Descargar firmware para MicroBT Whatsminer M21

1. Applicable mode 1.1 M21S, M20S, M21,etc; 1.2 High mode can not be supported; 1.3 Teaching video: https://youtu.be/L-gpDzD9YCU 2. New version highlights 2.1 Support Pool TLS safety transportation protocol; 2.2 If the miner firmware is before 2021, it is recommended to upgrade the firmware after SD-card flashing; 2.3 Strengthen the safety of firmware: device will reboot 2 times during upgrading,the version name will be end with"NeedUpgradeAgain" at 1st time，please wait for 2nd reboot, after that it will be changed to target version; 2.4 Fixing other bugs; 2.5 Online upgrading to version earlier than 20210602 is prohibit， suggest to match with tool whatsminertool-8.1.34 ; 2.6 The WhatsMiner API version is V2.0.5;