For what it's worth my own weekend of figuring this out has produced the following.
I will say up front that I am not claiming to be an expert. If there something unacceptably incorrect here please let me know so others don't spend a weekend on this.
Make sure you understand how to orient the module on the RPi2 connector. Hint: it should cover the RPi2 board with the RPi2 connector on the lower right as you look at it. Connect the display to the rightmost pins leaving a few to the left uncovered.
"You've just got to know that" is not a good answer. These boards are for people who are just getting started in this world. I have been playing around with stuff like this for many, many years and it was not obvious to me at all. It's a few extra lines of documentation.Making the connector larger was a good thing but maybe something on the silk screen of the board showing which end is the legacy end might help people out.
My environment is a RPI 2 with the PID 1601 Adafruit 2.8" display.
My first suggestion is for all of us to agree on what to call these things. The various supposedly authoritative sources on using the fbtft driver have at least three different ways to refer to the display. That's just going to generate support requests. My suggestion is to call it something like ada-28-1601 or something similar. Adafruit should also put the PID (really isn't it a SKU?) right on the board where you can read it. I had to go back to my sales order to find which display I actually bought since there are a couple of versions that look identical. That's especially important in this case when the only difference between the units is the touchscreen it employs.
The numerous documentation sources are not, repeat, not dealing well with the integration of fbtft into the Linux kernel. The nearest I can tell the most authoritative place is https://github.com/notro/fbtft/wiki/fbtft_device
The overall documentation situation needs work. I'm hoping that this note is a starting point. I don't have the expertise to do a thorough job.
I have the display mostly working with my RPi2 using the following....
Base Jessie distro downloaded from the Raspian site. Here's my 'uname -a' info....
Linux raspberrypi 4.1.7-v7+ #817 SMP PREEMPT Sat Sep 19 15:32:00 BST 2015 armv7l GNU/Linux
Here's the relevant part of my /boot/config.txt...
Code: Select all
/etc/modules is unchanged. I have no idea if that's right or wrong. It looks to me like the Device Tree overlay makes this unnecessary but I could be wrong about that.
Set the RPi2 up to boot to a console with the user logged in. Follow the procedure documented here...
This will get X setup such that the 'startx' command will work and X will come up on the display. I'm still figuring out how to get everything right here because it's trying to cram everything onto that tiny screen. Obviously I need to learn how get everything scaled properly.
That Wiki is the most authoritative site which makes sense because it's the site maintained by the person who wrote the driver. Lots of good information however the assumption is that you're a pretty literate Linux user with some knowledge of how Linux works at a systems level rather than just a hardware enthusiast level.
I love Adafruit but they need to seriously work on how they present the setup for these things. Yes, their image will get the display to work but I think the warning about not using the update tools after the installation is a show stopper. We're just adding another display and doing so should still allow us to work within the maintenance infrastructure that's out there.
Where I am now:
X works with the display although not optimally.
I can't get mplayer to run any videos on it.
I hope this is helpful. I felt compelled to write this because I have taken advantage of a lot of work by other people who work very hard to make all of this information available. It didn't seem right to not share my notes from my workbench.