Missing SPI Transactions (Library Freezes With Other SPI HW Devices)

[glowdeck]

This library was probably written before the new SPI transactions protocol was published, but without that protocol, this library only works if the display (in my case, the ILI9341) is the only hardware SPI device connected to the microcontroller. Add a second SPI hw device, and Pixels isn't able to reassert control of the SPI port.

The general method is pretty straightforward -

// Call this before you start an SPI read/write operation
SPI.beginTransaction(SPISettings(SPICLOCK, MSBFIRST, SPI_MODE0));
[Insert SPI communication code...]
SPI.endTransaction();

I was able to get the drawCompressedBitmap function working with SPI transactions, but I really need the fonts and text printing functionality to work too (and I had less luck with that). Any chance of updating the library to support SPI transactions?

[zxfr]

Thanks a lot for your input and my apologies for the delay with the reply: recently I was focused on positioning/orientation logic refactoring and did not expect it will take that long.

if you have a possibility to investigate further the topic with the newest library state - I am ready to assist you. But unfortunately currently I have no time to do it by myself.

My next planned activity (from the beginning of April) is a fine performance tuning of the newest code and only after that I'll have a chance to pay attention to the communication protocols (SPI transactions, SPI direct memory access etc).

[glowdeck]

I successfully implemented SPI transactions into the Pixels library with as few modifications as possible. Now my version of the library plays well when mixed with other devices that share the SPI bus.

I just noticed you pushed a bunch of changes 6 days ago - if you're interested in updating Pixels to use the modern SPI transactions method, I can send you the library I modified before your logic refactoring work, and maybe you can put the pieces together? Feel free to email me at jmkauf@gmail.com