Display-O-Tron 3000 pins - gpio pins


#1

Hi
Where can i find a data sheet / pin configuration for the Display-O-Tron 3000?
Could one change a gpio-pin (when its already in use) ?


#2

I think it uses i2c apart from the joystick, you can work out which pins the joystick uses from here; https://github.com/pimoroni/dot3k/blob/master/python/library/dot3k/joystick.py

@gadgetoid or someone may be able to help you with the chance of changing the configuration.

Gordon


#3

Thanks,
beside the joystick what pins are used for lcd itself?


#4

Have a look here; Dot3k Pins looks like it’s I2C and SPI plus the GPIO for the joystick.

Gordon


#5

Not sure what you mean by changing a pin when it’s already in use?


#6

I will rephrase. I am already using some gpio pins on the raspberry pi board.
In order to connect the display-o-tron 3000 i have to connect it myself using wires and I assume not all 26 pins are used for the dot3k. this is why i would like to see a data sheet, so I can see what pins have to be connected. now what i mean is i am using pin (gpio 2 and 3) already if the display wants to connect to gpio pin2,3 too, is it possible to change it and connect it to 29 and 31 instead etc. is there not a data sheet/pin config avail? where i can see what is connected/used?


#7

At the moment we don’t have datasheets for our add-on boards since we expect most people will just plonk them right on the Pi, but as Gordon suggests it’s really simple to dig into the library and find which pins are used for what.

Some pins you can re-assign reasonably easily ( the Joystick, and the Register Select pin for the LCD ). If you’re both significantly determined and willing to accept a drop in performance you can also theoretically re-assign the i2c and SPI pins by doing them entirely in software.

In both instances, though, you need to make changes to the library- so it’s probably easier to pick pins which don’t conflict with what Dot3k is using in the first place. Delve into the code and you’ll find out what these pins are.


#8

I have the exact same need as @terriblez here. My project (mentionned in other post) is to plug RPI with HifiBerry Amp+ and Dot3K Hat. I’m trying to figure out which PINS are need for both AMP+ and DOT3K because I will obviously not be able to plug directly these two “hats”, i will need to break out the PINS and plug via wire each needed pin for each device.

I’ve been able to identify exactly which are the needed pin I need to connect between RPI and HBAmp+ but I’m totally unable to do so for RPI-DOT3K connection… don’t know why.

In case someone need it, here are the needed pin to connect RPI - HiFiBerry Amp+ Together:

Pin N°: 3, 4, 5, 6, 12, 35, 38, 40.

You need 8 wires for the connexion.

Can you give me the list of PINS i need for the RPI/DOT3K connection? (would be great to precise the PINS for the Joystick too)

Cheers!
Benjamin


#9

I’ve made a lot of test and finally found the answer. I’m sharing!


#10

Nice work! Incidentally I’m actually in the middle of a very drawn out project ( I have so much other stuff to do it gets very little attention! ) to update Pinout with board compatibility functionality so it can produce visualizations similar to yours.

I’m guessing HIFIBerry uses the I2C pins ( the pins in red ) as I2C too, so these boards will work together?

It’s actually not only possible, but pretty straight forward to get DoT3K working with a USB remote, so you could probably ignore the joystick and go wireless instead.


#11

Yes i forgot to put the caption for the RED Pins. Yes it does work together. You need to connect GPIO 3 and 5 to both HifiBerry Amp+ and Dot3K and it does work together. I plugged these via a breadboard to test it.

This was a mess but it worked :-)





#12

Wonderfull, Thanks for sharing benjamin!


#13

This is my planed setup; Pi + hifiberry + dot3k so what you are saying is i can put a stacking header in the hifiberry plug the dot3k on top and all will work?


#14

Yes, I believe it would work… apparently the HifiBerry is using i2c for configuration and I can’t find details on what happens there, but it’s unlikely to be a problem.