Arduino WiFi Shield无法发送整个TCP数据包

Question

I have an Arduino Uno R3 with an Arduino WiFi shield. The WiFi shield has the most current firmware (V1.1.0). I am trying to send a packet to the router that is about 900 bytes (the packet is for setting up a UPnP port map). This packet is stored in program memory to conserve SRAM. Using strcat_P , I can pull the packet from memory into a buffer and send it using the WiFiClient library (TCP).

The problem is that I can't send the whole packet. For testing, I just send the packet to my computer located on the same LAN where I use a packet sniffer to view the packet. Using WiFiClient.write(), I get differing performance depending on the size of the buffer I use. I seem to get the best performance calling WiFiClient.write() with a buffer size of 80 repeatedly until the whole packet has been "sent". Anything greater than about 80 will cause blank packets on the other end. However, with 80, I usually only see about 500 bytes get transmitted. The packet always gets cut off at an arbitrary point. Does anyone know what could be causing this?

I've did a lot of Googling, and I see others having similar problems. I have never ran across a solution, though.

Answer 1

I know this is old, but I recently found this article which addresses the issue you are describing.

tl;dr - You can only write 90 bytes at a time to the wifi shield's buffer