From 79ab93680cac8d2d930f580a772fb73237a5d742 Mon Sep 17 00:00:00 2001
From: Code1110 <sk@skhome.ch>
Date: Mon, 7 Nov 2016 23:29:03 +0100
Subject: [PATCH] Added support for 7-segment displays

---
 font7seg.lua | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 max7219.lua  | 41 +++++++++++++++++++++++++++
 2 files changed, 121 insertions(+)
 create mode 100644 font7seg.lua

diff --git a/font7seg.lua b/font7seg.lua
new file mode 100644
index 0000000..09b0aae
--- /dev/null
+++ b/font7seg.lua
@@ -0,0 +1,80 @@
+local modname = ...
+local M = {}
+_G[modname] = M
+
+local digits = {}
+digits[" "] = 0x00
+digits["-"] = 0x01
+digits["_"] = 0x08
+digits["0"] = 0x7e
+digits["1"] = 0x30
+digits["2"] = 0x6d
+digits["3"] = 0x79
+digits["4"] = 0x33
+digits["5"] = 0x5b
+digits["6"] = 0x5f
+digits["7"] = 0x70
+digits["8"] = 0x7f
+digits["9"] = 0x7b
+digits["a"] = 0x7d
+digits["b"] = 0x1f
+digits["c"] = 0x0d
+digits["d"] = 0x3d
+digits["e"] = 0x6f
+digits["f"] = 0x47
+digits["g"] = 0x7b
+digits["h"] = 0x17
+digits["i"] = 0x10
+digits["j"] = 0x18
+--digits["k"] = 0x08 -- not supported
+digits["l"] = 0x06
+--digits["m"] = 0x08 -- not supported
+digits["n"] = 0x15
+digits["o"] = 0x1d
+digits["p"] = 0x67
+digits["q"] = 0x73
+digits["r"] = 0x05
+digits["s"] = 0x5b
+digits["t"] = 0x0f
+digits["u"] = 0x1c
+digits["v"] = 0x1c
+--digits["w"] = 0x08 -- not supported
+--digits["x"] = 0x08 -- not supported
+digits["y"] = 0x3b
+digits["z"] = 0x6d
+digits["A"] = 0x77
+digits["B"] = 0x7f
+digits["C"] = 0x4e
+digits["D"] = 0x7e
+digits["E"] = 0x4f
+digits["F"] = 0x47
+digits["G"] = 0x5e
+digits["H"] = 0x37
+digits["I"] = 0x30
+digits["J"] = 0x38
+--digits["K"] = 0x08 -- not supported
+digits["L"] = 0x0e
+--digits["M"] = 0x08 -- not supported
+digits["N"] = 0x76
+digits["O"] = 0x7e
+digits["P"] = 0x67
+digits["Q"] = 0x73
+digits["R"] = 0x46
+digits["S"] = 0x5b
+digits["T"] = 0x0f
+digits["U"] = 0x3e
+digits["V"] = 0x3e
+--digits["W"] = 0x08 -- not supported
+--digits["X"] = 0x08 -- not supported
+digits["Y"] = 0x3b
+digits["Z"] = 0x6d
+digits[","] = 0x80
+digits["."] = 0x80
+digits["�"] = 0x63
+
+function M.GetChar(char)
+		local r = digits[char]
+		if (r == nil) then return digits["_"] else return r end
+end
+
+return M
\ No newline at end of file
diff --git a/max7219.lua b/max7219.lua
index 0ef3471..1f9c0bd 100644
--- a/max7219.lua
+++ b/max7219.lua
@@ -240,6 +240,8 @@ function M.setIntensity(intensity)
   end
 end
 
+-- Turns the display on or off.
+-- shutdown: true=turn off, false=turn on
 function M.shutdown(shutdown)
 	local MAX7219_REG_SHUTDOWN = 0x0C
 	
@@ -253,4 +255,43 @@ function M.shutdown(shutdown)
 end
 
 
+function M.write7segment(text)
+    local tab = {}
+
+    local lenNoDots = text:gsub("%.", ""):len()
+    
+    -- pad with spaces to turn off not required digits
+    if (lenNoDots < (8 * numberOfModules)) then
+    	text = text .. string.rep(" ", (8 * numberOfModules) - lenNoDots)
+    end
+    
+    local wasdot = false
+    
+    local font7seg = require("font7seg")
+    
+    for i=string.len(text), 1, -1 do
+    		
+    		local currentChar = text:sub(i,i)
+    		
+    		if (currentChar == ".") then
+    			wasdot = true
+    		else
+	    		if (wasdot) then
+	    			wasdot = false
+	    			-- take care of the decimal point
+	    			table.insert(tab, font7seg.GetChar(currentChar) + 0x80)
+	    		else
+	    			table.insert(tab, font7seg.GetChar(currentChar))
+	    		end    		
+    		end
+    end
+    
+    package.loaded[font7seg] = nil
+		_G[font7seg] = nil
+    font7seg = nil
+    
+		-- todo 1 table per module is required
+    max7219.write( { tab } , { invert = false })
+end
+
 return M