Portsdown - where do I begin?
Hopefully you've reached this page because you've read the system overview and want to know more - if not, we suggest you do spend 5 minutes reading the system overview.
OK - now you've read that, you want to get started!
The next thing is really to read the hardware overview - sorry but there's load of useful information in there, such as where to buy the various bits that you need to send pictures across the shack.
Once you've read (or decided not to read!) the Hardware overview, you can see there's not much to it!
So here's the shopping list - a full list of suppliers with links to their website is available on the Hardware overview page.
Shopping list
Raspberry Pi
Ideally you will buy a version 3, but if you have a version 2 or even a Model B lying in the cupboard, give it a try. Because, believe it or not, that's all you need to send pictures across the shack! But to do this you will have to read another section of the user manual and follow some instructions!
So go and have a look at the initial set up guide - follow those instructions and using QPSKRF Ugly mode, you will be able to send pictures across the shack but you really need to read this section on Ugly mode as there's several things it cannot do.
Important note - the Portsdown transmitter has been designed to "work out of the box":
- You do not need to do anything other than follow the initial set up guide
- Do not connect a mouse, keyboard or monitor to the Rpi
- Do not load any device drivers
- Do not tinker with Linux commands
If you do, we don't have time to support you and will just advise you to reformat your SD card and start again!
However, if you do not want to always have a computer connected, you'll need to buy the touchscreen. But make sure you buy the right one from Amazon - other ones that look the same but they may not work and may even use pins on the Rpi GPIO that we already use for other connections.
Once you've bought the screen, you'll need to read initial set up again to learn how to configure it and make the Rpi boot straight to it so you never have to use the PC again.
By now, you're probably bored of the test sequences and bouncing balls so you want to add a camera input. You can have 2 types of camera:
The Raspberry camera
This produces very high quality images but is just the camera.
Easycap USB dongle
This has a yellow video phono connector on it and will enable you to connect you mixing desk, old camcorder or even your old VHS tape machine!
Guess what, once you've bought the camera or USB dongle, you'll need to read initial set up again to learn how to configure them and send live pictures from your Raspberry Pi.
Audio input
Presumably you want people to hear what you are saying so will also need a USB audio dongle - there's loads on ebay :-)
Modulator Filter PCB
So up until now, you've been sending pictures across the shack using Ugly mode (Serious note - Please don't connect it to an aerial unless you want a visit from Ofcom!).
Right now, that's all you can do because the modulator / filter board is not quite ready. Once it is (and you'll be able to buy it from the BATC shop) this will enable you to get on air properly with DATV on 146, 437 and 23cms.
ADF4351 Local Oscillator
As well as the Modulator Filter board you will need an ADF4351 chip to use as your local oscillator. Luckily, these are available from ebay ready assembled on a small PCB with an SMA connector so it really is "plug and play". These are modules are available now and the Portsdown transmitter will definitely use one, so why not buy one and you'll be ready when the Modulator board is available.
GPIO extender board
In order to get at all 13 signals we need to and from the Rpi, we need to use a GPIO breakout board - these are cheap but the card must break out all 40 pins of the GPIO, and have another connector on top for the LCD display. The recommended unit is listed in the hardware overview
Filters and drivers
That's all there is to the Portsdown transmitter - 6 simple parts, but of course, just like any other DATV transmitter, you will need filters and driver amplifiers - there's lot of designs around and anything you have built or bought for Digilite or DTX1 will work well with the Portsdown transmitter.
Take a look in the filters section of the wiki.
Where to buy the components?
Now you really do need to read the hardware overview as at the bottom of that page is a list of suppliers with links to their website where you can buy all the components needed.