MicroPython Forum (Archive)

1) Fast SPI transmission rate. The ESP32 is capable of 80MHz SPI rates though I'm not sure if we can achieve that in MicroPython today. If my back-of-the-envelope math is right at 80MHz a complete frame ought to take less than 10ms (100fps!). It's more complex of course - the ILI9341 I intend to us...

That looks like a much more reasonable form factor than the original PyBoard.

With such a large display, you are likely to have problems with memory if you use the naive approach of just drawing your ui on the display. However, if you can redesign your UI so that it can be represented as a tiled grid of similar images and some sprites, you could make use of my "stage" library...

I'm actually not using UART anywhere in that workshop, with a library or without, and that is because MicroPython's support for UART on the ESP8266 is atrocious and certainly not anything I would recommend to beginners.

Last time I checked we had at least 4 different monochrome modes in there.

@dhylands Have you seen PR4020 ? This addresses the issue of efficiently prepending a command to a buffer such that an I2C stop does not occur between command and data. This is another workaround that only solves the visible problem, but doesn't even try to get into the actual issue. It still force...

My understanding is there are 2 problems here. How much memory is required to store the entire buffer (for a 1-1 copy) and how to efficiently send the buffer over the common buses I2C, SPI and UART. The second problem is self-inflicted and can be easily solved by adding a bit of C code to the frame...

Why don't we just allocate the framebuffer with some number of "header" bytes which could be used to store the i2c commands? I'm not sure I follow. Care to elaborate a little? Lets say you want a 128x64 pixel (1 bit per pixel) frame buffer. For the actual frame buffer, you need to allocate 128x64/8...

dhylands wrote: ↑

Mon Aug 13, 2018 7:52 pm

Why don't we just allocate the framebuffer with some number of "header" bytes which could be used to store the i2c commands?

I'm not sure I follow. Care to elaborate a little?

My hope was to use framebuf as a general purpose object for creating, storing and manipulating image data, similar to PyGame's Surface objects, which then in turn could be used as building blocks for more advanced display drivers and frameworks. For example, you could use it to store images of butto...