feat(modem): Add enhanced URC observer API

This commit is contained in:
David Cermak
2025-09-04 10:46:30 +02:00
parent 134247d88f
commit 4889dd6fcb
7 changed files with 441 additions and 41 deletions

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@@ -1,5 +1,5 @@
/*
* SPDX-FileCopyrightText: 2022-2024 Espressif Systems (Shanghai) CO LTD
* SPDX-FileCopyrightText: 2022-2025 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Unlicense OR CC0-1.0
*/
@@ -97,10 +97,21 @@ void wakeup_modem(void)
}
#ifdef CONFIG_ESP_MODEM_URC_HANDLER
command_result handle_urc(uint8_t *data, size_t len)
esp_modem::DTE::UrcConsumeInfo handle_enhanced_urc(const esp_modem::DTE::UrcBufferInfo &info)
{
ESP_LOG_BUFFER_HEXDUMP("on_read", data, len, ESP_LOG_INFO);
return command_result::TIMEOUT;
// Log buffer information for debugging
ESP_LOGI(TAG, "URC Buffer Info: total_size=%zu, processed_offset=%zu, new_data_size=%zu, command_active=%s",
info.buffer_total_size, info.processed_offset, info.new_data_size,
info.is_command_active ? "true" : "false");
// Log the new data content
if (info.new_data_size > 0) {
ESP_LOG_BUFFER_HEXDUMP("on_read", info.new_data_start, info.new_data_size, ESP_LOG_INFO);
}
// For console example, we just log and don't consume anything
// This allows the data to be processed by command handlers
return {esp_modem::DTE::UrcConsumeResult::CONSUME_NONE, 0};
}
#endif
@@ -381,14 +392,14 @@ extern "C" void app_main(void)
CHECK_ERR(dce->reset(), ESP_LOGI(TAG, "OK"));
});
#ifdef CONFIG_ESP_MODEM_URC_HANDLER
const ConsoleCommand HandleURC("urc", "toggle urc handling", no_args, [&](ConsoleCommand * c) {
const ConsoleCommand HandleURC("urc", "toggle enhanced urc handling", no_args, [&](ConsoleCommand * c) {
static int cnt = 0;
if (++cnt % 2) {
ESP_LOGI(TAG, "Adding URC handler");
dce->set_urc(handle_urc);
ESP_LOGI(TAG, "Adding enhanced URC handler");
dce->set_enhanced_urc(handle_enhanced_urc);
} else {
ESP_LOGI(TAG, "URC removed");
dce->set_urc(nullptr);
ESP_LOGI(TAG, "Enhanced URC removed");
dce->set_enhanced_urc(nullptr);
}
return 0;
});

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@@ -103,6 +103,11 @@ public:
{
dte->set_urc_cb(on_read_cb);
}
void set_enhanced_urc(esp_modem::DTE::enhanced_urc_cb enhanced_cb)
{
dte->set_enhanced_urc_cb(enhanced_cb);
}
#endif
/**

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@@ -1,5 +1,5 @@
/*
* SPDX-FileCopyrightText: 2021-2024 Espressif Systems (Shanghai) CO LTD
* SPDX-FileCopyrightText: 2021-2025 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
@@ -115,6 +115,42 @@ public:
{
command_cb.urc_handler = std::move(line_cb);
}
/**
* @brief Enhanced URC handler with buffer consumption control
* @param buffer_info Information about the current buffer state
* @return Information about how much of the buffer to consume
*/
struct UrcBufferInfo {
const uint8_t* buffer_start; // Start of entire buffer
size_t buffer_total_size; // Total buffer size
size_t processed_offset; // Offset of already processed data
size_t new_data_size; // Size of new data since last call
const uint8_t* new_data_start; // Pointer to start of new data
bool is_command_active; // Whether a command is currently waiting for response
};
enum class UrcConsumeResult {
CONSUME_NONE, // Don't consume anything, continue waiting
CONSUME_PARTIAL, // Consume only part of the buffer
CONSUME_ALL // Consume entire buffer
};
struct UrcConsumeInfo {
UrcConsumeResult result;
size_t consume_size; // How many bytes to consume (0 = none, SIZE_MAX = all)
};
typedef std::function<UrcConsumeInfo(const UrcBufferInfo &)> enhanced_urc_cb;
/**
* @brief Set enhanced URC callback with buffer consumption control
* @param enhanced_cb Enhanced callback that can control buffer consumption
*/
void set_enhanced_urc_cb(enhanced_urc_cb enhanced_cb)
{
command_cb.enhanced_urc_handler = std::move(enhanced_cb);
}
#endif
/**
@@ -171,6 +207,33 @@ private:
[[nodiscard]] bool exit_cmux(); /*!< Exit of CMUX mode and cleanup */
void exit_cmux_internal(); /*!< Cleanup CMUX */
