fix(esp-modem) Make simple_cmux_client example configurable

* extended simple_cmux_client

* add the Descriptions as proposed by @david-cermak

* EXAMPLE_FLOW_CONTROL

Co-authored-by: Franz Höpfinger <krone-trailer@franzhoepfinger.de>

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

@@ -14,6 +14,14 @@ menu "Example Configuration"
             bool "BG96"
             help
                 Quectel BG96 is a series of LTE Cat M1/Cat NB1/EGPRS module.
+        config EXAMPLE_MODEM_DEVICE_SIM7000
+            bool "SIM7000"
+            help
+                SIM7000 is a Multi-Band LTE-FDD and GSM/GPRS/EDGE module.
+        config EXAMPLE_MODEM_DEVICE_SIM7070
+            bool "SIM7070"
+            help
+                SIM7070 is Multi-Band CAT M and NB IoT module.
         config EXAMPLE_MODEM_DEVICE_SIM7600
             bool "SIM7600"
             help
@@ -39,6 +47,50 @@ menu "Example Configuration"
         help
             Pin to unlock the SIM
 
+    choice EXAMPLE_FLOW_CONTROL
+        bool "Set preferred modem control flow"
+        default EXAMPLE_FLOW_CONTROL_NONE
+        help
+            Set the modem's preferred control flow
+
+        config EXAMPLE_FLOW_CONTROL_NONE
+            bool "No control flow"
+        config EXAMPLE_FLOW_CONTROL_SW
+            bool "SW control flow"
+        config EXAMPLE_FLOW_CONTROL_HW
+            bool "HW control flow"
+    endchoice
+
+    menu "UART Configuration"
+        config EXAMPLE_MODEM_UART_TX_PIN
+            int "TXD Pin Number"
+            default 25
+            range 0 31
+            help
+                Pin number of UART TX.
+
+        config EXAMPLE_MODEM_UART_RX_PIN
+            int "RXD Pin Number"
+            default 26
+            range 0 31
+            help
+                Pin number of UART RX.
+
+        config EXAMPLE_MODEM_UART_RTS_PIN
+            int "RTS Pin Number"
+            default 27
+            range 0 31
+            help
+                Pin number of UART RTS.
+
+        config EXAMPLE_MODEM_UART_CTS_PIN
+            int "CTS Pin Number"
+            default 23
+            range 0 31
+            help
+                Pin number of UART CTS.
+    endmenu
+    
     config EXAMPLE_USE_VFS_TERM
         bool "Use VFS terminal"
         default n

components/esp_modem/examples/simple_cmux_client/main/simple_cmux_client_main.cpp

@@ -21,6 +21,14 @@
 #include "esp_https_ota.h"      // For potential OTA configuration
 #include "vfs_resource/vfs_create.hpp"
 
+#if defined(CONFIG_EXAMPLE_FLOW_CONTROL_NONE)
+#define EXAMPLE_FLOW_CONTROL ESP_MODEM_FLOW_CONTROL_NONE
+#elif defined(CONFIG_EXAMPLE_FLOW_CONTROL_SW)
+#define EXAMPLE_FLOW_CONTROL ESP_MODEM_FLOW_CONTROL_SW
+#elif defined(CONFIG_EXAMPLE_FLOW_CONTROL_HW)
+#define EXAMPLE_FLOW_CONTROL ESP_MODEM_FLOW_CONTROL_HW
+#endif
+
 #define BROKER_URL "mqtt://mqtt.eclipseprojects.io"
 
 
@@ -39,6 +47,12 @@ extern "C" void app_main(void)
 
     /* Configure and create the DTE */
     esp_modem_dte_config_t dte_config = ESP_MODEM_DTE_DEFAULT_CONFIG();
+    /* setup UART specific configuration based on kconfig options */
+    dte_config.uart_config.tx_io_num = CONFIG_EXAMPLE_MODEM_UART_TX_PIN;
+    dte_config.uart_config.rx_io_num = CONFIG_EXAMPLE_MODEM_UART_RX_PIN;
+    dte_config.uart_config.rts_io_num = CONFIG_EXAMPLE_MODEM_UART_RTS_PIN;
+    dte_config.uart_config.cts_io_num = CONFIG_EXAMPLE_MODEM_UART_CTS_PIN;
+    dte_config.uart_config.flow_control = EXAMPLE_FLOW_CONTROL;
 #if CONFIG_EXAMPLE_USE_VFS_TERM == 1
     /* The VFS terminal is just a demonstration of using an abstract file descriptor
      * which implements non-block reads, writes and selects to communicate with esp-modem.
@@ -71,6 +85,10 @@ extern "C" void app_main(void)
     std::unique_ptr<DCE> dce = create_BG96_dce(&dce_config, dte, esp_netif);
 #elif CONFIG_EXAMPLE_MODEM_DEVICE_SIM800 == 1
     std::unique_ptr<DCE> dce = create_SIM800_dce(&dce_config, dte, esp_netif);
+#elif CONFIG_EXAMPLE_MODEM_DEVICE_SIM7000 == 1
+    std::unique_ptr<DCE> dce = create_SIM7000_dce(&dce_config, dte, esp_netif);
+#elif CONFIG_EXAMPLE_MODEM_DEVICE_SIM7070 == 1
+    std::unique_ptr<DCE> dce = create_SIM7070_dce(&dce_config, dte, esp_netif);
 #elif CONFIG_EXAMPLE_MODEM_DEVICE_SIM7600 == 1
     std::unique_ptr<DCE> dce = create_SIM7600_dce(&dce_config, dte, esp_netif);
 #else
@@ -78,6 +96,17 @@ extern "C" void app_main(void)
 #endif
     assert(dce);
 
+    if(dte_config.uart_config.flow_control == ESP_MODEM_FLOW_CONTROL_HW)
+    {
+        if (command_result::OK != dce->set_flow_control(2, 2)) {
+            ESP_LOGE(TAG, "Failed to set the set_flow_control mode");
+            return;
+        }
+        ESP_LOGI(TAG, "set_flow_control OK");
+    } else {
+        ESP_LOGI(TAG, "not set_flow_control, because 2-wire mode active.");
+    }
+
     /* Setup basic operation mode for the DCE (pin if used, CMUX mode) */
 #if CONFIG_EXAMPLE_NEED_SIM_PIN == 1
     bool pin_ok = true;