I'm using lwIP 1.4.1 and the included httpd web server. In my design, I had one webpage with 12 text boxes that would get submitted using CGI, then populated with the same information using SSI. The information is a time and temperature, for what it's worth. This worked fine, but recently I've increased the number of text boxes to 24 and have run into a problem.
I've increased LWIP_HTTPD_MAX_CGI_PARAMETERS to 32, which is more than I need but for now it's fine. The problem appears when I fill in these text boxes then press the Submit button. Each box is either blank, or contains the same number of characters. Up to a certain number of boxes populated is fine. When more than this number of boxes are populated, httpd will sometimes not return any data to the browser when I hit Submit.
Interestingly, if I reduce the length of the text box "name " in html (which is what gets sent to lwIP to identify the CGI parameter), recompile/reprogram, I'm now able to populate more text boxes without running into this issue. It's only when I "submit"; simply requesting the webpage, even with too many boxes populated, causes no problem.
What parameters could cause this problem? I've tried increasing some of the general lwIP parameters but nothing makes a difference.