The Frequency Reader is a no-frills device that allows you to have a frequency readout far away from the radio. It is based on Atmel ATmega168 (actually ATmega48/88/168/328) and HD44780 LCD display (16 chars on 2 lines).
It started as a transition device between the external keypad and the full-featured remote control, that was used as the base to develop and test the display code. But apparently a simple remote display can be useful for some operators or use cases, so it is documented and published on these pages for everyone to try it out.
There are two versions, both using the same circuit.
The first version shows frequency and mode readout. For FT-817 it can be configured to show signal strength and few other info. The main use for this display is when your RTX display is out of reach, such as in a car installation. See a preview video on YouTube. Text of the lower line on the display can be customized, contact me for info. This is a not-supported "product" since there is little interest, so documentation is very scarce. There are also two versions with same functions, based on ATtiny2313 using the same hardware of the keypad, and based on ATmegaX using the same hardware of the I.F.R.
The second version has been developed following the feedback of microwavers that use FT817 as the I.F. for their transverters. This firmware does some math and shows the transverter output frequency on the upper line. Frequencies shown are in Hz. With a couple of buttons it allows reprogramming the L.O. value and supports up to 9 local oscillator values. L.O. can be set between 0 Hz and 214 GHz with 100 Hz resolution. An early version of this accessory was documented with a video on YouTube, and another video too.
Both versions of the Frequency Reader work on FT-817, 857 and 897.
The circuit senses when the radio is switched off, displays a "Comm error" warning and checks every 5 seconds if there is valid VFO data available on the CAT line.