[update] use 750Kbps as download speed and add shakehand before download

tools/flash_download.py

@@ -9,7 +9,7 @@ from pathlib import Path
 class FlashDownloader:
     def __init__(self):
         self.port = None
-        self.baudrate = 2000000  # 默认2Mbps
+        self.baudrate = 750000  # 默认750Kbps
         self.filename = None
         self.address = 0x00010000  # 默认地址
         self.check = False
@@ -18,7 +18,7 @@ class FlashDownloader:
     def parse_arguments(self):
         parser = argparse.ArgumentParser(description='UART Flash Downloader')
         parser.add_argument('--COMX', required=True, help='COM port (e.g. COM3)')
-        parser.add_argument('--BAUDRATE', type=int, help='Baud rate (default: 2000000)')
+        parser.add_argument('--BAUDRATE', type=int, help='Baud rate (default: 750000)')
         parser.add_argument('--file', help='File to download')
         parser.add_argument('--ADDR', type=lambda x: int(x, 0), help='Download address (hex/dec)')
         parser.add_argument('--CHECK', action='store_true', help='Enable readback verification')
@@ -64,8 +64,11 @@ class FlashDownloader:
         self.ser.dtr = False  # DTR拉高
         time.sleep(0.1)       # 等待100ms
         self.ser.rts = False  # RTS拉高
-        time.sleep(0.1)       # 等待100ms
+        # time.sleep(0.5)       # 等待500ms
         print("Pre-erase signals set")
+        shakehand = self.ser.read(4)
+        print("shakehand=", shakehand)
+        return shakehand == b'\x55\x55\x55\x55'
 
     def control_signals_post_download(self):
         """下载完成后的信号控制"""
@@ -236,7 +239,9 @@ class FlashDownloader:
         print(f"Preparing to download {len(file_data)} bytes from {self.filename} to 0x{self.address:08X}")
 
         # 擦除前的信号控制
-        self.control_signals_pre_erase()
+        if not self.control_signals_pre_erase():
+            print("shake hands failed")
+            sys.exit(1)
 
         # 擦除Flash (擦除足够的空间)
         erase_size = ((len(file_data) + 4095) // 4096) * 4096  # 假设擦除块大小为4KB