i tried espip/OTA
not OTA but ota
this is case sensitivity
try too check ota server from Your browser (type this address):
http://YOUROTASERVERIP/v1/device/rom/?action=download_rom&version=123.456&filename=user1.bin
if get binary file with some size (>0), server works ok.
this is my default.aspx for windows server - from one of posts from this forum
and index.php for lighttpd + php for openwrt
first and second server works ok
the second webrequest from Your post do not reqest file
for this query default.aspx (as You see) reply with this:
{"\"recommended_rom_version\": \"v0.19\", \"status\": 200, \"productRoms\": [{\"recommended\": 1, \"version\": \"v0.19\", \"life_cycle\": \"beta\"}, {\"recommended\": 1, \"version\": \"v0.18\", \"life_cycle\": \"beta\"}, {\"recommended\": 1, \"version\": \"v0.17\", \"life_cycle\": \"beta\"}]}"
You must carefully read default.aspx,
only request with parameter filename inside GET giving You binary file as answer
and for opposite, parameter is_format_simple inside GET request giving you simple json reply as I wrote above
SDM Energy Meter: https://github.com/reaper7/SDM_Energy_Meter
MLEDScroll (TM1640 led matrix): https://github.com/reaper7/MLEDScroll