#ifdef CONFIG_ESP_MODEM_URC_HANDLER
/**
* @brief Buffer state tracking for enhanced URC processing
*/
struct BufferState {
size_t total_processed = 0; /*!< Total bytes processed by URC handlers */
size_t last_urc_processed = 0; /*!< Last offset processed by URC */
bool command_waiting = false; /*!< Whether command is waiting for response */
size_t command_start_offset = 0; /*!< Where current command response started */
} buffer_state;
/**
* @brief Update buffer state when new data arrives
* @param new_data_size Size of new data added to buffer
*/
void update_buffer_state(size_t new_data_size);
/**
* @brief Create URC buffer information for enhanced handlers
* @param data Buffer data pointer
* @param consumed Already consumed bytes
* @param len New data length
* @return UrcBufferInfo structure with complete buffer context
*/
UrcBufferInfo create_urc_info(uint8_t* data, size_t consumed, size_t len);
#endif
Lock internal_lock{}; /*!< Locks DTE operations */
unique_buffer buffer; /*!< DTE buffer */
std::shared_ptr<CMux> cmux_term; /*!< Primary terminal for this DTE */
@@ -216,6 +279,7 @@ private:
struct command_cb {
#ifdef CONFIG_ESP_MODEM_URC_HANDLER
got_line_cb urc_handler {}; /*!< URC callback if enabled */
enhanced_urc_cb enhanced_urc_handler {}; /*!< Enhanced URC callback with consumption control */
#endif
static const size_t GOT_LINE = SignalGroup::bit0; /*!< Bit indicating response available */
got_line_cb got_line; /*!< Supplied command callback */
@@ -223,7 +287,7 @@ private:
char separator{}; /*!< Command reply separator (end of line/processing unit) */
command_result result{}; /*!< Command return code */
SignalGroup signal; /*!< Event group used to signal request-response operations */
bool process_line(uint8_t *data, size_t consumed, size_t len); /*!< Lets the processing callback handle one line (processing unit) */
bool process_line(uint8_t *data, size_t consumed, size_t len, DTE* dte = nullptr); /*!< Lets the processing callback handle one line (processing unit) */
bool wait_for_line(uint32_t time_ms) /*!< Waiting for command processing */
{
return signal.wait_any(command_cb::GOT_LINE, time_ms);

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@@ -65,6 +65,10 @@ void DTE::set_command_callbacks()
{
primary_term->set_read_cb([this](uint8_t *data, size_t len) {
Scoped<Lock> l(command_cb.line_lock);
#ifdef CONFIG_ESP_MODEM_URC_HANDLER
// Update buffer state when new data arrives
update_buffer_state(len);
#endif
#ifndef CONFIG_ESP_MODEM_URC_HANDLER
if (command_cb.got_line == nullptr || command_cb.result != command_result::TIMEOUT) {
return false; // this line has been processed already (got OK or FAIL previously)
@@ -80,7 +84,7 @@ void DTE::set_command_callbacks()
std::memcpy(inflatable.current(), data, len);
data = inflatable.begin();
}
if (command_cb.process_line(data, inflatable.consumed, len)) {
if (command_cb.process_line(data, inflatable.consumed, len, this)) {
return true;
}
// at this point we're sure that the data processing hasn't finished,
@@ -92,7 +96,7 @@ void DTE::set_command_callbacks()
inflatable.consumed += len;
return false;
#else
if (command_cb.process_line(data, 0, len)) {
if (command_cb.process_line(data, 0, len, this)) {
return true;
}
// cannot inflate and the processing hasn't finishes in the first iteration, but continue
@@ -105,7 +109,7 @@ void DTE::set_command_callbacks()
if (buffer.size > buffer.consumed) {
data = buffer.get();
len = primary_term->read(data + buffer.consumed, buffer.size - buffer.consumed);
if (command_cb.process_line(data, buffer.consumed, len)) {
if (command_cb.process_line(data, buffer.consumed, len, this)) {
return true;
}
buffer.consumed += len;
@@ -121,7 +125,7 @@ void DTE::set_command_callbacks()
inflatable.grow(inflatable.consumed + len);
}
len = primary_term->read(inflatable.current(), len);
if (command_cb.process_line(inflatable.begin(), inflatable.consumed, len)) {
if (command_cb.process_line(inflatable.begin(), inflatable.consumed, len, this)) {
return true;
}
inflatable.consumed += len;
