The backlight draws the most power from this design so I will optionally allow 5V to be supplied externally from a supply that shares a common ground with the Arduino itself. 3.3V will be used to set the reference for the LCD side of the regulator.
5V will be used to power the backlight driver as well as set the reference level for the Arduino side of the level converter. We need both 5V and 3.3V inputs for this design. The NCP5007 will be configured to supply a constant 20mA through the backlight circuit and we will use a PWM signal on the ENABLE pin to vary the brightness. Just like before, I will use the OnSemi NCP5007 constant current backlight driver to do the heavy lifting here.
Like the 2730 before it, the 6300 backlight consists of 4 white LEDs in series requiring around 13V to power them. The connector on the LCD FPC cable The backlight This helps to identify where pin 1 is located because the big “1″ silkscreen’d on to the FPC is in the wrong place. If you look closely you can see where the ground pins connect directly into the ‘ground pour’ inside the ribbon cable. Here’s a photograph of the LCD side of the connector. The pinout for the connector is shown here: Here are some direct links to the ones that I know of: It is easy to obtain them either direct from JST’s online shop or in small quantities from online sources. It is made by JST and the part number is 24R-JANK-GSAN-TF. An eagle-eyed reader has identified the manufacturer and the part number. The connector is the same 24-pin board-to-board connector used in the Nokia 2730. The connector is readily available from online sources.You would be forgiven for not noticing the difference between 16M and 262K colours though. It claims to support 16M colours (24 bit).It’s readily available (on ebay) and costs very little.I picked the Nokia 6300 for this project for the following reasons: Well, since that project I noticed that a great many of Nokia’s QVGA displays seem to vary only slightly in their pinouts and as such the likelihood of them using the same controller would be high. The 6300 panel with protective film attached
Given that the previous article showed how to reverse engineer the Nokia 2730 LCD you could have been forgiven for assuming that this was the one I’d use. Perhaps the first surprise of this article is my choice of LCD. So now you know the endgame, let’s take the time to explain it all in detail.
Doing it like this opens up the possibility of full colour bitmap graphics at a respectable refresh speed. There is no faster way to transfer data out of the Arduino Mega to a peripheral. The graphics library will use the external memory interface built in to the Arduino Mega to transfer data to the LCD in a single assembly instruction. The real innovation will be in the graphics library that I present in part two of this article set. This article brings together the knowledge we have gained in the previous two articles and puts it to use by creating a project that will allow a Nokia QVGA 24-bit colour TFT LCD to be indirectly connected to an Arduino Mega via a level converter, all on one small 50mm PCB.Īll quite straightforward so far. In two of my previous articles I showed you how to reverse engineer the Nokia 2730 LCD for connecting to a device with 3.3V I/O’s and then I showed you how to build a 16-channel level converter for connecting devices together that have differing I/O level requirements.