GOOZEEZOO V1.5.2 MMDVM Duplex Dual Hotspot Hat with 0.96" OLED Supports DMR Slot1+Slot2/P25/D-Star/YSF/NXDN, VHF&UHF Coverage, Pre-flashed Firmware, Compatible with Raspberry Pi

Extensive Compatibility: Supports DMR, P25, D-Star and System Fusion. Built with high-performance 32-bit ARM processor and maximum 10mW RF transmit power; every unit undergoes full functional testing. Compatible with Raspberry Pi series: Pi 1, 2/2B, 3/3B/3B+, 4/4B, Pi Zero and Pi Zero 2W

Easy Assembly & Operation: Pre-flashed firmware supports convenient software-based upgrades. Onboard LEDs clearly display Tx, Rx, PTT and operating mode status. Pi-Star supports flexible mode switching between Duplex Mode and Simplex Mode

Frequency Range: UHF:  433–900MHz; VHF: 144–146MHz.
Main amateur radio bands: 144–148MHz, 219–225MHz, 420–475MHz, 842–950MHz. Optimal working amateur band: 430–440 MHz.
NOTE: TX=0, RX=0. To keep the OLED screen permanently lit: In Pi-Star settings, select OLED Type 3 for display type and set Port to modem

Configuration Guidance: Adjust the modem type; all models ending with GPIO are supported.
Radio/Modem Type: STM32-DVM/MMDVM_HS-Raspberry Pi Hat(GPIO)

Navigate to MMDVM Host under the Expert menu and locate the OLED settings. Set LogoScreensaver to "1" to maintain constant screen illumination; the display will turn blank automatically during idle status without this setting

New Firmware Upgrade: Access path: Pi-Star → Expert → SSH Access
Account: pi-star | Password: raspberry
No jumper adjustment required;  (run in the Pi star terminal): sudo pistar-mmdvmhshatflash hs_dual_hat (if this command doesn't work, please try this command: mmdvm.club/index.php/wpsd .html)