Raspberry Install MicroPython for Pico
In addition to installing Thonny on the computer, we also need to install the MicroPython firmware on the Pico itself.The MicroPython firmware download link is preloaded inside Pico, so we can directly use this link to enter the download interface.
First, hold down the “BOOTSEL" button on Pico; then, while still holding it down, connect Pico to a computer using a USB cable.
At this point, a drive called RPI-RP2 should show up as a removable device on your computer. Navigate to it to find this file: INDEX.HTM.
Open INDEX.HTM to be taken to the download page. Drop down and click on the MicroPython tab where you can find information about Pico and MicroPython. Click on the “Download UF2.file" button in this tab to download the MicroPython firmware.
Finally, drag the downloaded MicroPython firmware into the RPI-RP2 directory to complete the firmware installation.