nano v3 with 1.44 lcd help

Other Hardware Displays
1

Hi me again.

I have a nano v3 with a 1.44 tft lcd which runs the st7735 driver.

I also have a nano ethernet shield that I want to use.

I have tried to get this combination to work but I am stuck yet again.

What pins on the nano do I wire this lcd to?

Will it work with the ethernet shield I have and would I also have a spare input to run a temperature sensor.

As I'm trying to make a system that displays the temperature on the screen and also uploads the temp to a website like initialstate that will log it all for me and display it on the website.

Thanks

2

The 1.44 128x128 displays will only work with 3.3V logic. They tend to have an ILI9163C controller.

Please provide a link to the display that you have got. And preferably the actual Ebay sale item.

You can always upload the sketch into the Nano's Flash via USB.
Then remove from the 5V USB.
Connect your module to the Nano. e.g. LED=3.3V, SCK=13, SDA=11, A0=9, RESET=8, CS=10, GND=0V, VCC=3.3V
Power the Nano with 3.3V

Gimpo has a "weird" 128x128 display that does not seem to have either ST7735S or ILI9163C controller.
If you run your Nano at 3.3V, I can post a sketch that will diagnose what you have got.

David.

3

I read that it can take 5v as it's the same as the adafruit 1.44 lcd that states on their website it can take 3.3 or 5v logic?

It's definitely as 7735 chip top.

Here is a pic of my nano with the ethernet shield connected and the lcd

4

According to the description it is 3.3v. But I have to run the ethernet shield too and that needs 5v?.

Also would I have a spare input for temperature sensors

5

There have been several threads on using the red SPI displays. e.g. 2.2" ILI9341, 1.8" ST7735, 1.44" ILI9163
The Ebay vendors all say that they are 5V compatible, and yes they are for the VCC pin.
But you still need 3.3V logic levels.

If you have a genuine Adafruit display, I would guess that they have sorted out any 5V tolerance.
The red Ebay displays have not.

You can use level-shifter chips, potential dividers, series resistors, ...
I suspect that you could also use an 8051-style Qasi output driver. i.e. use pull-up resistors with the AVR in Common-Drain mode. However you would get a lousy +ve edge on the SCK line.

You will find life is much easier with a 3.3V system. e.g. a Seeeduino, 3.3V Pro-Mini, ...
Or you could replace the LDO regulator on your Nano with a 3.3V version.

David.

6

Thanks David, but I would still need 5v for the ethernet shield?

7

You would need to read the spec of the Ethernet shield.

I bet that all the chips are 3.3V anyway.

All the options that I suggested would provide 5V power, 3.3V logic.

David.

8

Thanks again David. You are a great help.

Would one of these work?

9

Your link does not work. Please correct it.

David.

10

Try now David it should work. If you think it will work I will order it. I would just need to know what wires go where on it.

11

I have never used these. It should work ok. Let us know how you get on.

In fact, I think I will buy one for myself. It will be interesting to see how fast they will go.

David.

12

So there's enough pins etc and which pins do I link to it?

13

Look at message #1. You can omit the RST pin. Or connect to 3.3V with a 10k resistor. In fact, there might be an internal pull-up so you could just leave it n/c.

The ST7735 and the ILI9163 both have a Software Reset command.

Do the modules come in bigger sizes ?

David.

14

It looks like you can get lots of different sizes from 2 pins upwards

15

I just thought.. I have a bluefruit micro le , that runs 3.3v logic. But I'm not sure there would be enough pins for wlan or ethernet. Also as it has a Bluetooth low energy chip wouldn't that interfere with the screen on the spi?

16

No, that is the whole point of a BUS. You can have many passengers using one set of wheels.

You simply use different /CS pins for each device (passenger ticket).

You "chip-select" the BLE when you want to transmit something or you receive an interrupt to say it has received something. You de-select when done.

Likewise, the TFT screen is "selected" when you write something. It is de-selected when the writing is finished.

You just need to make sure that the TFT's CS, A0, RST pins are different to the ones used by your other SPI devices.

Most of the time you are either waiting for a signal from the BLE or asleep.

David.

17

Thanks again David, forgot about that! Just hoping there's enough pins for a wireless breakout and temperature sensors