Firmware Version 1.4 (December 5, 2025)
Minor update that sets altitude offset to zero when exiting sleep mode.
SonoAlti_4V_Firmware_1_4.uf2

Flash Revealer: SonoAlti_4V_16MB_Flash_Revealer.uf2
Flash Eraser: SonoAlti_4V_Flash_Eraser.uf2
SonoAlti 4V Sounds: SonoAlti_4V_Sounds.zip

SonoAlti 4V Hardware Diagnostics: SonoAlti_4V_Hardware_Diagnostic_Test.uf2