@@ -150,10 +154,19 @@ void DTE::set_command_callbacks()
command_result DTE::command(const std::string &command, got_line_cb got_line, uint32_t time_ms, const char separator)
{
Scoped<Lock> l1(internal_lock);
#ifdef CONFIG_ESP_MODEM_URC_HANDLER
// Track command start
buffer_state.command_waiting = true;
buffer_state.command_start_offset = buffer_state.total_processed;
#endif
command_cb.set(got_line, separator);
primary_term->write((uint8_t *)command.c_str(), command.length());
command_cb.wait_for_line(time_ms);
command_cb.set(nullptr);
#ifdef CONFIG_ESP_MODEM_URC_HANDLER
// Track command end
buffer_state.command_waiting = false;
#endif
buffer.consumed = 0;
#ifdef CONFIG_ESP_MODEM_USE_INFLATABLE_BUFFER_IF_NEEDED
inflatable.deflate();
@@ -365,18 +378,54 @@ void DTE::on_read(got_line_cb on_read_cb)
});
}
bool DTE::command_cb::process_line(uint8_t *data, size_t consumed, size_t len)
bool DTE::command_cb::process_line(uint8_t *data, size_t consumed, size_t len, DTE* dte)
{
// returning true indicates that the processing finished and lower layers can destroy the accumulated buffer
#ifdef CONFIG_ESP_MODEM_URC_HANDLER
bool consume_buffer = false;
if (urc_handler) {
consume_buffer = urc_handler(data, consumed + len) != command_result::TIMEOUT;
// Call enhanced URC handler if registered
if (enhanced_urc_handler && dte) {
// Create buffer info for enhanced URC handler
UrcBufferInfo buffer_info = dte->create_urc_info(data, consumed, len);
// Call enhanced URC handler
UrcConsumeInfo consume_info = enhanced_urc_handler(buffer_info);
// Handle consumption control
switch (consume_info.result) {
case UrcConsumeResult::CONSUME_NONE:
// Don't consume anything, continue with command processing
break;
case UrcConsumeResult::CONSUME_PARTIAL:
// Consume only specified amount
dte->buffer_state.last_urc_processed += consume_info.consume_size;
// Adjust data pointers for command processing
data += consume_info.consume_size;
consumed = (consumed + len) - consume_info.consume_size;
len = 0;
break;
case UrcConsumeResult::CONSUME_ALL:
// Consume entire buffer
dte->buffer_state.last_urc_processed = consumed + len;
return true; // Signal buffer consumption
}
}
if (result != command_result::TIMEOUT || got_line == nullptr) {
return consume_buffer; // this line has been processed already (got OK or FAIL previously)
// Fallback to legacy URC handler if enhanced handler not set
if (urc_handler) {
bool consume_buffer = urc_handler(data, consumed + len) != command_result::TIMEOUT;
if (result != command_result::TIMEOUT || got_line == nullptr) {
return consume_buffer; // this line has been processed already (got OK or FAIL previously)
}
}
#endif
// Continue with normal command processing
if (result != command_result::TIMEOUT || got_line == nullptr) {
return false; // Command processing continues
}
if (memchr(data + consumed, separator, len)) {
result = got_line(data, consumed + len);
if (result == command_result::OK || result == command_result::FAIL) {
@@ -423,3 +472,22 @@ void DTE::extra_buffer::grow(size_t need_size)
*/
unique_buffer::unique_buffer(size_t size):
data(std::make_unique<uint8_t[]>(size)), size(size), consumed(0) {}
#ifdef CONFIG_ESP_MODEM_URC_HANDLER
void DTE::update_buffer_state(size_t new_data_size)
{
buffer_state.total_processed += new_data_size;
}
DTE::UrcBufferInfo DTE::create_urc_info(uint8_t* data, size_t consumed, size_t len)
{
return {
.buffer_start = data,
.buffer_total_size = consumed + len,
.processed_offset = buffer_state.last_urc_processed,
.new_data_size = (consumed + len) - buffer_state.last_urc_processed,
.new_data_start = data + buffer_state.last_urc_processed,
.is_command_active = buffer_state.command_waiting
};
}
#endif

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@@ -0,0 +1,152 @@
# ESP Modem Enhanced URC Test
## Overview
This test validates the enhanced URC (Unsolicited Result Code) interface with buffer consumption control. It demonstrates the new `set_enhanced_urc()` API that provides granular control over buffer consumption and complete buffer visibility.
