From 24e96ba4331f6caa84da5f28b5314a110b6d7025 Mon Sep 17 00:00:00 2001
From: npotts <npotts@users.noreply.github.com>
Date: Sun, 10 Jan 2016 00:23:03 -0700
Subject: [PATCH] 12 bit ADC needs to have initial request bits shifted a bit

---
 convertors/mcp3008/mcp3008.go | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/convertors/mcp3008/mcp3008.go b/convertors/mcp3008/mcp3008.go
index 4d54c8c..9e31575 100644
--- a/convertors/mcp3008/mcp3008.go
+++ b/convertors/mcp3008/mcp3008.go
@@ -38,9 +38,17 @@ const (
 // AnalogValueAt returns the analog value at the given channel of the convertor.
 func (m *MCP3008) AnalogValueAt(chanNum int) (int, error) {
 	var data [3]uint8
-	data[0] = startBit
-	data[1] = uint8(m.Mode)<<7 | uint8(chanNum)<<4
-	data[2] = 0
+	switch m.Bits {
+	case Bits10:
+		data[0] = startBit
+		data[1] = uint8(m.Mode)<<7 | uint8(chanNum)<<4
+		data[2] = 0
+	case Bits12:
+		//[0x06| (channel >> 2), channel << 6, 0]
+		data[0] = 0x06 | (uint8(chanNum) >> 2)
+		data[1] = uint8(chanNum) << 6
+		data[2] = 0
+	}
 
 	glog.V(2).Infof("mcp3008: sendingdata buffer %v", data)
 	if err := m.Bus.TransferAndReceiveData(data[:]); err != nil {