Sunlight Readable Display

[John Nicol]

Maybe try another Pi if you have one to determine if it is the GPIO pin on the Pi. Also potentially try the image without XCSoar installed first. Sorry that is all I can think of right now.

[K6Eler]

I made a test with the new SD-card from my second display.
Same problem without installing XCSoar.
I ordered a new Pi3 and will receive it latest on Monday.
Interesting is that the rasbian needs about 30 min for necesssary updates.

[caz]

Which pins in 40p connector the display use? GND, 5V, 3.3V, 12=gpio18=pwm, 3=gpio2=i2c sda, 5=gpio3=i2c scl, 7=gpio4=int, 11=gpio17=rst. Are they all? I am planning to connect the display by wires because USB, Ethernet, 3.5mm, Micro HDMI and USB type C connectors are hanged out and want to have HAT.

[John Nicol]

Hi Caz,

The pinout is on the back of the board itself:

[caz]

The touchscreen will not work when you run "apt upgrade". The micro SD image and its origin, the latest raspberry pi OS image dated 2020-08-20 has Linux kernel 5.4.51. When you run "apt upgrade", the version goes up to 5.4.72. Between 51 and 72, logic level of RST(gpio17, pin 11 of 40p connector) is inverted. As a result, the touchscreen does not work.

The touch screen works when I build and install the 5.4.72 kernel with reverting the logic inversion.
-caz

[John Nicol]

Github may be a better way to distribute the SD image. Especially if the goal is to ultimately move this to a set of packages that load on top of a stock Raspbian image, which would be the best route.

No unfortunately, GitHub isn't a good place to store o/s images. I was actively encouraged not to put the image onto GitHub.

[John Nicol]

The touchscreen will not work when you run "apt upgrade". The micro SD image and its origin, the latest raspberry pi OS image dated 2020-08-20 has Linux kernel 5.4.51. When you run "apt upgrade", the version goes up to 5.4.72. Between 51 and 72, logic level of RST(gpio17, pin 11 of 40p connector) is inverted. As a result, the touchscreen does not work.

The touch screen works when I build and install the 5.4.72 kernel with reverting the logic inversion.
-caz

Hi Caz,

Updated drivers are now available which should solve any issue using the screen with newer pi images and updates. See the Sticky Post in this forum topic.

[Snowflake6]

EDIT: NOTE I HAVE UPDATED THE PI 4 SETTINGS BELOW TO REFLECT AN UPDATED CONFIG FROM THE MANUFACTURER.
...
The backlight brightness can be controlled using the following commands on raspberry PI 4B:

gpio -g mode 18 pwm
gpio pwmc 4095
gpio -g pwm 18 X

where X is the brightness required 0= brightest, 400=darkest.

I have the new display up and running on my Pi4. The Pi4 booted up just fine out of the box with the included SD card.

I note that in the above you say that 0 is brightest, and 400 is darkest. That doesn't seem to be the case. Based on the settings for the Pi3, I tried X=600 and X=1000 and it gets darker yet. 1000 is almost unreadable.

Is it possible that 1024 is still full black, as on Pi3?

[John Nicol]

Good catch! Looks like the information from the manufacturer was incorrect. I just tested on the Pi4 and the settings are the same as the Pi3. The pmwc number is still valid at 4095. I will amend the web page and change the sticky announcement.

Cheers!
John

[Snowflake6]

Good catch! Looks like the information from the manufacturer was incorrect. I just tested on the Pi4 and the settings are the same as the Pi3. The pmwc number is still valid at 4095. I will amend the web page and change the sticky announcement.

To make this easier, I created a script to change brightness in the short term. I saved the following into brightness.sh in my path:

---
#!/bin/sh
gpio -g mode 18 pwm
gpio pwmc 4095
gpio -g pwm 18 $1
---

Don't forget to chmod +x brightness.sh to make it executable. Then you can just type "brightness.sh 400" to set brightness to 400.