example common_components: fixed GPIO max range for ESP32-C2

examples/common_components/env_caps/esp32c2/Kconfig.env_caps

@@ -4,7 +4,7 @@ config ENV_GPIO_RANGE_MIN
 
 config ENV_GPIO_RANGE_MAX
     int
-    default 19
+    default 20
 
 config ENV_GPIO_IN_RANGE_MAX
     int

examples/network/bridge/CMakeLists.txt

@@ -1,6 +1,6 @@
 # The following lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(bridge)

examples/network/bridge/README.md

@@ -13,7 +13,24 @@ Performance of this type of "software" bridge is limited by the performance of E
 
 You need one ESP32 with at least two Ethernet ports and two PCs (or other Ethernet capable devices). Connect the network as shown in figure below, configure PC#1 as DHCP server and PC#2 as DHCP client.
 
-![example network](docs/network.png)
+```mermaid
+graph TD;
+   classDef classPing fill:#0000,stroke-width:0px;
+   esp32["ESP32 w/ 2 bridged<br/>Ethernet ports<br/>(DHCP Client)"];
+   pc1["PC#1<br/>(DHCP Server)"];
+   pc2["PC#2<br/>(DHCP Client)"];
+   ping1["ping"]:::classPing
+   ping2["ping"]:::classPing
+   ping3["ping"]:::classPing
+   esp32 -.- ping1;
+   ping1 -.- pc1;
+   esp32 == Eth === pc2;
+   esp32 == Eth === pc1;
+   esp32 -.- ping2;
+   ping2 -.- pc2;
+   pc1 <-.- ping3;
+   pc2 <-.- ping3;
+```
 
 The work flow of the example is then as follows:
 

examples/network/bridge/main/bridge_example_main.c

@@ -301,10 +301,11 @@ void app_main(void)
         .base = &esp_netif_br_config,
         .stack = ESP_NETIF_NETSTACK_DEFAULT_BR,
     };
+    // Bridge configuration
     bridgeif_config_t bridgeif_config = {
-        .max_fdb_dyn_entries = 10,
-        .max_fdb_sta_entries = 2,
-        .max_ports = port_cnt
+        .max_fdb_dyn_entries = 10, // maximum number of address entries in dynamic forwarding database
+        .max_fdb_sta_entries = 2,  // maximum number of address entries in static forwarding database
+        .max_ports = port_cnt      // maximum number of ports the bridge can consist of
     };
     esp_netif_br_config.bridge_info = &bridgeif_config;
     // Set MAC address of bridge interface the same as the Ethernet interface