A Red Pitaya and Hermes Lite 2.0 I2C ctrl board (Alex retrofit)
Kicad files
I2C control board interfacing
Alexiares/Penelope input/output filter set
with Hermes Lite 2.x & Red Pitaya
It could also be used with a decimal/7 bits binary input for
Hermes lite 1.0
This board is a fork of the DC2PD interface for the Red Pitaya
http://rz1zr.ru/files/Hermes_and_Alex_outputs.pdf
It has
been designed to
Control a simple BCD or decimal filter (J6 output of an Hermes Lite)
In this case, the TCA9555 and the 5 pins “I2C Input” connector are not used
=== Hardware modifications===
A set of darlington (ULN2803) is used to fit the voltage
and current requirement of both lpf and hpf boards.
A pair of jumpers located close to the output connectors
allow to use the “local” 12V power rail if set,
or any external voltage when opened.
For hams using this board with the KF7O’s Hermes Lite V1 (deprecated dev.), two connectors
have been added to directly control the drivers in decimal mode,
thus to control a Penelope, Alexiares or an Alex SV1AL softrock based
“Big Mobo” filter set ( or any filter
board using negative logic band switching)
Please note that the antenna and attenuator commands need a separate
board if an Alex lpf/hpf filter set is already used (Pavel’s firmware).
An antenna switching board project could be downloaded and/or forked from
https://github.com/F6ITU/Alexiares_Coax_Out
(attenuators are integrated on the HPF filter board, under design)
When using AlexI2C, Alexandrie control board, the original I2S interface
https://github.com/F6ITU/Alexandrie
should NOT be used (it seems obvious, but who knows…)
AlexI2C acts as an “almost complete” substitute of the original board and is
dedicated to people who don’t want to use Alexiares’s I2S protocol.
3D image of the board are stored on this repo
Alexi2C dwn.jpg
Alexi2C up.jpg
Board’s dimensions are oversized to fit the 5x10 and 10x10cm
size of all board of the Hermes project under Kicad:
AlexI2C
Alexandrie
Alexiares_Coax_Out
Alexiares_HPF
Alexiares_LPF
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