This is the config file, test report and update tool. Please follow the steps below to update the config file on i-series 15.6.
NOTE: This will not work on the 10" Android I-Series, it has a different controller.

1. rename the config file to update.xcfg
2. save update.xcfg and MxtUpdateFW_signed_aligned.apk in a microSD card.
3. insert the card to i-series 21.5
4. install MxtUpdateFW_signed_aligned.apk and run it
5. after updating the config file, please check the result on the screen if the checksum is 0x5168F0

NOTE: this config file can support 10 touches without gloves. However, 2 kinds of the gloves can support only 2 touches, because the performance becomes worse if more than 2 touches. The other gloves can support 5 touches. The details are in the test report.

