We reverse engineered the switching protocol for the DNVT and implemented a Raspberry Pi Pico firmware to interface with them. The device uses RS422 transceivers and transformers to send and receive bits in differential manchester encoding. The firmware leverages the Programmable IO modules on the RPi Pico, one for tx and one for rx for each of the 4 phone interfaces.
Files
DNVT_box3rt_top_bom.csv
BOM, JLCPCB
Comma-Separated Values -
1.06 kB -
04/03/2023 at 10:03