Futaba vfd serial how to#
Futaba vfd serial install#
Futaba vfd serial serial#
Futaba vfd serial drivers#

Futaba vfd serial serial#

So, for us serial interface users, that means send 0xF8 followed by 0x01. The datasheet has a table called “Software Commands” that explains which values of RS execute which functions.įor example, according to the datasheet writing the parallel interface with RS set to L with 0x01 sent causes the display to clear. The RS pin is an artifact of the device’s parallel interface, but it’s important because this pin controls which functions are executed when we send the next byte. 0xFA corresponds to the RS pin being high and 0xF8 corresponds to the RS pin being low.

For the connections we diagrammed above, both of these arguments are zero.Įach write to the display involves sending two bytes. the key bit of this code is the call to spi.open(), which include an spi device number and a spi chip enable number. Fortunately, we don’t have to bitbang the protocol we can just call write() functions on the spidev module and the pi will handle the low level details of the protocol.

Futaba vfd serial how to#

That’s the module that knows how to talk on the SPI bus. At the top of the file, there’s an import statement for the spidev module.

Let’s take a look at some of the more important bits. Vfd.setPosition(int(sys.argv), int(sys.argv)) Here’s the module that I put together (note: check github for the most recent version the code below will likely become outdated): import spidevĭef setDirection(self, leftToRight, autoScroll):ĭef setDisplay(self, display, cursor, blink):

Futaba vfd serial drivers#

I cobbled the information together from a combination of the data sheet () and some C drivers floating around on the internet. I’m primarily a python programmer these days, so I put together a python module to operate the display. Now we should have a raspberry pi with the SPI module being loaded automatically, and the python library installed. For a newer raspian you might want to run raspi-config and use the advanced options to enable the SPI driver instead of editing /etc/modprobe.d/nf. Note that this is for a somewhat dated Raspbian running on one of my old B models.

Futaba vfd serial install#

# now let's build and install the python-spi library # update our distro and install python development tools # make sure the spi driver will be loaded Now we need to configure the pi to enable the SPI driver. I chose a 1K ohm resistor as that seemed sufficient to limit any current flow. I read several different web references on which resistor to use, with recommended values from 470 ohm to 10k ohm. If we ever entered a state, perhaps due to a programming error where the pi and the VFD were both outputting to the same pin with different values, a high amount of current could flow and the GPIO could become damaged. The Pi on the other hand has a dedicated send pin (19) and receive pin (21). Pin #2 on the VFD is biderectional - sometimes it’s used to send data while other times it’s used to receive data.

The reason for this is that we’re interfacing a 3-pin SPI device to a 4-pin SPI device. Note the resistor inserted on the connection to Raspberry Pi ping #19 (MOSI). The VFD display requires two pins for power (+5V, GND) and three pins for IO (SI/SO, SCK, STB). Note that we’re viewing the module from the back side, so pin 1 of CN1 is to the left and pin 6 is to the right. I was able to pick up this display for $35 on ebay.Ĭlick the diagram above to get a larger, more readable version. Using an SPI interface only consumes three or four of the pi’s pins depending on how you wire it. This is a 2×16 character display that interfaces via SPI or Parallel. The first thing to do was to select an appropriate display.

They often have a blue/green character color. They differ from LCDs in that LCD displays typically have a backlight whereas a VFD emits light directly, in a similar manner to how a fluorescent light works. VFDs are an older technology that has existed since the early 1960s. VFD stands for “Vacuum Fluorescent Display”. I figured just to be different I would try a VFD display. There were many options for a display - I could go with an LCD, an OLED, etc. I’m in the process of building a home automation controller using my Raspberry Pi, and I figured it would be cool if it could display the current song and artist on my Pandora player.