jeffmer

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• Low power display for Puck (ST7302)

  @jeffmer started

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  @jeffmer replied
• Low power display for Puck (ST7302)

  in Projects • 2 weeks

  

  Happy it works for you. I have just updated the ST7302 V2 driver with a version that improves performance at the expense of a more complex C update function. It now takes 128ms to render rhe example with g.flip now taking 31ms (it was 49 ms in the previous version).

• Low power display for Puck (ST7302)

  in Projects • 1 month

  

  That works great - many thank s- I did not know you could access the hidden root that way!

  I tried another version of the ST7302 driver which uses an image buffer in addition to the screen mirror buffer. This version only copies the updated part of the image buffer into the screen buffer put still blits the whole screen buffer in g.flip.

  This version reduces 550ms to 146ms which is much more useable and has better power consumption at the expense of the additional 4000 byte buffer.

  The new version is in the repository here. I am sure the update function can be optimised using some of your bithack code.

• Low power display for Puck (ST7302)

  in Projects • 1 month, 1 week

  

  The display background is not as white as an Epaper display but it is very clear and the background is similar to that in the original Kindle. It is not as "dull green" looking as the Pixel or old Nokia displays look in some lights. I do not have a Pixel so that is from photos!

  The current code is useable in that it takes 550ms to draw the clock and widgets on the screen shown above of which only 10ms is need for the g.flip() call. Clearing the screen i.e. g.clear();g.flip() takes only 30ms. So a lot of the time in drawing text is probably the Espruino interpreter calling the C setPixel() routine.

  I will try your ingenious code above to see if it works:-)

  BTW: I want to try to see how using the screen as a Terminal might work. I have built a version of the PUCKJS firmware with the TERMINAL module but I cannot see a way to set the graphics instance that Terminal uses. It seems to assume it is built in. Is there a way of setting the instance from Espruino?

• Low power display for Puck (ST7302)

  in Projects • 1 month, 1 week

  

  @Gordon I have not seen a bigger display for sale, however, I found this presentation from the manufacturer which refers to larger and even colour displays using the same technology.

  Yes, the C -code is due to the odd layout - its sort of interleaved as well with bit 0 of a 24 bit chunk in one column and bit 1 in the next. There is a good write up here in Technoblogy where I noticed the display.

  It would be great if the fill/setpixels code was included in Espruino in some way as it would make the driver much faster.

  PS Very happy for the ST7302 module to be included in the Espruino module library although not sure how that works with embedded C.

• Low power display for Puck (ST7302)

  in Projects • 1 month, 1 week

  

  Thanks,

  Have not tried that one.
  The pixel.js display is much lower resolution (128x64) and has a backlight so I think this would be a much better display for a Pixl.js V2!

  BTW. I am using HW SPI at 10Mhz to update the display which works well. I am thinking of trying to connect the display to one of my old NRF52832 watches to get the extra flash memory.

  PS.I think the time display above may be adapted from some of your code - look familiar?

• Low power display for Puck (ST7302)

  in Projects • 1 month, 1 week

  

  The 2.13" (250 x 122 pixel ) reflective display shown below connected to a Puck.js V2.1 has an ST7302 hardware driver. The display is similar to a Sharp Memory Display in that has no backlight and it permits much faster updates than Epaper displays.

  It is also much cheaper than the Sharp displays - I got three from Aliexpress for less than 20 pounds (incl. postage and tax). Just search for ST7302 display.

  

  In low power mode with frame refresh set to 4Hz, it uses on average 30 microamps. This is a versatile display, in that, in high power mode it can update at a 32Hz frame rate with current consumption still less than 1 milliamp.

  The driver and example code can be found here

• Starfield Collectors Edition watch runs Espruino

  in Other Boards • 1 month, 4 weeks

  

  I will look for in my photos. I am afraid that I have gifted both the GW32 watches I had. @fanoush may have a picture as I am sure he has one.

  Found this one due to @yngv126399:

• Is shared SPI working?

  in Other Boards • 6 months, 3 weeks

  

  Hi, Gordon rightly thought that switching between HW and SW SPI was a bit of a hack and that a more elegant solution would be to see if SPIFLASH code could use HW SPI when sharing SPI was necessary . I did not get round to looking at that and as @fanoush mentions, the HW/SW hack is not in the main Espruino repository.

• App ideas - free of charge

  in Bangle.js • 7 months, 4 weeks

  

  I think it would be a nice extension to consider tag groups as folder icons in the the desktop metaphor as you suggest. Entirely up to you as to which app you base it on.