Have been using the Roving Networks devices with pretty good success, but have had enough trouble with them that I was spending a lot of ergs working with their support folks (actually Microchip, since they bought RN) until a followup query about four months back got a “no longer supporting Wifly modules, end-of-life” response.
So I decided to try the Global Cache WF2SL, having had good luck with their wifi-relay module. The things work for a while, but after a few days, start having issues with serial communication, and start not accepting TCP connections with increasing frequency until they stop responding at all and have to be power-cycled. Their support suggested it might be a bad piece of hardware, but a second unit is behaving the same way. I have tried to get them to explain their device’s state machine to me, and no-one there seems to know. The use model I have is: 1) connect; 2) write 3 bytes over serial; 3) read 3 bytes over serial; 4) close connection. This can happen several times in a minute.
I suspect they may be doing something stupid vis-a-vis keeping their end of the connection alive after the requestor has dropped its; but they don’t seem to know. I can consider daemonizing a connection agent, and opening the connection and keeping it open, and having my stack talk to that. But would rather not. I’m also not nuts about the fact that the Global Cache radios are 802.11a/b only.
So my question is: can anyone recommend a solid, reliable wifi-to-serial device? Within limits, cost isn’t critical. Even size is negotiable. I am hoping to avoid having to put a SFF computer with a USB-Serial adapter at the serial devices just to get this stable.