Factorio Player Health on LED strip

[raid]

Hi there,

I've been enjoying a lot Factorio during the last months, but I've also been busy playing around with my LED strips.
One day I thought, hey, why not combine Factorio with my LEDs
I don't think this really qualifies as a "Mod" because it's kind of more low-level.

So I hacked around a bit and finally got it working, my LED strip can now display the Player Health
In theory, any numerical value from the game is possible to display (also in any color) but I jsut used the player health as a simple example.
In this video I just run into some enemies on an empty map to show that it works: https://www.youtube.com/watch?v=4T1cs6--wXU

Hope you find that as sweet as I do

@Factorio Team: Thanks a LOT for leaving in the symbol names in the Linux binary <3

[Kewlhotrod]

aha this is really sweet, you need to make a power version so when power gets low, disco lights start flashing. maybe add a horn sound too.

[Koub]

This. Is. Genius.

[bobucles]

This is really cool. What programs did you use to get it going?

[AutoMcD]

I know how he did it.

Factorio-> MAGIC ARTIFACT -> external LED interface.

duh. obvious.

[ssilk]

Moved to Show your Creations, but I left a link in General.

I would like to see the code.

[raid]

My initial approach was to convert the number I wanted to get out of the game (player life percent) to a binary representation in Lua and then call a function for every 1 and call a function for every 0.
This gets called every tick.

Code: Select all

...
function pushBits2flashlight(originalInt, bitArray)
	dontcare = game.darkness -- reset signal
	for cnt, bit in ipairs(bitArray) do
		if bit == 0 then
			game.player.disable_flashlight() -- send 0
		elseif bit == 1 then
			game.player.enable_flashlight() -- send 1
		else
			print("pushBits2flashlight: UNEXPECTED VALUE IN bitArray")
		end
	end
end
...

I would then run Factorio in GDB to register hooks when the breakpoint of the Lua function in the binary was hit. This example is valid for Factorio 0.12.33.

Code: Select all

break _ZN13LuaGameScript15luaReadDarknessEP9lua_State
commands
silent
shell /usr/local/bin/factorioHook r
continue
end

break _ZN10LuaControl20luaDisableFlashlightEP9lua_State
commands
silent
shell /usr/local/bin/factorioHook 0
continue
end

break _ZN10LuaControl19luaEnableFlashLightEP9lua_State
commands
silent
shell /usr/local/bin/factorioHook 1
continue
end

run

/usr/local/bin/factorioHook was just a shell script that wrote to a FIFO in /tmp that was created with a C program that was running as a local daemon.
This program would read the value from the FIFO, reassemble the Integer and then send it via UDP to the Raspberry Pi over UDP.

Code: Select all

...
	for (;;) {
		fifo = open(fifoNAME, O_RDONLY);
		bytes = read(fifo, buf, 1);
		close(fifo);

		printf("Received (%d bytes): %s \n", bytes, buf);
		if ( buf[0] == 'r' ) {
			printf("RESET SIGNAL!\n");
			i=0;
			continue;
		}
		else if ( buf[0] != '0' && buf[0] != '1' ) {
			printf("GOT FUCKED UP VALUE!\n");
			continue;
		}
		strncpy(&intAssembling[i], buf, 1);
		i++;
		if (i >= 8) {
			assembled = assembleINT(intAssembling);
			// put tha shit on the wire
			sprintf(udpBUF, "%d", assembled);
			printf("Sending %d to Raspi!\n", assembled);
			sendto(socke, udpBUF, strlen(udpBUF)/*+1*/, 0, (struct sockaddr*) &dest, (socklen_t) sizeof(struct sockaddr_in));
			i = 0;
		}
	}
...

The Raspberry Pi was just running a trivial UDP server to listen for the value to display.

Code: Select all

...
	def percent2strip(self, percent, col):
		"""Light up 'percent' percent of the strip.
		   This value is between 0 and 100."""
		leds2light = int(float(NUMBER_OF_PIXELS) * (float(percent)/100)) # calculate how many LEDs to light
		print "Will light %d of %d LEDs (%d%%)" % (leds2light, NUMBER_OF_PIXELS, percent)
		self.ledpixels = [color(0,0,0)]*(NUMBER_OF_PIXELS-leds2light) + [col]*leds2light
		self.writeStrip(self.ledpixels)
...

This was a lot of nasty hacking, a lot too much because the game was lagging at 12 FPS on my new Laptop.
The next thing I found out after registering hooks on breakpoints for the Factorio binary was that game.write_file() exists xD
This made it far easier because now all I needed to do was write the Integer value to a file in the script-output/ folder and read that file from my local C daemon, no binary calculation, GDB debugging or FIFO required anymore; it also runs at 60 FPS now ^^
In the end I did a lot of redudant work but still learned a lot about debugging and Linux binary formats as well as 64 Linux calling conventions (my very first approach was to rewrite the functions for the Lua functions in the Linux binary...^^).
But now it works and I can finally put my LED strip to good use.
Maybe I will clean up the source code and release it so everyone with Raspberry Pi and a WS2801 LED strip can use it (also not using GDB anymore improved the practicability by a great bit).

[geekthing]

This is AWESOME!!

How about arduino? Rasberi Pi seems like overkill.

[siggboy]

I love this.

@Factorio Team: Thanks a LOT for leaving in the symbol names in the Linux binary <3

Probably you've just reminded them to invoke "strip" in their build script for release builds
Enjoy it while you can, I'd say, hehe.

[Lingrab]

Awsome. you could use an Arduino and try and create a supplementary control panel using that can switch weapons and fire the weapon

[kovarex]

This is way too complicated. Do you know that you can just output text into a file?

[Nexela]

This is way too complicated. Do you know that you can just output text into a file?

This was a lot of nasty hacking, a lot too much because the game was lagging at 12 FPS on my new Laptop.
The next thing I found out after registering hooks on breakpoints for the Factorio binary was that game.write_file() exists xD
This made it far easier because now all I needed to do was write the Integer value to a file in the script-output/ folder and read that file from my local C daemon, no binary calculation, GDB debugging or FIFO required anymore; it also runs at 60 FPS now ^^

[nr2117]

I'm seriously considering getting that WS2801 or similar blinkenlights LED strip now and using a r-pi.

I know nothing about modding but I've been meaning to get a R-Pi with a DAC for a while now for another project, but this had added to my reasons to get it.

What's the output/where is it being read?

Damn, there's a lot of possibilities for this. I'm guessing there's another output for player movement. I'd like to animate that strip somehow, even if it's just random lights flashing.