Interfacing with Seeed Studio TFT Touch Shield 2.0

Status
Not open for further replies.
S

SoftEgg

Member
Has anybody managed to interface the Seeed Studio TFT Touch Shield 2.0 with the Teensy?
I've been trying to determine whether it is 3.3V tolerant or not, but am getting conflicting information.
The Wiki says it needs 5V. It also says that it uses an ILI9341 driver, but the ILI9341 is a 3.3V part according to the datasheet.
The box says it uses an ST28017 driver, which I cannot find a reference for.
From the schematic, it looks like their board may have some voltage regulators to bring the 5V down to 2 and 3 volts.

If I supply those with 3.3V, will it just regulate them to stay the same?
And will it work with the levels output from the Teensy digital pins?

Does anybody have any insight before I try to wire it up and blow up both parts?

-- Tim --
SoftEgg LLC
 
Looks like it ought to work, if you just wire the 6 TFT signals to the same pins on Teensy as the normal ILI9341 display. Whether reset is really required is a good question. I'd wire it to a Teensy pin and use the full 6 pin constructor.

The docs seem to say MISO, MOSI and SCK are only connected to the 6 pin socket. But you could short those little solder jumpers, to get them onto pins 11, 12, 13, which are probably much easier to access.

Clearly that shield is meant to use 5V power. It creates the lower voltages.

I didn't see documentation on which buffer chips they used. If they're slow CD4050, then you might not be able to run at 24 MHz SPI clock speed. You might need to use Adafruit's slower library, or edit the ILI9341 code to use a slower clock speed. Or just run Teensy at 24 MHz (from Tools > CPU Speed), which will limit the SPI clock on Teensy to only 12 MHz.

While testing, make sure you do *not* have a SD card in the socket. That's only asking for trouble. Likewise, the buffer chips might not handle the 24 MHz speed, so if you use the SD card, you might also have to limit the SPI clock speed.
 
Status
Not open for further replies.
Back
Top