From 17e7ee95af10bf3d8ddc43c9921fbcfd27fef74a Mon Sep 17 00:00:00 2001
From: Jaana Burcu Dogan <jbd@google.com>
Date: Wed, 22 Jun 2016 18:48:20 -0700
Subject: [PATCH] fix the representation of the pixel bit

---
 ssd1306/ssd1306.go | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/ssd1306/ssd1306.go b/ssd1306/ssd1306.go
index f98e616..2900cd8 100644
--- a/ssd1306/ssd1306.go
+++ b/ssd1306/ssd1306.go
@@ -104,8 +104,12 @@ func (o *OLED) SetPixel(x, y int, v byte) error {
 	if v > 1 {
 		return fmt.Errorf("value needs to be either 0 or 1; given %v", v)
 	}
-	i := x + (y/8)*o.w + 1
-	o.buf[i] = o.buf[i] | v<<uint((y%8))
+	i := 1 + x + (y/8)*o.w
+	if v == byte(0) {
+		o.buf[i] &= ^(1 << uint((y & 7)))
+	} else {
+		o.buf[i] |= 1 << uint((y & 7))
+	}
 	return nil
 }