View Full Version : FT232R to program both Prop and VNC2?

04-04-2012, 01:24 PM
Thinking about a board with both a Propeller and VNC2 on it...

I think most of us use the FT232R to program the Propeller. But, it's also what is used to program and debug the VNC2...

Just took a look at the idea of using a single FT232R chip for both...
I think it's doable. The Propeller is a simpler interface actually.

One thing that concerns me is that the VNC2 programmer has DTR connected to DSR and CTS connected to RTS.
I'm not completely sure what affect, if any, that will have on the Prop Tool...

I guess another question is: Can I use the new FT231X chip for this?

04-04-2012, 08:04 PM
I don't see why you couldn't use the FT231X to do it. It would be an easy question for their tech support to answer, why not email them?

I think the debug port is mostly used for the initial configuration. It might be possible to use the prop to redirect serial to/from the debug port of the vnc2

The other possibility is a FT2232 with dual ports, one for the prop and one for the VNC2

I would love to have the time to get to grips with the toolchain of the VNC2. There are good examples for connecting logitech webcams etc. I'm sure keyboards and joysticks would be easy too. There's not much price difference between the VNC2 and the FT232R nowadays, but the VNC2 gives us so much more. The Vinco board is a good way to get going quickly.

Did you see they set up a new Android section on the FTDI site too

04-04-2012, 10:00 PM
Why don't you use the VNC chip to do both RS232 and USB host? It has 2 ports and a firmware available to do that.

04-04-2012, 10:17 PM
pedward, then how to program and debug the VNC2?
Besides, I want to use both ports, one for keyboard, one for mouse...

04-04-2012, 10:37 PM
Typically you will program the VNC once with the proper firmware, then just use it. If you intend for the Prop to be a dev environment for the VNC, then I can see the need for a PropPlug or the like.

I was thinking of doing a PropKey with the VNC chip, and in that case I *would* use it for RS232 and USB host.

04-04-2012, 11:10 PM
Maybe with VNC1...

VNC2 has a lot of different options and an OK IDE...
I wouldn't want to tie myself down...
Plus, there are a lot of GPIO pins that you may want to use for different things...

Besides that, programming the VNC2 is kinda interesting, and if you get that for free, I like the idea...

Tubular, I did just contact FTDI as you suggested and they say the new chips can be used.
So, I may give FX230X or FX231X a shot on this board...

04-04-2012, 11:44 PM
BTW: I just asked FTDI another question... Has anybody programmed a VNC2 with FT231X?
They said: Not yet, but we don't foresee any problems...

04-05-2012, 12:19 AM
I have a UMFT230XA and a Vinco and a long weekend, so guess I could give it a try.

The other question is what signals (RTS, DTR etc) are used by the VNC2 IDE to initiate the programming? If the IDE toggles DTR, or both DTR and RTS, then using a prop plug (with changed wiring to emulate the FTDI header) is a chance.

It will also be interesting how much data is needed to config the VNC2, and whether the protocol is open/available. Perhaps it will be possible for the prop to send it an image from an SD card, or if its small enough, embed the configuration image in DAT code. This is the same idea we had with making it easy to apply slave micros (PIC/AVR TWI/Freescale/Silabs) without having to install their IDE to get things talking.

Time for you to get back on the phone to them, make them earn their keep :)

04-05-2012, 12:37 PM
ftdi application note 138 (http://www.ftdichip.com/Support/Documents/AppNotes/AN_138_Vinculum-II_Debug_Interface_Description.pdf) describes the debug programming interface. It is based on a FT232R, but needs the Cbus pins broken out, and some handshaking lookbacks.

Definitely looks possible. Might need a little external logic to switch target from vnc2 to prop based on cbus states.

Not sure whether the Cbus functions would translate correctly to a FT230X or FT231X.

04-17-2012, 06:56 PM
Just got some FT231X chips... Here's what they look like relative to FT232R: