GFX example

[Marcos Tadeo]

Hello

I am testing the nrf_GFX example with ST7735 

but the example has a ST7735 128x 160 and i have  St7735 80 x 160, I Change de dimentions in sdk_config.h

in the main I changed this 

I changed nrf_lcd_ili9341 to nrf_lcd_st7735

but dont works , i am thinking is the circuit connections or in the program, could you help me?, is there a secret? , i thought is change the lcd dimensions only

nrf52                      LCD

p1.6 mosi.............. sda

p1.0 clk................. sclk

p0.3 CD...............   cd

?          ................  res

?    ........................  cs

?      .....................  blk          

thanks and regards

[ovrebekk]

Hi Marcos

When you say it doesn't work, you mean to say nothing is happening on the display?

If there is absolutely no response it is usually a sign of a connection error, yes. 

Why do you put a question mark next to the cs pin? 
Your display should have a chip select pin (some times called CSN), and if you haven't set this one correctly the SPI communication will fail. 

Do you have a reference to the display you are using, so I can take a look at the specifics? 

Also, could you provide a picture of your setup, showing how the display is connected to the nRF52?

Best regards
Torbjørn

[Marcos Tadeo]

ovrebekk said:

Why do you put a question mark next to the cs pin? 

because when i was using ssd1306 128x32 over SPI,  the configuration 

mosi ---> P1.6

clk ----> P1.0

ovrebekk said:

When you say it doesn't work, you mean to say nothing is happening on the display?

yes, the display no shows nothing 

actualy 

RES --- vdd

CS --- P1.9

blk --- cdd

i am using this generic module 

I checked debug in main, i'm not sure if initialize the display(gfx_initialization())

in console dont shows a error

Display data sheet

thanks and regards ovrebekk

[ovrebekk]

Hi 

Can you try to connect a scope or logic analyzer to the SCK, MOSI, DC and CS lines to see if you have any activity?

Then you will quickly spot if everything is configured correctly on the nRF side, and if the various signals are connected to the right pins. 

Are you able to include the datasheet as an attachment to this case? 
I am not able to open the link (I am guessing you need to be signed in to open it). 

If you download the PDF you can just drag drop it into your reply. 

Best regards
Torbjørn

[Marcos Tadeo]

ovrebekk said:

Can you try to connect a scope or logic analyzer to the SCK, MOSI, DC and CS lines to see if you have any activity?

Yes I Checked the signals, and you right , I have a problem with CLK

I verified signals with a example in arduino and clk shows activity 

CS or SS Signal 

DC Signal 

MOSI Signal 

CLK no Signal no activity 

Datasheet-AR1716 (1).pdf

thank and regards 

[Marcos Tadeo]

Hello

Im sorry, in CLK there is activity , but is a low signal 

i take the signal directly of  nrf52 module , is this ok? 

[Marcos Tadeo]

I did it 

I changed output sck pin p1.0 to p1.10 

i have a port problem in P1.0

now i need to fix this 

i going to try it, 

thanks and regards 

[ovrebekk]

Hi 

Good work, getting something to show on the display at all is an important step. Then at least you know the basic communication is working properly 

Most likely something is wrong with the configuration of the display, such as the rotation, if the graphics is not ending up in the right place. 

If the color is incorrect it is usually an issue if the color mode, which is different from display to display. 

Best regards
Torbjørn