band select output from HL2

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Patrick Anglum

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Nov 27, 2023, 1:32:20 AM11/27/23
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I need output signal(s) from the HL2 indicating what band I am currently using.
I need this signal(s) to interface to multiband low pass filter.

I have read comments about an analog signal in which the voltage indicates what band is being used.  I also read in the Thetis manual about OC (open collector) outputs being available, but I don't see anything on the HL2 schematic that would support such operation.

Does anyone know if either of these two options are available?
If not, what are people using to indicate what band is in use?
Thx,

Pat
N6XTM

Mike Lewis

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Nov 27, 2023, 1:45:43 AM11/27/23
to Patrick Anglum, Hermes-Lite

Look in the forum for IOBoard topics, many of them concern programming it for serial, voltage level and parallel IO (like BCD pattern) IO.  Also look for threads controlling amplifier band changes.  Lots of discussion and solutions to be found.

 

The Thetis OC outputs when used on the HL2 are sent as I2C commands and control the N2ADR board if you have it, or if you have your own board in the filter board connected, it can listen to the I2C bus in its place.

 

The voltage outputs can be for a fan (PWM) or analog level. Voltages should be in the HL2 WIKI.  

 

The IO Board can add new voltage, serial and IO outputs and must be programmed.  It can match any standard such as Xiegu, Icom, or FT817 for starters, but does require you write a small bit of code or use one of the examples that exist from users and the IOBoard GitHub repo example firmware.

 

If you have a specific details (voltage, bit patterns, will you have a CPU or logic at the filter end?) that would be easier to answer, otherwise the generic answer is ‘it depends’ per the above.

 

  • Mike

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G4ZAL

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Nov 27, 2023, 5:47:09 PM11/27/23
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I currently use the HL2's actual frequency, sent over serial by using this to output the data 
Homebrewed my own serial board (it's a bit like constantly reading the VFO of a traditional rig)

The HL2 serial output is fed into an Arduino Nano and then converted into whatever format I want.
Currently using it to generate BCD data to send to my PA and simultaneously retransmit the same serial data over RF via 433MHz modules to my remote tuned antenna system which also has an Arduino Nano reading in the 433MHz module data and switching tuning relays as required per band (all powered by homebrewed 12v bias-tee over coax).
This method is software independant and as the HL2 is controlling things it works well for remote operation (either at home or over the internet).
There is plenty of Arduino code floating around to produce almost any output you want (HR50, Xiegu, icom, BCD etc)

Previously tried reading the N2ADR board data over i2c, but this does not have band data for 60, 17 or 12 metres so no good for my linear and antenna system.

The new Pico IO board may well be able to do the same, but for now, I have all I need.

Nigel
G4ZAL

Mike Lewis

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Nov 27, 2023, 8:25:32 PM11/27/23
to G4ZAL, Hermes-Lite

The serial output from the HL2 FPGA is the HL2 TX frequency, not the SDR app dial frequency (or group of virtual RX and the TX).  So the HL2 only approach is usually sufficient for HF amps, not for VHF+ applications. The new IO board addresses that requirement well.

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bai5CD241G1JF

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Nov 29, 2023, 2:16:24 PM11/29/23
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Okay,  I think I'll go with the analog voltage output.
I think the signal can be found on DB1 pin 4.
But where is the setup in the gui to change the fan output to a variable voltage indicating the band in use?

bai5CD241G1JF

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Nov 29, 2023, 2:16:25 PM11/29/23
to Hermes-Lite
Thanks to all for the help.
I'm going with the analog voltage out of the fan connector.
Where do I configure this alternate operation in Thetis?

On Monday, November 27, 2023 at 5:25:32 PM UTC-8 K7MDL wrote:
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