Merge pull request #413 from david-cermak/feat/new_modem_cmd

Added support for implementing user defined modules in standard C-API

components/esp_modem/examples/pppos_client/main/Kconfig.projbuild

@@ -48,6 +48,13 @@ menu "Example Configuration"
             bool "A7670"
             help
                 A7670X is Multi-Band LTE-FDD/LTE-TDD/GSM/GPRS/EDGE module.
+
+        config EXAMPLE_MODEM_DEVICE_CUSTOM
+            select ESP_MODEM_ADD_CUSTOM_MODULE
+            bool "Custom device"
+            help
+                This demonstrates use of a custom device in C-API.
+
     endchoice
 
     config EXAMPLE_MODEM_PPP_APN

components/esp_modem/examples/pppos_client/main/custom_module.hpp

@@ -0,0 +1,79 @@
+/*
+ * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
+#pragma once
+#include "cxx_include/esp_modem_api.hpp"
+#include "cxx_include/esp_modem_command_library_utils.hpp"
+
+/**
+ * @brief Definition of a custom module based on some already defined module
+ *          Here we use GenericModule, but you can use any kind of device
+ *          that is closer to your CustomModule.
+ */
+class SIM7600_WITH_TIME: public GenericModule {
+    /**
+     * @brief Need to reuse the constructors of our ancestor
+     */
+    using GenericModule::GenericModule;
+public:
+    /**
+     * @brief New command that is not defined in the GenericModule
+     */
+    command_result get_time(std::string &time)
+    {
+        return esp_modem::dce_commands::generic_get_string(dte.get(), "AT+CCLK?\r", time);
+    }
+
+    /**
+     * @brief This command is already defined in the GenericModule
+     *
+     * Here we just modify get_signal_quality() to return zeroes
+     * for demonstration purpose only, since it's called within this example
+     */
+    command_result get_signal_quality(int &rssi, int &ber) override
+    {
+        rssi = ber = 0;
+        return esp_modem::command_result::OK;
+    }
+
+};
+
+/**
+ * @brief esp_modem_create_custom_dce() needs to be defined, as it is called in C-API wrapper when creating esp_modem_dce
+ *
+ * This uses public factory function for creating a common DCE with our CustomModule. Creating raw DCE pointer is only needed
+ * for the C-API wrapper; C++API users would create DCE (any kind of smart pointer) directly with
+ * Factory::create_unique_dce_from<CustomModule>(dce_config, std::move(dte), netif);
+ */
+DCE *esp_modem_create_custom_dce(const esp_modem_dce_config_t *dce_config, std::shared_ptr<DTE> dte, esp_netif_t *netif)
+{
+    return dce_factory::Factory::create_unique_dce_from<SIM7600_WITH_TIME, DCE *>(dce_config, std::move(dte), netif);
+}
+
+/**
+ * @brief This API is only needed for extending standard C-API, since we added get_time() method to our CustomModule
+ *
+ * @note This header is included from esp_modem_c_api.cpp, so it could use ESP_MODEM_C_API_STR_MAX macro
+ * indicating maximum C-API string size
+ *
+ * @note In order to access the newly added API get_time(), we have to static_cast<> the GenericModule from DCE
+ * to our CustomModule.
+ * Alternatively we could use the modem Factory to build our specific DCE_T<CustomModule>, but in that case
+ * we couldn't use our C-API wrappers which expect DCE type, DCE_T<GenericModule> with lib commands (this alternative
+ * is cleaner, but more suitable for C++ users)
+ */
+extern "C" esp_err_t esp_modem_get_time(esp_modem_dce_t *dce_wrap, char *p_time)
+{
+    if (dce_wrap == nullptr || dce_wrap->dce == nullptr) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    std::string time{ESP_MODEM_C_API_STR_MAX};
+    auto ret = command_response_to_esp_err(static_cast<SIM7600_WITH_TIME *>(dce_wrap->dce->get_module())->get_time(time));
+    if (ret == ESP_OK && !time.empty()) {
+        strlcpy(p_time, time.c_str(), ESP_MODEM_C_API_STR_MAX);
+    }
+    return ret;
+}

components/esp_modem/examples/pppos_client/main/pppos_client_main.c

@@ -37,6 +37,10 @@ static const int CONNECT_BIT = BIT0;
 static const int GOT_DATA_BIT = BIT2;
 static const int USB_DISCONNECTED_BIT = BIT3; // Used only with USB DTE but we define it unconditionally, to avoid too many #ifdefs in the code
 
+#ifdef CONFIG_EXAMPLE_MODEM_DEVICE_CUSTOM
+esp_err_t esp_modem_get_time(esp_modem_dce_t *dce_wrap, char *p_time);
+#endif
+
 #if defined(CONFIG_EXAMPLE_SERIAL_CONFIG_USB)
 #include "esp_modem_usb_c_api.h"
 #include "esp_modem_usb_config.h"
@@ -192,6 +196,9 @@ void app_main(void)
 #elif CONFIG_EXAMPLE_MODEM_DEVICE_SIM7600 == 1
     ESP_LOGI(TAG, "Initializing esp_modem for the SIM7600 module...");
     esp_modem_dce_t *dce = esp_modem_new_dev(ESP_MODEM_DCE_SIM7600, &dte_config, &dce_config, esp_netif);
+#elif CONFIG_EXAMPLE_MODEM_DEVICE_CUSTOM == 1
+    ESP_LOGI(TAG, "Initializing esp_modem with custom module...");
+    esp_modem_dce_t *dce = esp_modem_new_dev(ESP_MODEM_DCE_CUSTOM, &dte_config, &dce_config, esp_netif);
 #else
     ESP_LOGI(TAG, "Initializing esp_modem for a generic module...");
     esp_modem_dce_t *dce = esp_modem_new(&dte_config, &dce_config, esp_netif);
@@ -258,6 +265,18 @@ void app_main(void)
     }
     ESP_LOGI(TAG, "Signal quality: rssi=%d, ber=%d", rssi, ber);
 
+#ifdef CONFIG_EXAMPLE_MODEM_DEVICE_CUSTOM
+    {
+        char time[64];
+        err = esp_modem_get_time(dce, time);
+        if (err != ESP_OK) {
+            ESP_LOGE(TAG, "esp_modem_get_time failed with %d %s", err, esp_err_to_name(err));
+            return;
+        }
+        ESP_LOGI(TAG, "esp_modem_get_time: %s", time);
+    }
+#endif
+
 #if CONFIG_EXAMPLE_SEND_MSG
     if (esp_modem_sms_txt_mode(dce, true) != ESP_OK || esp_modem_sms_character_set(dce) != ESP_OK) {
         ESP_LOGE(TAG, "Setting text mode or GSM character set failed");