4d systems display - do I need the USB to serial interface?

Hi,

I am considering this display for a project and wondering if I need the USB to Serial adapter or not. http://www.4dsystems.com.au/product/3/20/Arduino_Display_Modules_and_Shields/uLCD_32W_PTU_AR/

Here is a quote from Sparkfun regarding it:

Like the other displays from 4D Systems you will need a USB Serial adapter to program this module. Unfortunately, our FTDI Basic Breakout won't work. Check the related items below for 4D Systems' FT232RQ breakout.

If it is needed I wonder why it is not included in the package from 4d systems. I don't mind the price, the problem is that the breakout will not be available until late next month. https://www.sparkfun.com/products/11814

So do I need it? Or is it only for some special cases?

Best, Sammi

Unfortunately, our FTDI Basic Breakout won't work. Check the related items below for 4D Systems' FT232RQ breakout.

While their support information appears to be excellent, I think this comment is specious.

I note their slightly confusing description in the pinout of their special adaptor of a pin as "RST" or "reset". A problem with many of the "counterfeit" USB to TTL serial adaptors is that they actually bring out the reset pin of the CP2102 which is absolutely useless.

I suspect that the 4D Systems adapters actually incorporate the differentiating capacitor which generates the reset pulse for programming from the RTS or DTR line, whereas in Arduinos, this capacitor is incorporated on the main board for compatibility with standard FTDI (0r CP2102 or PL2332HX) adaptors.

If you have the display module on hand (or an actual schematic), you could confirm this. Oh, never mind - I just did! You can use any standard (and cheap) FTDI or equivalent adaptor simply by making the appropriate connections and connecting the Reset line on the 4D interface board to RTS on the adaptor via a 0.1µF capacitor.

You cant use the FTDI cables as they do not break out the DTR which is used for reset on the 4D products, but you could use the FTDI basic board as it does break out the DTR line. you would need to do the series cap etc stuff yourself externally though, so its easier just to buy the correct programmer.

4D provide warnings about using anything other than what they supply not so you have to buy their programmers, but so you don't brick the processor. Yes, it can happen, and yes it will void your warranty, as they warn about in their datasheets.

They sell both the SK (Starter Kits) and the displays by themselves or in an Arduino (-AR) kit for a reason. If you already have a programming cable then you dont need to purchase another one, so you just buy the display or the Arduino kit etc. If you dont have anything, then it makes sense to buy the SK which includes everything you need.

Its all written in their datasheets.

WanaGo

Paul__B: While their support information appears to be excellent, I think this comment is specious.

I note their slightly confusing description in the pinout of their special adaptor of a pin as "RST" or "reset". A problem with many of the "counterfeit" USB to TTL serial adaptors is that they actually bring out the reset pin of the CP2102 which is absolutely useless.

I suspect that the 4D Systems adapters actually incorporate the differentiating capacitor which generates the reset pulse for programming from the RTS or DTR line, whereas in Arduinos, this capacitor is incorporated on the main board for compatibility with standard FTDI (0r CP2102 or PL2332HX) adaptors.

If you have the display module on hand (or an actual schematic), you could confirm this. Oh, never mind - I just did! You can use any standard (and cheap) FTDI or equivalent adaptor simply by making the appropriate connections and connecting the Reset line on the 4D interface board to RTS on the adaptor via a 0.1µF capacitor.

Very close. Luckily one does not need the 0.1µF capacitor. Simply linking/connecting the DTR (data terminal reset) line to the RST/"reset" terminal on the 4D systems touchscreen will do the trick.

samueljonasson: If it is needed I wonder why it is not included in the package from 4d systems. I don't mind the price, the problem is that the breakout will not be available until late next month. https://www.sparkfun.com/products/11814

So do I need it? Or is it only for some special cases?

It's not included in the package because you probably only need one, no matter how many displays you buy. I have one and it's the most useful FTDI that I have. I glued another header on the back which is wired for the 'normal' FTDI pinout and I use that to interface to lots of things, including all the Arduinos without USB sockets.