Imagine that reality really did exist. What will you build today?
This is a project to consider when you have a Asterisk PBX / RF Gateway where you can use the Text-to-Speech (TTS) capabilities to deliver S.A.M.E. Alert message notification. Finally getting some updates in here for the Si4707 Weather Radio project. Take a look at Si4707 Hookup Guide via sparkfun additional information to follow shortly.
Make your own transceiver
Dorji Applied Technology manufactures the DRA818U and DRA818V transceiver modules. Here’s what they have to say about these modules:
DRA818U is based on RFIC RDA1846. It has the same pin sequence and dimensions as DRA808M module so users can replace the DRA808M with it directly. Comparing to DRA808M module, DRA818U are added with CDCSS function except CTCSS and AT command-SETFILTER which users can use it to turn on/off Pre-emphasis/De-emphasis function, High pass filter and low pass filter.It provides users more flexibility in process audio signal for different applications.
DRA818V is the VHF band version of DRA818U module. It works at 134MHz~174MHz which covers the common HAM radio frequencies such as 144MHz, 145MHZ, 146MHz, 154MHz, 157MHz,160MHz, etc. It has the same function and pin layout as DRA818U module except the frequency so users can easily exchange the two modules according to the requirement and do not need to make second development in hardware.
Project information can be found at: PDØAC – Hamgear and the finished project with schematic and sample Arduino code at: Building blocks for DIY VHF / UHF FM transceiver. Module on carrier boards are available: