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by andybiker
Thu Jun 30, 2016 2:15 pm
Forum: General discussion
Topic: RPI Zero DOES have sound
Replies: 23
Views: 38761

Re: RPI Zero DOES have sound

The diodes are there to protect the GPIO pin and the CPU itself. If there is any voltage on the pin greater than 3.3v (plus diode drop) then this gets shunted to the 3.3v supply. Any voltage less than 0 (minus the diode drop) gets shunted to ground. Why put them on these pins? because headphones are...
by andybiker
Fri Jan 08, 2016 10:37 am
Forum: General discussion
Topic: RPI Zero DOES have sound
Replies: 23
Views: 38761

Re: RPI Zero DOES have sound

Maybe if there is a future revision then the missing resistors and capacitors could be added to the board. Even if the outputs came to solder pads then this would be enough. My own application for one (as soon as I can get my hands on one!) is to make a neater internet radio for my wife. The Pi Zer...
by andybiker
Thu Jan 07, 2016 3:28 pm
Forum: General discussion
Topic: RPI Zero DOES have sound
Replies: 23
Views: 38761

Re: RPI Zero DOES have sound

Maybe if there is a future revision then the missing resistors and capacitors could be added to the board. Even if the outputs came to solder pads then this would be enough. My own application for one (as soon as I can get my hands on one!) is to make a neater internet radio for my wife. The Pi Zero...
by andybiker
Thu Jan 07, 2016 2:00 pm
Forum: General discussion
Topic: Raspberry Pi Zero stocking?
Replies: 113
Views: 32980

Re: Raspberry Pi Zero

I would really like to get my hands on one of these. If anyone 'on the inside' is building a list of minor features to add on a newer version, How about adding the missing resistors and capacitors to bring back the analogue audio to pads on the pcb? The Pi makes an absolutely superb internet radio a...
by andybiker
Tue Sep 23, 2014 9:07 pm
Forum: Graphics, sound and multimedia
Topic: Controlling RGB Smart NeoPixels using Python
Replies: 10
Views: 13442

Re: Controlling RGB Smart NeoPixels using Python

I've dug out my 'scope after Joan mentioned an inter-byte delay and started investigating. I'm posting results here in case it helps others. The inter-byte delay is approx 147ns so, we can subtract this from the T0L and T0H times in the datasheets. choose the clock as 7352941 (closest to calculated ...
by andybiker
Tue Sep 23, 2014 2:35 pm
Forum: Graphics, sound and multimedia
Topic: Controlling RGB Smart NeoPixels using Python
Replies: 10
Views: 13442

Re: Controlling RGB Smart NeoPixels using Python

Now this really isn't fair. I've been trying to find a way of driving these (and realising I needed to do DMA transfers!) I find that there are 2 other ways! To add the dma-capable SPI driver see: https://github.com/notro/rpi-source/wiki/Examples-on-how-to-build-various-modules#dma-capable-spi-maste...
by andybiker
Tue Sep 23, 2014 11:36 am
Forum: Graphics, sound and multimedia
Topic: Controlling RGB Smart NeoPixels using Python
Replies: 10
Views: 13442

Re: Controlling RGB Smart NeoPixels using Python

I obviously misunderstood the SPI divisor thing. I thought it had to be divided by 2^n, not any even number. 7.8MHz is still in spec though (just!) I have just tried 10 leds and it works! that's 240 bytes with no glitches. Here's my crude test code. this lights 10 leds different colours (they are de...
by andybiker
Tue Sep 23, 2014 8:16 am
Forum: Graphics, sound and multimedia
Topic: Controlling RGB Smart NeoPixels using Python
Replies: 10
Views: 13442

Re: Controlling RGB Smart NeoPixels using Python

I don't know if you're still interested but controlling Neopixels (or WS8212B) from the Rpi IS quite possible! I have only strung 3 together so far and it works beautifully. I will try more later today. There is almost NO info on driving these directly from a Pi (unless somebody can correct me) Ever...
by andybiker
Wed Jun 19, 2013 2:45 pm
Forum: Other projects
Topic: HY28A-LCDB, ili9320 (working)
Replies: 131
Views: 41169

Re: HY28A-LCDB, ili9320 (working)

Notro, I would like to thank you for all of your hard work. I have the display working beautifully, the touchpad works in X11 and PyGame, all is good. The display is quite useable as a terminal being 320x200 I am having the same usb keyboardddddddddd problem that you have. I think we have to wait fo...
by andybiker
Tue Jun 11, 2013 10:54 am
Forum: Other projects
Topic: HY28A-LCDB, ili9320 (working)
Replies: 131
Views: 41169

Re: HY28A-LCDB, ili9320

Hi Notro, Please excuse me if I have things wrong (the last time I compiled linux kernels was the early 1990s) This line: sudo modprobe ads7846_test debug:0 cs:1 speed:2000000 model:7846 x_min:230 x_max:3850 y_min:190 y_max:3850 x_plate_ohms:60 pressure_max:255 gpio_pendown:17 keep_vref_on:1 is not ...
by andybiker
Mon Jun 10, 2013 8:36 pm
Forum: Other projects
Topic: HY28A-LCDB, ili9320 (working)
Replies: 131
Views: 41169

Re: HY28A-LCDB, ili9320

Notro,
Well Done!
It works very well.
A quick recompile and I have a working display.
Now I'll have to read up how to get the touch-panel working..
by andybiker
Sun Jun 09, 2013 7:59 pm
Forum: Other projects
Topic: HY28A-LCDB, ili9320 (working)
Replies: 131
Views: 41169

Re: HY28A-LCDB, ili9320

Hi Nostro, I'm glad to be of some small help! If the speed is as you say, assuming a clock of 12Mhz, 320x240 at only 8bpp, I think this gives a max of 19 fps [and this is only the theoretical max with no overhead] So we have a slow display which is a great shame as it is perfect size-wise for a pi. ...
by andybiker
Sat Jun 08, 2013 6:13 pm
Forum: Other projects
Topic: HY28A-LCDB, ili9320 (working)
Replies: 131
Views: 41169

Re: HY28A-LCDB, ili9320

Hi Notro, I'm a great fan of your work. I've just got one of these displays to try, there seem to be two different types of 2.8 inch display. the spi one claims to use ILI9320 and the 16-bit parallel one uses SPFD5408B The example code mentions the following chip IDs #define ILI9320 0 /* 0x9320 */ #...
by andybiker
Tue Apr 30, 2013 8:55 pm
Forum: For sale
Topic: 1.8" TFT LCD Shield board
Replies: 31
Views: 39289

Re: 1.8" TFT LCD Shield board

These are superb displays. I had mine working the same day I had it. Just enable the display and edit the cmdline.txt (in my case add a rotate here and select a smaller font) I now have my Pi internet radio with a nice colour display. I just need to learn a little more Python to format the screen ou...
by andybiker
Fri Apr 26, 2013 8:15 am
Forum: For sale
Topic: 1.8" TFT LCD Shield board
Replies: 31
Views: 39289

Re: 1.8" TFT LCD Shield board

Hi,
I would like to buy one from you but I'm a new user so cannot PM you.
Can you help?
Andy

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