

◆ s_dhcp_name

CHAR s_dhcp_name[] = "c6_cam_dhcp"

static

Definition at line 39 of file c6_cam_net.c.

Referenced by c6_cam_net_up(), priv_net_dhcp(), and priv_net_dhcp().

◆ s_http_socket

NX_TCP_SOCKET s_http_socket

static

Definition at line 36 of file c6_cam_net.c.

Referenced by c6_cam_http_serve(), internal_c6_cam_http_handle(), and internal_c6_cam_http_send().

◆ s_ip

NX_IP s_ip

static

Definition at line 32 of file c6_cam_net.c.

◆ s_ip_name

CHAR s_ip_name[] = "c6_cam_ip"

static

Definition at line 38 of file c6_cam_net.c.

Referenced by demo_netx_bring_up(), demo_netx_create_ip(), internal_c6_cam_net_create(), internal_demo_netx_bring_up(), priv_net_create_ip(), and priv_net_create_ip().

◆ s_ip_stack

uint8_t s_ip_stack[k_c6_cam_net_ip_stack]

static

Definition at line 33 of file c6_cam_net.c.

◆ s_page

const char s_page[]

static

Initial value:

                       =
"<!doctype html><html><head><meta charset=utf-8>"
"<meta name=viewport content='width=device-width,initial-scale=1'>"
"<title>EK-RA8D2 Camera</title><style>body{margin:0;background:#111;color:#eee;"
"font:16px system-ui;display:grid;place-items:center;min-height:100vh}main{text-align:center}"
"img{width:min(96vw,960px);height:auto;image-rendering:auto;border:1px solid #555}"
"small{display:block;margin-top:.5rem;color:#aaa}audio{margin-top:1rem}</style></head><body><main>"
"<h1>EK-RA8D2 / OV5640</h1><img id=stream src=/stream.mjpg alt='live camera'>"
"<small>bounded multipart MJPEG stream with automatic reconnect</small>"
"<audio controls src=/audio.wav></audio>"
"<small>latest rolling one-second onboard MIC1 recording</small>"
"<script>const s=document.getElementById('stream');s.onerror=()=>{"
"setTimeout(()=>{s.src='/stream.mjpg?t='+Date.now()},1000)}</script>"
"</main></body></html>"

Definition at line 42 of file c6_cam_net.c.

Referenced by cm_draw_page(), cm_draw_progress_bar(), cm_draw_status_bar(), cm_handle_tap(), and internal_c6_cam_http_dispatch().

◆ s_pool

NX_PACKET_POOL s_pool

static

Definition at line 30 of file c6_cam_net.c.

◆ s_pool_mem

uint8_t s_pool_mem[k_c6_cam_net_pool_bytes]

static

Definition at line 31 of file c6_cam_net.c.

Referenced by internal_c6_cam_net_create(), priv_net_create_ip(), and priv_net_create_ip().

◆ s_pool_name

CHAR s_pool_name[] = "c6_cam_pool"

static

Definition at line 37 of file c6_cam_net.c.

Referenced by internal_c6_cam_net_create(), priv_net_create_ip(), and priv_net_create_ip().

◆ s_socket_name

CHAR s_socket_name[] = "c6_cam_http"

static

Definition at line 40 of file c6_cam_net.c.

Referenced by c6_cam_http_serve(), demo_netx_bring_up(), demo_tcp_connect(), and internal_demo_tcp_connect().

Enumerations

Functions

Variables

Detailed Description

Enumeration Type Documentation

◆ c6_cam_net_format_t

Function Documentation

◆ c6_cam_http_serve()

◆ c6_cam_net_up()

◆ internal_c6_cam_append()

◆ internal_c6_cam_append_u32()

◆ internal_c6_cam_http_audio()

◆ internal_c6_cam_http_dispatch()

◆ internal_c6_cam_http_frame()

◆ internal_c6_cam_http_handle()

◆ internal_c6_cam_http_response()

◆ internal_c6_cam_http_send()

◆ internal_c6_cam_http_stream()

◆ internal_c6_cam_net_create()

◆ internal_c6_cam_request_is()

Variable Documentation

◆ s_arp_cache

◆ s_dhcp

◆ s_dhcp_name

◆ s_http_socket

◆ s_ip

◆ s_ip_name

◆ s_ip_stack

◆ s_page

◆ s_pool

◆ s_pool_mem

◆ s_pool_name

◆ s_socket_name