From 67f2b3a2979cd01a66b36c1abfea1f2aef47315d Mon Sep 17 00:00:00 2001
From: Birte Kristina Friesel <derf@finalrewind.org>
Date: Sat, 29 Jun 2024 18:48:42 +0200
Subject: hardcode bus_id = 0. It's highly unlikely to change.

---
 scd4x.lua | 36 +++++++++++++++++-------------------
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/scd4x.lua b/scd4x.lua
index 89679c1..18809b2 100644
--- a/scd4x.lua
+++ b/scd4x.lua
@@ -1,41 +1,39 @@
 local scd4x = {}
-local device_address = 0x62
-
-scd4x.bus_id = 0
+local addr = 0x62
 
 function scd4x.start()
-	i2c.start(scd4x.bus_id)
-	if not i2c.address(scd4x.bus_id, device_address, i2c.TRANSMITTER) then
+	i2c.start(0)
+	if not i2c.address(0, addr, i2c.TRANSMITTER) then
 		return false
 	end
-	i2c.write(scd4x.bus_id, {0x21, 0xb1})
-	i2c.stop(scd4x.bus_id)
+	i2c.write(0, {0x21, 0xb1})
+	i2c.stop(0)
 	return true
 end
 
 function scd4x.stop()
-	i2c.start(scd4x.bus_id)
-	if not i2c.address(scd4x.bus_id, device_address, i2c.TRANSMITTER) then
+	i2c.start(0)
+	if not i2c.address(0, addr, i2c.TRANSMITTER) then
 		return false
 	end
-	i2c.write(scd4x.bus_id, {0x3f, 0x86})
-	i2c.stop(scd4x.bus_id)
+	i2c.write(0, {0x3f, 0x86})
+	i2c.stop(0)
 	return true
 end
 
 function scd4x.read()
-	i2c.start(scd4x.bus_id)
-	if not i2c.address(scd4x.bus_id, device_address, i2c.TRANSMITTER) then
+	i2c.start(0)
+	if not i2c.address(0, addr, i2c.TRANSMITTER) then
 		return nil
 	end
-	i2c.write(scd4x.bus_id, {0xec, 0x05})
-	i2c.stop(scd4x.bus_id)
-	i2c.start(scd4x.bus_id)
-	if not i2c.address(scd4x.bus_id, device_address, i2c.RECEIVER) then
+	i2c.write(0, {0xec, 0x05})
+	i2c.stop(0)
+	i2c.start(0)
+	if not i2c.address(0, addr, i2c.RECEIVER) then
 		return nil
 	end
-	local data = i2c.read(scd4x.bus_id, 9)
-	i2c.stop(scd4x.bus_id)
+	local data = i2c.read(0, 9)
+	i2c.stop(0)
 	if not scd4x.crc_valid(data, 9) then
 		return nil
 	end
-- 
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