new Kickstarter board good for MicroPython?

[jeffm]

This looks like it would be an interesting platform for a MicroPython implementation:-

https://www.kickstarter.com/projects/th ... y-with-tou

"Blaze is a miniature, high-res 1.6" 240x240 display with capacitive touch, a powerful 120MHz Cortex M4 micro with GPIO and storage."

I have signed up for two, so I would have a strong interest in getting MicroPython ported to it:-)

[platforma]

35 pounds is a little too expensive for something like that. It's an M4, so porting stmhal to it shouldn't be too difficult.
You are throwing away all his advertised API, Arduino compatibility layer. So what are you actually buying? A bare Cortex M4 board basically with a display shield. It would have been more beneficial to write a driver in micropython for one of those displays, if not already written, and attach it to any board that can run micropython.

[jeffm]

Firstly, apologies, I had mean't to post this to Other Boards.

To answer the previous point, the display is a capacitive touch screen and I have only found cheap displays with resistive touch and in addition, the display and processor board are nicely integrated which is worth something.

However, overall, I agree that this would be a more compelling proposition if the project had gone for higher volume and thus lower cost.

[pythoncoder]

An issue for any display interface is the way it communicates with the CPU. For performance you need a shared memory architecture rather than via a serial interface such as I2C. Any "shield" for the Pyboard would be forced to use the latter. The performance figures they quote for the Blaze suggests that they may be using shared memory.

A Blaze MicroPython port would need to take advantage of their C display code for decent performance; this would involve writing a Python compatibility layer. Not the end of the world, but a factor to consider.

A point to note is that tasks like font rendering aren't too quick in MicroPython going by my experience with the e-paper display driver, partly because RAM availability constrains the techniques you can use. They must have found a way round this (aside from using C). They are doubtless more skilled at graphics coding than me And they might have done things like storing font bitmaps in flash optimising speed over flexibility.

I'd like to know more about how it works...

[dhylands]

The 405 chip includes something called DMA2D which is specifically designed for blitting to shared display memories.

Personally, for about the same price $61.25 US) you can get a 469 Discovery board:
http://www.st.com/st-web-ui/static/acti ... 218382.pdf

[torwag]

Hi,

I moved it to Other Boards as suggested by the OP.

I too thought directly about the 469 Discovery board. In addition I'm wondering wether the display might contain its own processor. There are some "smart" displays on the market which removed the workload form the microcontroller but sure adding constrains.
Without knowing exactly how the display is connected to the uC, it is hard to get an idea whether this is a good idea or not

[kwebster83]

Hi,

I'm the guy currently running the Blaze Kickstarter.

I just thought I'd answer some of the questions about the display. The external parallel bus interface on the Cortex-M4 is used to drive the display and runs at 60MHz - hence the fast refresh rates. As someone already commented, a C-to-Python compatibility layer would be needed in order to make use of the low-level drivers and efficient drawing routines (fonts, bitmaps, etc).

Obviously, I do appreciate that there are other "smart-display" boards out there but nothing that I'd come across with a capacitive touch 1.6" display - I personally think these little displays are fabulous. I'd love to be able to compete price-wise with the likes of ST but the manufacturing costs, BOM costs and cost of the display severely restricted this. If I was to manufacture 1000+ boards then its a different story.

I'm also advocating British manufacturing too, which is well known to be more expensive than manufacturing in China, for example.

I'd love to read more comments though. Everything is taken on board and I shall endeavour to try and make Blaze even better.

Thanks,
Kevin

[lbattraw]

The 405 chip includes something called DMA2D which is specifically designed for blitting to shared display memories.

Personally, for about the same price $61.25 US) you can get a 469 Discovery board:
http://www.st.com/st-web-ui/static/acti ... 218382.pdf

I'd like to add that the F746 discovery board (STM32F746G-DISCO) is available for about $50; it has a capacitive 480x272 LCD onboard (As opposed to the 800x480 for the 469 board) with the same amount of off-chip flash/RAM as the 469 board (16MB/16MB), 3 USB connectors, stereo in/out, microSD, as well as an onboard ethernet port, which is interesting. Of course MicroPython support is always a question, particularly since I'm not sure how much work it would take to port from the STMF324xx series to the 7xx as well as dealing with TCP/IP for the ethernet port since that tends to involve considerably more complexity to handle packet scheduling via a RTOS. The WiPy uses a Ti chip and FreeRTOS + lwip to do so but it's definitely a non-trivial porting effort to try it on a different manufacturer's chip/board.

If you're interested in a working 4xx board with (early) LCD support the 429 discovery board has 8MB of off-chip RAM and a 320x240 resistive LCD that also has very fast display updates if DMA is used; the demo it ships with has a ridiculously high FPS for a filled polygon demo, can't remember offhand the exact figure. It goes for about $25 but apparently they've just discontinued the DISC0 version for a slightly more expensive DISC1 version ($29), not sure what the differences are since there's no info on ST's site and Digikey only has the "0" version data sheet.
Anyway basic support for the LCD has been recently added thanks to some talented folks on this forum: http://forum.micropython.org/viewtopic.php?f=12&t=1265
I've tried it out and it works well, very nice to have a board with support for the LCD baked into MicroPython. It's the only one I'm aware of, though if anyone knows of others please let us know.