Hi Everyone, I've been using the SPI_VFD for quite a while now, but have never utillized the "keyscanning" options. I know how to put the VFD driver in read mode, and can write to the display with no problems. My question is more about straight forward "HOOKUP of the Dout". Do I connect the Dout of the display to the same pin as the Din on the 328, and just flip/flop pin 3 (data) between input and output. OOOOrrrr, do I connect it to somethin' else? aahhh, I'm still psychologically impaired from my last 2n2222 schrapnel wound. Thanks in advance.
I've been using the SPI_VFD for quite a while now,
Who’s version, link please.
Do I connect the Dout of the display to the same pin as the Din on the 328, and just flip/flop pin 3 (data) between input and output. O
Don’t know given I don’t know what you have exactly, but it sounds highly unlikely.
HI G_mike, sorry so vague, I honestly did not know many versions of the SPI_VFD existed. I've been using the version I've had for 10 years without an issue. the version header says, Originally added by David Mellis 2008, the link points to www.ladyada.net. Modified by Tom Igoe 2010.
I'm using an old, KOSS face plate from an old carousel style DVD/CD player, along with a DIY (non-USB) ATmega328P set-up. The faceplate uses the uPD16315 VFD display driver.
Sorry still not enough for me to track down. I googled:- SPI_VFD keyscanning and found exactly 3 hits, this thread being one of them.
the version header says, Originally added by David Mellis 2008,
What version, I assume this is some libiary but what is it called?
the link points to www.ladyada.net.
I tracked down this libiary GitHub - adafruit/SPI_VFD: LiquidCrystal port to SPI-controlled VFD display but I could not find any reference to keyscanning, so I am stumped unless you can provide more information.
G_Mike, thank you so much for your time, but for the very reasons you stated above, is exactly why I've created this post. There's numerous info on how to write to The VFD uPD16000 series driver chip, but little to no info on how to acquire the keyscan(button pushing matrix info) for the same. I've attached the uPD16315GB datasheet in PDF, there's plenty on "keyscanning" for the driver chip in it. Most of what I learned about getting these displays to work came from Hackaday. My theory is it has something to do with Grid 12, because it's the only grid that doesn't have a display section, just a theory though. The buttons on the faceplate are scanned to see if a button has been pushed, and sends that info,"Out" to the arduino(ATmega328) so some function can be rendered. I sure this must be where I use "ShiftIn". This Info must be sent via the Dout of the uPD16315 driver chip to the Arduino(UNO). I will try to include in my next post some illustrations.
uPD16315GB.pdf (95.8 KB)
Thanks I think we are getting somewhere now.
What you want to do is to connect the Dout line to Master In Slave Out MISO pin of the Arduino’s SPI interface. There should be nothing connected to that pin at the moment. Then an SPI output command will return the value from the previous write. See this for more details SPI - Arduino Reference
Page 17 shows the circuit for each matrix intersection of a diode and push switch. The results of a scan is stored in four bytes of memory. You read this memory with a read command shown on page 11.
Hope that helps.