## Test Configuration
- **Target**: ESP-AT device with HTTP server
- **UART**: 115200 baud, 8N1, TX=17, RX=18
- **Buffer Size**: 1024 bytes
- **Timeout**: 15 seconds
## Test Cases
### 1. Enhanced URC Handler Registration
- **Objective**: Verify enhanced URC handler can be registered
- **Method**: Call `set_enhanced_urc()` with custom handler
- **Expected**: Handler receives `UrcBufferInfo` with complete buffer context
### 2. Buffer Visibility
- **Objective**: Verify URC handler receives complete buffer information
- **Method**: Log buffer state information in handler
- **Expected**: Handler receives `buffer_start`, `buffer_total_size`, `processed_offset`, `new_data_size`, `is_command_active`
### 3. Granular Consumption Control
- **Objective**: Verify handler can consume partial buffer data
- **Method**: Process HTTP URCs line-by-line using `CONSUME_PARTIAL`
- **Expected**: Each complete line is consumed individually, remaining data preserved
### 4. Multi-part Response Handling
- **Objective**: Verify handling of chunked HTTP responses
- **Method**: Process 9 HTTP chunks from ESP-AT server
- **Expected**: All chunks processed correctly with proper offset tracking
### 5. Transfer Completion Detection
- **Objective**: Verify detection of transfer completion message
- **Method**: Search for "Transfer completed" in buffer
- **Expected**: Completion detected and event group signaled
### 6. Command State Awareness
- **Objective**: Verify handler knows command state
- **Method**: Check `is_command_active` flag during processing
- **Expected**: Flag correctly reflects command state
## Test Implementation
The test uses an ESP-AT device running an HTTP server that sends chunked responses. The enhanced URC handler processes each HTTP URC line individually and detects completion.
### Key Components
```cpp
// Enhanced URC handler registration
set_enhanced_urc(handle_enhanced_urc);
// Handler implementation
static esp_modem::DTE::UrcConsumeInfo handle_enhanced_urc(const esp_modem::DTE::UrcBufferInfo& info)
{
// Process HTTP URCs with granular consumption control
if (line.starts_with("+HTTPCGET:")) {
// Consume this line only
return {esp_modem::DTE::UrcConsumeResult::CONSUME_PARTIAL, line_end + 1};
}
// Check for completion
if (buffer.find("Transfer completed") != std::string_view::npos) {
xEventGroupSetBits(s_event_group, transfer_completed);
return {esp_modem::DTE::UrcConsumeResult::CONSUME_ALL, 0};
}
return {esp_modem::DTE::UrcConsumeResult::CONSUME_NONE, 0};
}
```
## Example Output
### Successful Test Run
```
I (908) urc_test: Starting Enhanced URC Test
I (938) urc_test: Start HTTP server...(0)
I (948) urc_test: HTTP GET...(43)
I (1228) urc_test: HTTP URC: +HTTPCGET:27,=== Async Response #4 ===
I (2778) urc_test: HTTP URC: +HTTPCGET:61,[1/9] [633135 ms] This is a simulated slow server response.
I (4288) urc_test: HTTP URC: +HTTPCGET:71,[2/9] [634639 ms] Chunk 1: The ESP-AT HTTP server is demonstrating...
