Features: 1. Hotspot Board Kit P25 for Pi-star MMDVM Power Bank 2. Only for Mini Duplex MMDVM board 3. Set up Pi-star software and raspberry hardware (rpi 0-3) New pi4b needs to remove Right Socket 4. Pi-star general configuration of MMDVM_DUPLEX 5. Set controller mode: duplex repeater or simple Description: 1. Radio frequency: Freq: 144-148, 219-225, (main frequency band) 420-475, 842-950 2. Duplex mode: Example: RX: 438.000000 TX: 433.000000 3. Duplex mode: Example: RX: 145.000000 TX: 433.000000 4. Simple mode: Example: RX: 438.000000 TX: 438.000000 5. Radio/Modem Type: STM32-DVM/MMDVM_HS- Hat(GPIO) or any other (GPIO board) 6. : (not needed now, some old boards need to be set) 7. AdminExpertEdit MMDVMHOSTRXOFFSET=0 TXOFFSET=0 (default value in pistar) 8. (Update: 2019/2 new 3225 TCXO so offset is 0) 9. Update new firmware: (pi-star / Expert / ssh access / user : pi-star pass: raspberry) 10. sudo pistar-mmdvmhshatflash hs_dual_hat 11. The default bit error rate is less than 5%, and the default offset is 0. If the bit error rate is 5%, as long as the signal can be received, it can be corrected through offset. Note: Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Will Not Affect The Use size: about 65 x 31 x 15mm Material: Aluminum PCB colour: As Shown Package Contents: 1 x Hotspot Board Kit (With Case And Screen) 2 x Pin Header Socket 1 x Oled Box Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.