• TRADFRI wireless dimmer IKEA ICTC-G-1
• Firmware build date 20170612
• Firmware version 1.2.248

{“installed_version”:304383346,“latest_version”:587367985,“state”:“available”},“update_available”:true}'

• It sends only action brightness_move_up brightness_move_down messages, so enabling Simulated brightness in Zigbee2MQTT is needed
• Additionally it detects very fast movenents and translate it to on/off actions, sending brightness: 0 or ''brightness: 255' messages
• When brightness is 0 or 255 it floods with message with the same brightness (probably to guarantee that every bulb receives information ?)

After fw update:

OTA: Got request '{"fieldControl":1,"manufacturerCode":4476,"imageType":4546,"fileVersion":587367985}'
OTA: Is new image available for '0x000b57fffe928192' (TRADFRI wireless dimmer), current '{"fieldControl":1,"manufacturerCode":4476,"imageType":4546,"fileVersion":587367985}'
TradfriOTA: call getImageMeta for TRADFRI wireless dimmer
OTA: Is new image available for '0x000b57fffe928192' (TRADFRI wireless dimmer), latest meta '{"fileVersion":587367985,"url":"http://fw.ota.homesmart.ikea.net/global/GW1.0/01.21.031/bin/159701-2.1-TRADFRI-wireless-dimmer-2.3.028.ota.ota.signed"}'
OTA: Update available for '0x000b57fffe928192' (TRADFRI wireless dimmer): NO
No update available for 'lewy_ikea_galka'