I (5788) urc_test: HTTP URC: +HTTPCGET:73,[3/9] [636143 ms] Chunk 2: ...asynchronous chunked transfer encoding...
I (7288) urc_test: HTTP URC: +HTTPCGET:72,[4/9] [637647 ms] Chunk 3: ...with artificial delays between chunks...
I (8788) urc_test: HTTP URC: +HTTPCGET:74,[5/9] [639151 ms] Chunk 4: ...to simulate real-world network conditions.
I (10288) urc_test: HTTP URC: +HTTPCGET:62,[6/9] [640655 ms] Chunk 5: Processing data... please wait...
I (11788) urc_test: HTTP URC: +HTTPCGET:63,[7/9] [642159 ms] Chunk 6: Still processing... almost done...
I (13288) urc_test: HTTP URC: +HTTPCGET:61,[8/9] [643663 ms] Chunk 7: Final chunk - transfer complete!
I (14758) urc_test: HTTP URC: +HTTPCGET:43,[9/9] [645168 ms] === END OF RESPONSE ===
I (15258) urc_test: Transfer completed detected in buffer!
I (15298) urc_test: Enhanced URC test completed successfully!
I (15308) urc_test: The enhanced URC handler successfully processed all HTTP chunks
I (15308) urc_test: with granular buffer consumption control
```
### Debug Output (with ESP_LOG_LEVEL_DEBUG)
```
D (958) urc_test: URC Buffer Info: total_size=43, processed_offset=0, new_data_size=43, command_active=false
D (958) urc_test: Buffer content (first 43 chars): AT+HTTPCGET="http://127.0.0.1:8080/async"
D (968) urc_test: Other data: AT+HTTPCGET="http://127.0.0.1:8080/async"
D (1218) urc_test: URC Buffer Info: total_size=85, processed_offset=43, new_data_size=42, command_active=false
D (1228) urc_test: Consuming 40 bytes (line_end=82, processed_offset=43)
D (2778) urc_test: Consuming 76 bytes (line_end=158, processed_offset=83)
```
### Failed Test (Timeout)
```
I (908) urc_test: Starting Enhanced URC Test
I (948) urc_test: HTTP GET...(43)
E (15385) urc_test: Enhanced URC test timed out
I (15385) urc_test: Enhanced URC test done
```
## Test Validation
### Success Criteria
- All 9 HTTP chunks processed successfully
- Transfer completion detected within 15 seconds
- No buffer arithmetic errors (no negative `new_data_size`)
- Proper consumption control (line-by-line processing)
### Failure Indicators
- Test timeout (15 seconds)
- Buffer arithmetic errors (negative `new_data_size`)
- Missing HTTP chunks
- Transfer completion not detected
## Dependencies
- ESP-AT device with HTTP server capability
- UART connection configured
- `CONFIG_ESP_MODEM_URC_HANDLER=y`
- FreeRTOS event groups
## Build and Run
```bash
idf.py build
idf.py flash monitor
```
## Comparison with Legacy URC
| Feature | Legacy URC | Enhanced URC |
|---------|------------|--------------|
| Buffer Consumption | All or nothing | Granular (partial) |
| Buffer Visibility | None | Complete context |
| Command State | Unknown | Known (`is_command_active`) |
| Processing State | Unknown | Tracked (`processed_offset`) |
| Multi-part Support | Limited | Full support |

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@@ -3,7 +3,26 @@
*
* SPDX-License-Identifier: Unlicense OR CC0-1.0
*/
/**
* @file urc_test.cpp
* @brief Enhanced URC (Unsolicited Result Code) Test
*
* This test demonstrates the new enhanced URC interface with buffer consumption control.
* It tests the following features:
*
* 1. Enhanced URC Handler Registration: Uses set_enhanced_urc() instead of set_urc()
* 2. Buffer Visibility: URC handler receives complete buffer information
* 3. Granular Consumption Control: Handler can consume none, partial, or all buffer data
* 4. Processing State Awareness: Handler knows what data is new vs. already processed
* 5. Command State Awareness: Handler knows if a command is currently active
*
* The test works with ESP-AT HTTP server that sends chunked responses, demonstrating
* how the enhanced URC handler can process multi-part responses with precise control
* over buffer consumption.
