add some code

main/boards/common/ml307_board.h

@@ -0,0 +1,29 @@
+#ifndef ML307_BOARD_H
+#define ML307_BOARD_H
+
+#include <memory>
+#include <at_modem.h>
+#include "board.h"
+
+
+class Ml307Board : public Board {
+protected:
+    std::unique_ptr<AtModem> modem_;
+    gpio_num_t tx_pin_;
+    gpio_num_t rx_pin_;
+    gpio_num_t dtr_pin_;
+
+    virtual std::string GetBoardJson() override;
+
+public:
+    Ml307Board(gpio_num_t tx_pin, gpio_num_t rx_pin, gpio_num_t dtr_pin = GPIO_NUM_NC);
+    virtual std::string GetBoardType() override;
+    virtual void StartNetwork() override;
+    virtual NetworkInterface* GetNetwork() override;
+    virtual const char* GetNetworkStateIcon() override;
+    virtual void SetPowerSaveMode(bool enabled) override;
+    virtual AudioCodec* GetAudioCodec() override { return nullptr; }
+    virtual std::string GetDeviceStatusJson() override;
+};
+
+#endif // ML307_BOARD_H