From a07247be87a77b6cc2f90c71b371bbf60766ef26 Mon Sep 17 00:00:00 2001
From: Daniel Friesel <derf@finalrewind.org>
Date: Mon, 18 Apr 2022 18:11:25 +0200
Subject: initial commit

---
 pm1006.lua | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 pm1006.lua

(limited to 'pm1006.lua')

diff --git a/pm1006.lua b/pm1006.lua
new file mode 100644
index 0000000..1aeed17
--- /dev/null
+++ b/pm1006.lua
@@ -0,0 +1,20 @@
+local pm1006 = {}
+
+function pm1006.parse_frame(data)
+	if string.byte(data, 1) ~= 0x16 or string.byte(data, 2) ~= 0x11 or string.byte(data, 3) ~= 0x0b then
+		-- invalid header
+		return nil
+	end
+	local checksum = 0
+	for i = 1, 20 do
+		checksum = (checksum + string.byte(data, i)) % 256
+	end
+	if checksum ~= 0 then
+		-- invalid checksum
+		return nil
+	end
+	local pm2_5 = string.byte(data, 6) * 256 + string.byte(data, 7)
+	return pm2_5
+end
+
+return pm1006
-- 
cgit v1.2.3