Just as power via USB! 
Duplex MMDVM Hotspot Board + OLED + on-board Antenna + Case Kit Support P25 DMR YSF For Raspberry Pi
 

Features:
-High performance 32-bit ARM processor
-Supports DMR, P-25, D-Star and System Fusion
-Fully tested
-Onboard LED to show status (TX, RX, PTT, Mode)
-SMA antenna connector, antenna included
-Mounts cleanly on all current Raspberry Pi's including the Pi Zero
 
WIDELY COMPATIBLE: Supports DMR, P-25, D-Star and System Fusion
WORK with RASBERRY Pi: Mounts cleanly on current Raspberry Pi including the Pi Zero
Mode: Support both Duplex mode and Simplex mode
Differencs in Duplex and Simplex:in Duplex mode,have 2 time slots, and Tx and Rx can do at the same time
Radio Frequency : in duplex mode,support uhf 430-440MHZ, in simplex mode support both uhf 430-440MHz and vhf 140-150MHz
Best adjusted: TX =0, RX=0，need no offset.
Modem select: STM32-DVM/MMDVM_HS-Raspberry pi Hat(GPIO)
Aluminum shell:High RF performace
Antenna: on board two antennas