*/
#include <cstring>
#include <algorithm>
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
#include "esp_netif.h"
@@ -67,7 +86,7 @@ public:
bool http_get(const std::string &url)
{
std::string command = "AT+HTTPCGET=\"" + url + "\"\r\n";
set_urc(handle_urc);
set_enhanced_urc(handle_enhanced_urc);
auto ret = dte->write(esp_modem::DTE_Command(command));
ESP_LOGI(TAG, "HTTP GET...(%d)", static_cast<int>(ret));
return ret > 0;
@@ -82,25 +101,88 @@ public:
static constexpr int transfer_completed = 1;
private:
static esp_modem::command_result handle_urc(uint8_t *data, size_t len)
static esp_modem::DTE::UrcConsumeInfo handle_enhanced_urc(const esp_modem::DTE::UrcBufferInfo &info)
{
static int start_chunk = 0;
static int end_chunk = 0;
std::string_view chunk((const char*)data + start_chunk, len - start_chunk);
int newline = chunk.find('\n');
if (newline == std::string_view::npos) {
end_chunk = len; // careful, this grows buffer usage
printf(".");
return esp_modem::command_result::TIMEOUT;
// Log buffer information for debugging
ESP_LOGD(TAG, "URC Buffer Info: total_size=%zu, processed_offset=%zu, new_data_size=%zu, command_active=%s",
info.buffer_total_size, info.processed_offset, info.new_data_size,
info.is_command_active ? "true" : "false");
// Debug: Show buffer content (first 200 chars)
if (info.buffer_total_size > 0) {
size_t debug_len = std::min(info.buffer_total_size, (size_t)200);
ESP_LOGD(TAG, "Buffer content (first %zu chars): %.*s",
debug_len, (int)debug_len, (const char*)info.buffer_start);
}
printf("%.*s\n", newline, (char*)data + start_chunk);
start_chunk = end_chunk;
// check for the last one
constexpr char last_chunk[] = "Transfer completed";
if (memmem(data, len, last_chunk, sizeof(last_chunk) - 1) != nullptr) {
// Create string view of the entire buffer for processing
std::string_view buffer((const char*)info.buffer_start, info.buffer_total_size);
// First, check if we have the completion message anywhere in the buffer
if (buffer.find("Transfer completed") != std::string_view::npos) {
ESP_LOGI(TAG, "Transfer completed detected in buffer!");
xEventGroupSetBits(s_event_group, transfer_completed);
// Consume everything
return {esp_modem::DTE::UrcConsumeResult::CONSUME_ALL, 0};
}
return esp_modem::command_result::OK;
// Process from the last processed offset
size_t search_start = info.processed_offset;
// Look for complete lines starting from the processed offset
while (search_start < info.buffer_total_size) {
size_t line_end = buffer.find('\n', search_start);
if (line_end == std::string_view::npos) {
// No complete line found, wait for more data
ESP_LOGD(TAG, "Waiting for more data... (search_start=%zu, total_size=%zu)",
search_start, info.buffer_total_size);
return {esp_modem::DTE::UrcConsumeResult::CONSUME_NONE, 0};
}
// Found a complete line, process it
std::string_view line = buffer.substr(search_start, line_end - search_start);
// Remove carriage return if present
if (!line.empty() && line.back() == '\r') {
line.remove_suffix(1);
}
// Check if this is an HTTP URC
if (line.starts_with("+HTTPCGET:")) {
ESP_LOGI(TAG, "HTTP URC: %.*s", (int)line.length(), line.data());
// Check for transfer completion - look for "Transfer completed" anywhere in the line
if (line.find("Transfer completed") != std::string_view::npos) {
ESP_LOGI(TAG, "Transfer completed detected!");
xEventGroupSetBits(s_event_group, transfer_completed);
}
// Consume this line (including the newline)
size_t consume_size = line_end + 1 - info.processed_offset;
ESP_LOGD(TAG, "Consuming %zu bytes (line_end=%zu, processed_offset=%zu)",
consume_size, line_end, info.processed_offset);
return {esp_modem::DTE::UrcConsumeResult::CONSUME_PARTIAL, consume_size};
} else if (line.starts_with("+HTTPCGET")) {
// Partial HTTP URC, don't consume yet
ESP_LOGD(TAG, "Partial HTTP URC: %.*s", (int)line.length(), line.data());
