Adding text to display of Pimoroni Explorer base

Support
1

I am using a program with a Pimoroni Explorer Base with the modules DS3231, BME-280 and a SD card module.
The Break-out headers are not used.
The other headers are used as follows:
3v3 for the BME280.
An external +5V is used for the SD card module (did not work at 3v3)
SDA (GP20) for the BME280 and the DS3231
SCL (GP21) for the BME280 and the DS3231
MOSI (GP19) for the SD card module
MISO (GP16) for the SD card module
SCLK (GP2), not GP18, for the SD card module
CS (GP5) for the SD card module

Now I like to add some text to the display but it shows nothing.
How can I write some text to the display? Do I have to use reserved GP’s to realise it?

Additional info.
When I loaded only the button_test program from pimoroni-pico/micropython/examples/pico_explorer/button_test.py at main ¡ pimoroni/pimoroni-pico ¡ GitHub then still no display activity.
Then I removed all three modules and restarted the program. Now the display with the button_test.py works. I plugged in again the BME280, the button_test still worked. Adding the DS3231 then the button_test still worked. Finally the SD card module. The display was still showing “Press any button!” but pressing a button did not have any effect on the display now.
After a restart of the button_test program, at once the text “Press any button” was scrolling slowly from left to right and the textcolor was changing quickly between orange and green and the button press was detected.

2

The display on the Explorer base uses SPI, as does your SD card reader. The display uses:
GP19 Pin 25 LCD MOSI
GP18 Pin 24 LCD SCLK
GP17 Pin 22 LCD CS
GP16 Pin 21 LCD DC
It looks like you have some Pin conflicts? You can have two devices on SPI, as long as they are setup to share that BUS. Only one device can talk on the BUS at a time. I would say your SD Card reader is messing up the display.

3

Thank you.
I have changed the wires for the SD card modules. They are now moved to:
SCK_PIN = 2
MOSI_PIN = 3
MISO_PIN = 4
CS_PIN = 5
Now the MOSI and MISO are freed and can be used for the integrated display of the PIMORONI explorer base.
Then I added these lines:
my_pen = display.create_pen(255, 0, 0) # RED color
display.set_pen(my_pen)
display.set_backlight(1.0)

display.set_font(“bitmap8”)
display.text(“Hello World”, 50, 50, scale=2)

display.update()

and now the diplay is showing ‘Hello World’ in a red color, but the background of the display is WHITE.
How can I give that another backgroundcolor?
display.set_backlight(0.0) does not work.

4 
BLACK = display.create_pen(0, 0, 0)

display.set_pen(BLACK)
display.clear()
display.update()
5

That works. Thank you. Now I see that the display.clear() function is doing the background task.

1 Like
6

A good place to have a read is here,

You’ll find display.clear in the Function Reference section.
pimoroni-pico/micropython/modules/picographics at main ¡ pimoroni/pimoroni-pico