MicroPython Forum (Archive)

deshipu wrote: Yes, you can do it -- if you are using numbers. However, if you want to save space, at some point you will want to save this as raw
strings of bytes.

When you say, "as a raw strings of bytes", you mean like this? 010101010110
Does this save space, as opossed as using numbers? In code, i would occupy more characters, no?

deshipu wrote: At some point I would probably save this as one large string, something like this:

Interesting technique, to wich I am completely new. How do you convert it to hexadecimal, and, more importantly, how do you save it as "compiled bytecode"? I looked into and I found about pyc_compile. So you would use python 3.5, for instance, and compile some parts into bytecode? How do you then implement it into the project, by putting the pyc file somewhere?

When is this technique recommended, in your oppinion?

To convert it to a hex string experiment on these lines. The first step is to turn your DATA (which is a tuple of tuples) into a simple list, then convert that into a string which can be interpreted by Python: You'd save the string to a file with a .py extension and check that it can be imported into Python. To freeze the code you need to be able to create a firmware build. By far the easiest way is to grab a nightly build of the toolchain from here http://www.kaltpost.de/~wendlers/micropython/, get the latest source from Github and follow the README to compile it. To freeze your code, simply put it in the esp8266/modules directory and repeat the build.

May be you can consider using the export function of Gimp. Using the pbm export filter gives you a binary file with a short header. For example, a 128x64 image generates a 1073 bytes file.
The file has 49 bytes of header and following it the image is encoded eight pixels in a byte.
You can copy the file to the flashdisk and open it when necessary and just copy the data into the buffer no need to put the image in your code.

fdufnews wrote:May be you can consider using the export function of Gimp. Using the pbm export filter gives you a binary file with a short header. For example, a 128x64 image generates a 1073 bytes file.
The file has 49 bytes of header and following it the image is encoded eight pixels in a byte.
You can copy the file to the flashdisk and open it when necessary and just copy the data into the buffer no need to put the image in your code.

You can also export to .h or .c files, in which case you will get arrays with the data.

Creating a .py file and freezing it as bytecode has the advantage of not using RAM for the buffer.

This is a WiFi module. One could even http get to save RAM

[quote="mcauser"]@deshipu I'd like to test your modifications to the ssd1306 driver on my WeMos OLED shield (64x48).
I think I am missing a step.

[code]
>>> import ssd1306
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: no module named 'ssd1306'
[/code]

Do I need to copy/symlink the driver from /drivers/display/ssd1306.py into /esp8266/scripts and make/flash again to make it work?
Is that the same for all scripts in /drivers?[/quote]


I've got the same issue however it seems you solved it.

How exactly did you get the ssd1306 module onto the ESP8266 so that you can use the import ssd1306 without an error? I just want to drive my OLED using MicroPython and a ESP8266

I'm new to all of this, thanks!

you "simply" have to copy the file directly onto the esp. E. g. using webrepl. After that you can call it via import. Remember for webrepl you have to establish a network connection first and start webrepl on the esp. Sounds tricky but it is well described in the docs.

Yes, either
a) copy /drivers/display/ssd1306.py to /esp8266/scripts/ssd1306.py and make/flash
b) start a webrepl and upload the file
c) enter paste-mode on a REPL and paste the contents of the file

deshipu wrote:I didn't save the snippets that I normally use, but here's one that I recently used to generate data for a 2-bit font:

Code: Select all

import pygame

colors = {
    (0, 0, 0, 255): 0,
    (102, 102, 102, 255): 1,
    (204, 204, 204, 255): 2,
    (255, 255, 255, 255): 3,
}
image = pygame.image.load("font.png")
images = []

for tile_x in range(0, image.get_size()[0]/4):
    rect = (tile_x * 4, 0, 4, 6)
    images.append(image.subsurface(rect))
    
for image in images:
    print '(%s),' % ', '.join('%d' %
        sum(colors[tuple(image.get_at((x, y)))] << (x * 2)
            for x in range(4))
        for y in range(6))

Hai deshipu,can i have file 'font.png' for the code im still learn about pixel and need example