return {esp_modem::DTE::UrcConsumeResult::CONSUME_NONE, 0};
} else if (!line.empty()) {
// Other data, log and consume
ESP_LOGD(TAG, "Other data: %.*s", (int)line.length(), line.data());
size_t consume_size = line_end + 1 - info.processed_offset;
return {esp_modem::DTE::UrcConsumeResult::CONSUME_PARTIAL, consume_size};
}
// Move to next line
search_start = line_end + 1;
}
// Processed all available data
ESP_LOGD(TAG, "Processed all available data");
return {esp_modem::DTE::UrcConsumeResult::CONSUME_NONE, 0};
}
};
@@ -131,8 +213,8 @@ extern "C" void app_main(void)
esp_modem_dte_config_t dte_config = ESP_MODEM_DTE_DEFAULT_CONFIG();
dte_config.dte_buffer_size = 1024;
dte_config.uart_config.tx_io_num = 18;
dte_config.uart_config.rx_io_num = 17;
dte_config.uart_config.tx_io_num = 17;
dte_config.uart_config.rx_io_num = 18;
auto uart_dte = esp_modem::create_uart_dte(&dte_config);
if (uart_dte == nullptr) {
ESP_LOGE(TAG, "Failed to create UART DTE");
@@ -144,15 +226,24 @@ extern "C" void app_main(void)
return;
}
ESP_LOGI(TAG, "Starting Enhanced URC Test");
ESP_LOGI(TAG, "This test demonstrates the new enhanced URC interface with buffer consumption control");
dce->start_http_server();
ESP_LOGI(TAG, "Sending HTTP GET request with enhanced URC handler");
dce->http_get("http://127.0.0.1:8080/async");
EventBits_t bits = xEventGroupWaitBits(s_event_group, 1, pdTRUE, pdFALSE, pdMS_TO_TICKS(15000));
if (bits & DCE::transfer_completed) {
ESP_LOGI(TAG, "Request finished!");
ESP_LOGI(TAG, "Enhanced URC test completed successfully!");
ESP_LOGI(TAG, "The enhanced URC handler successfully processed all HTTP chunks");
ESP_LOGI(TAG, "with granular buffer consumption control");
} else {
ESP_LOGE(TAG, "Enhanced URC test timed out");
}
dce->sync();
vEventGroupDelete(s_event_group);
ESP_LOGI(TAG, "Done");
ESP_LOGI(TAG, "Enhanced URC test done");
}

View File

@@ -38,6 +38,15 @@ work with commands differently. This might be useful to add some custom preproce
Please check the ``modem_console`` example with ``CONFIG_EXAMPLE_MODEM_DEVICE_SHINY=y`` configuration which demonstrates
overriding default ``command()`` method to implement URC processing in user space.
Enhanced URC (Unsolicited Result Code) Handling
------------------------------------------------
The ESP modem library provides two interfaces for handling URCs: a legacy callback-based interface and an enhanced interface with granular buffer consumption control. The enhanced interface, available through :cpp:func:`esp_modem::DCE_T::set_enhanced_urc`, provides complete buffer visibility and allows URC handlers to make precise decisions about buffer consumption. This is particularly useful for processing multi-part responses or when you need to consume only specific portions of the buffer while preserving other data for command processing.
The enhanced URC handler receives a :cpp:struct:`esp_modem::DTE::UrcBufferInfo` structure containing the complete buffer context, including what data has been processed, what's new, and whether a command is currently active. The handler returns a :cpp:struct:`esp_modem::DTE::UrcConsumeInfo` structure specifying how much of the buffer to consume: none (wait for more data), partial (consume specific amount), or all (consume entire buffer). This granular control enables sophisticated URC processing scenarios such as line-by-line parsing of chunked HTTP responses or selective processing based on command state.
For applications migrating from the legacy URC interface, the enhanced interface maintains backward compatibility while providing significantly more control over buffer management. The legacy :cpp:func:`esp_modem::DCE_T::set_urc` method continues to work as before, but new applications should consider using the enhanced interface for better buffer control and processing flexibility.
Create new communication interface
----------------------------------