LCD display and buttons in Python (tutorial and code)

[XploD]

[hondagx35]

[XploD]

Oh I didn't even see the whole picture, I took a look only for an error and didn't see it was in console of PC instead SSH.

[Hairybiker]

Thanks for the code.
I have hacked it about to use my i2c LCD's (both 2x16 &4x20 currently only uses the 1st 2 lines but that could be changed)
If anyone is interested I will post the mods and new library (to interface with the i2c controller)

[XploD]

You're welcome. I just ordered 2 4x20 LCDs from eBay and a few paralel to I2C converters from eBay and the semester on my college is over so I'm going to continue to work on this. Have you noticed any better performance on I2C? If you want, you can post your code for I2C so I can see which one did you use. I hope that it should work better on I2C since it's hardware implemented on Pi and it should reduce CPU load.

Unfortunately, it will took some time for the LCDs to arrive (15-25 days) but in the meantime, I will try to fix buttons, auto-start on boot and I will experiment with another informations for lower 2 rows. Also, I will try to connect LIRC and Python to receive commands from IR remote so I will try to achieve turning on/off shuffle/repeat and other as well as changing playlists/folders with remote.

Also, tomorrow I'm going to buy transistors and resistors so I can be able to turn-off LCD backlight or even control it's brightness using PWM on Pi. When paused or stopped, after few seconds the backlight will go off automatically so I could sleep during night

And yes, I ordered parts for hardware SD cards switcher, since is not possible (at least no one succeded AFAIK) to do a dual boot with OSMC so I will use a microcontroller to switch between 2 different cards.

[Hairybiker]

[Hairybiker]

I have been looking at your scrolling routine, trying to make sense of it

You reuse the same code several times in the Artist/Title scroll, wouldn't it be better to make a function for that?

I also couldn't figure out how your scroll actually works
Is this right?
counter[1] is the x position
direction[0] is 0 - normal 1 - back

but couldn't figure out HOW it works, can you enlighten me please.

[XploD]

Thank you for your code and explanation! I ordered that same i2c module (3 pieces), now waiting for it and the display to arrive.

My code is a mess for a few reasons: I'm new to Python and new to all this (coding for GPIO on Pi) and when I'm working on something new, I'm not careful with code tidiness. I use try-and-see-what-happens method After I finish with everything, I'll work on making the code more tidy.

So yes, I have a reused part of code; the same thing is for artist and title. direction, counter and framebuffer are arrays with 2 elements: 0 is for first line and 1 is for second line. counter is a position, yes, and direction is 0 for normal and 1 for back as you said. The code is absoluetly the same for both lines so I will explain on first one. First I check if artist name is longer than 16, if it is, then I check if currently a file is playing, or if the radio is playing, I check if radio scroll is enabled. Then I take a 16 charachters long part of the name, starting from position[0] till position[0] + 16 into framebuffer[0]. If direction[0] is 0, then we scroll forwards and first I check if I reached the end (artist_length - 16) and if I did, I change the direction. Otherwise I increase counter[0]. So, depending on the counter, in first pass it will take a part of the artist from 0-15, in the next pass 1-16, then 2-17 and so on.

If artist name length is exactly 16, then I took the whole name into framebuffer. And last, if it's smaller than 16, then I took the whole name and fit empty places with spaces. At the end, I print both framebuffers into first and second line repsectively, and let it sleep for a while (scrolling period).

[Hairybiker]

Cheers for that, yep I am new to Python as well, I used to program in C about 20 years ago, but not done much recently. I wanted to learn Python and this looked like a good way to do it.

I have rebuilt my library to make it more consistent and will try and add your bi-dir scolling then up load it again.

[XploD]

To my shame, I'm an engineering student and a programmer But I usually program in PHP, Java or C. But I'm usually lazy so as I said, when working with something new, I'm to lazy to create functions, classes or similar so I just write a code in a way I think. Once when I know what I'm doing, then I rewrite the code to be more clean.

While waiting for display, I will try to make the code cleaner and I will experiment with LCD backlight dimming and with fetching other infos from MPD.

Also, my laziness is the reason why my hardware is on a proto board. I created it like this to test it and now I'm too lazy to solder it onto a board and create a chasis for all together