The tft driver (comprising tft.py, TFT_io.py and touch.py) was developed by Robert Hammelrath (robert-hh on Github, roberthh on the MicroPython forum). These notes aim to augment his documentation with additional hardware details. Driver sites:
TFT driver
XPT2046 driver

The easiest way to acquire these displays is to search eBay for SSD1963.

Minimal connections for TFT display

These notes are intended for users not intending to use Robert Hammelrath's excellent PCB, which has features including the ability to power down the display to conserve power when not in use.

Most 4.3 inch and 5 inch displays have a 40 way 0.1 inch connector with the following pinout. Pins are usually marked on the PCB silkscreen. Pins marked - are defined as no connect. Signals in parentheses are not required by the driver and are no-connect. Most 7 inch displays use a different connector. Note that the 5 inch 800*480 display is not currently supported by the TFT driver.

The table below is laid out looking at the underside of the display with the plug to the left and most of the PCB to the right. L and R denote the left and right TFT connector pins when viewed this way. Check your own display to ensure it conforms to this pinout!

Signal	Pyboard	L	R	Pyboard	Signal
-		20	40		-
LED-A	Y3 [1]	19	39		-
V-LED	Note [2]	18	38		(SD_CS)
REST	Y9	17	37		(SD_DIN)
(FCS)[3]		16	36		(SD_CLK)
CS	Gnd	15	35		(SD_DO)
(DB15)		14	34	Y1	T_IRQ
(DB14)		13	33	Y2	T_DO
(DB13)		12	32		-
(DB12)		11	31	X11	T_DIN
(DB11)		10	30	Gnd	T_CS
(DB10)		9	29	X12	T_CLK
(DB9)		8	28	X8	DB7
(DB8)		7	27	X7	DB6
Rd	Y10	6	26	X6	DB5
Wr	Y11	5	25	X5	DB4
Rs	Y12	4	24	X4	DB3
-		3	23	X3	DB2
3.3V	3.3V	2	22	X2	DB1
Gnd	Gnd	1	21	X1	DB0

Notes:
[1] Pin 19 controls backlight brightness. The TFT driver supports brightness control using PWM at 500Hz. Not all panels allow PWM in which case it would normally be wired to 3.3V. Consult panel manual.
[2] Backlight power source. Some displays show no connection on pin 18. Others require 3.3V or more: consult the panel manual for the power requirements.
[3] This is a chip select for an onboard 2MB Flash chip. It is unused by the driver and the chip is not fitted to all display models.

The TFT driver tft.py uses pin Y3 and timer 4 for backlight brightness control. Pin 19 can be linked to 3.3V if full brightness is always required. It also uses pin Y4 for power control: with suitable hardware this enables power to be conserved by powering the display down when not in use. If the display is powered down it requires re-initialisation by calling tft.tft_init(). The touch panel requires no initialisation.

Signal descriptions: Signals T_* are the touch panel controller chip connections.
Signals (SD_*) are for the onboard SD card which is unused.
DB0-15 is the parallel bidirectional data bus (lower 8 bits only are used).
Rd, Wr, Rs (read, write, command/data) are the active low bus control signals.
CS is the active low chip select (always selected).
REST is the controller reset.

Power

I have run a 4.3 inch display from the Pyboard's 3.3V output for short periods but only when running the Pyboard from 5V. It's not recommended as the 4.3 inch display takes over 200mA at full baklight brightness which, with the Pyboard's own current draw, pushes the power dissipation of the Pyboard's regulator.

One solution is to power the Pyboard and the display from a common 3.3V supply. An efficient way of doing this is to use a Pololu switch mode DC converter: part numbers S7V8F3 or D24V5F3 are suggested depending on your input voltage range. If you adopt this approach there is an issue if using a USB connection to the Pyboard. In this case the Pyboard draws power from the USB cable, and its 3.3V pin becomes an output: the Pyboard 3.3V pin should be disconnected from the Pololu regulator output, which then powers the display only.

A debugging option which avoids this difficulty is to ignore USB and to use UART(1) via an FTDI adaptor, connecting only RXD, TXD and GND and powering the entire system from the 3.3V source.

If the system is always to be powered by USB an option is to connect a Pololu S7V8F3 to the Pyboard Vin pin (which will be an output in this case), and use its 3.3V output to power the display. If doing this, use a good quality USB cable capable of handing the current involved.

Pyboard Free Pins

Unused pins

The following I/O pins are unused by the interface and code:

Y5-Y8, X9, X10, X17-X22, P18-P21 (LED pins)
Ranges are inclusive.

Pins Y3 and Y4

The TFT driver's use of these pins is optional. If not using power control hardware edit tft_local.py to initialise the display with power_control = False. This will free pin Y4.

Pin Y3 is configured on first use of the TFT class backlight() method: to use this pin for other purposes simply avoid calling this method. This also leaves timer(4) free for use.