Hi all,
I was wondering if anyone has developed a slick PTT solution for the DATV Express board? I'm looking to use the PTT function to switch Tx/Rx relays and trigger PAs. I'm guessing that opto-couplers are needed and would be interested in members solutions. No point re-inventing the wheel...hi.
73
Malcolm
G0UHY
DATV Express PTT options
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This forum is run by the BATC (British Amateur Television Club), it is service made freely available to all interested parties, please do not abuse this privilege.
Thank you
Re: DATV Express PTT options
Hello Malcolm,
Have you considered the cheap Chinese relay boards you can buy on eBay?
They are opto isolated and are what I have used.
- Charles
Have you considered the cheap Chinese relay boards you can buy on eBay?
They are opto isolated and are what I have used.
- Charles
Re: DATV Express PTT options
Hi Charles,
sounds like a good cheap option. Just had a look on eBay and there are loads of them!!! Which one have you used (12V,5V and how many relays). Any chance of a diagram of how you have interfaced it to the Express Board?
73
Malcolm
PS When will the S2 software for Windows be available?
sounds like a good cheap option. Just had a look on eBay and there are loads of them!!! Which one have you used (12V,5V and how many relays). Any chance of a diagram of how you have interfaced it to the Express Board?
73
Malcolm
PS When will the S2 software for Windows be available?
Re: DATV Express PTT options
Hi Malcolm
I used the 5v relays (to simplify the PSU). I bought the 8 relay boards (not all are used).
I didn't actually connect it directly to my Express board but instead I used another
(Cheap Chinese again) FPGA board but that was only because I had not written the PTT code
for Express at the time. The Electrical interface is the same.
I just connected the system ground and then the outputs of the FPGA directly to the
Opto isolator interface on the Chinese board. (Hence I have no circuit).
If you can wait I will ask Ken to put something in the manual as you are not the first person
to ask this question.
As for the S2 code, it is being tested at the moment, Dave G8GKQ found a fault in it when
operating at 333K. That has since been fixed. At the moment the latest is in my Dropbox
https://www.dropbox.com/s/noypydy5t45cg ... 0.zip?dl=0
If no further faults are found it will be posted on the Express website.
- Charles
As an after thought if you want to use the same 12v supply to drive the relay board as you use
to drive Express you might consider a 12v board instead.
I used the 5v relays (to simplify the PSU). I bought the 8 relay boards (not all are used).
I didn't actually connect it directly to my Express board but instead I used another
(Cheap Chinese again) FPGA board but that was only because I had not written the PTT code
for Express at the time. The Electrical interface is the same.
I just connected the system ground and then the outputs of the FPGA directly to the
Opto isolator interface on the Chinese board. (Hence I have no circuit).
If you can wait I will ask Ken to put something in the manual as you are not the first person
to ask this question.
As for the S2 code, it is being tested at the moment, Dave G8GKQ found a fault in it when
operating at 333K. That has since been fixed. At the moment the latest is in my Dropbox
https://www.dropbox.com/s/noypydy5t45cg ... 0.zip?dl=0
If no further faults are found it will be posted on the Express website.
- Charles
As an after thought if you want to use the same 12v supply to drive the relay board as you use
to drive Express you might consider a 12v board instead.
Re: DATV Express PTT options
Hi Charles,
thanks for the prompt reply and information. Won't get around to building anything at the moment due to having a holiday planned. I thought that a few people would be wanting to do the same thing so if Ken could document it that would be great!!
73
Malcolm
G0UHY
thanks for the prompt reply and information. Won't get around to building anything at the moment due to having a holiday planned. I thought that a few people would be wanting to do the same thing so if Ken could document it that would be great!!
73
Malcolm
G0UHY
Re: DATV Express PTT options
Hi Malcolm
I use an opto isolator / relay board similar to ebay part number 291566724157 directly on to the DATVexpress I/O pins.
The pinout is detailed in the manual page 32 but could be misleading as it calls them PTT ports and they are not - the pin is high on both tx and rx when selected. (note it is J6 and not J4 which had the original PTT line and you will need to add a header).
I use a port per band, saved in a config file along with other settings for the band, and put the PTT line out on pin3 through the relay bank to get PTT band switching. You can get as many output configs as you need as multiple pins can be ticked at once and saved in the config.
Hope this helps.
Noel - G8GTZ
I use an opto isolator / relay board similar to ebay part number 291566724157 directly on to the DATVexpress I/O pins.
The pinout is detailed in the manual page 32 but could be misleading as it calls them PTT ports and they are not - the pin is high on both tx and rx when selected. (note it is J6 and not J4 which had the original PTT line and you will need to add a header).
I use a port per band, saved in a config file along with other settings for the band, and put the PTT line out on pin3 through the relay bank to get PTT band switching. You can get as many output configs as you need as multiple pins can be ticked at once and saved in the config.
Hope this helps.
Noel - G8GTZ
Re: DATV Express PTT options
Hi Noel,
thanks for the info. As you say the pin outs are quite confusing which is one of the reasons for the post. I thought someone must have come up with a solution. I think Charles is going to ask Ken to add the info to the draft document as he has been asked by a few people about it.
Relay board ordered and on a slow boat from China ...hi.
73
Malcolm
G0UHY
thanks for the info. As you say the pin outs are quite confusing which is one of the reasons for the post. I thought someone must have come up with a solution. I think Charles is going to ask Ken to add the info to the draft document as he has been asked by a few people about it.
Relay board ordered and on a slow boat from China ...hi.
73
Malcolm
G0UHY