1. Why my IR collision sensor not work properly, the barrier indicated light keep stays on while there's no barrier in front?
- check if the barrier indicated light keep on while there's no obstacle in front. If it is, please check if the IR sensors are getting too close or deform, try to seperate or straighten them slightly and check if the barrier indicated light still keep on;
- try using a 2.5mm cross screwdriver to adjust the sensitivity regulator clockwise (Reduced sensitivity);
- if the above method doesn't work, try change the abnormal IR sensor to another one beside, to figure out the problem is from IR sensor or connecting port on mainboard. If the abnormal IR sensor still not good after changing the connecting port, it means the problem may occurred on the IR sensor, otherwise it may occured on the connecting port on mainboard;
2. Why the mBot Mega cannot be controlled by Makeblock app, which was recognized as "Ultimate 2.0"？
Some products are with this problem due to the old firmware version,
In this case, you may need to use mBlock5 software, select device "mBot Mega" and update the "Online Firmware" to realize correct app control;
If you want to use the origin functions of mBot mega(Line following/avoid obstacles), you may need to update the "Factory Firmware".
Please refer to https://support.makeblock.com/hc/en-us/articles/1500013010242-Updating-the-Firmware-of-mBot-Mega for detail information.