From b9195b33bc44e7cea80b140fc6eb6573e77a9451 Mon Sep 17 00:00:00 2001
From: Gregory Ballantine <gballantine@metaunix.net>
Date: Mon, 7 Sep 2026 17:28:34 -0400
Subject: [PATCH] Initial project working with a clock

---
 go.mod  |  7 +++++++
 go.sum  |  6 ++++++
 main.go | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 66 insertions(+), 2 deletions(-)
 create mode 100644 go.sum

diff --git a/go.mod b/go.mod
index 384045d..8962fcf 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,10 @@
 module git.metaunix.net/bitgoblin/pico-time
 
 go 1.25.2
+
+require (
+	tinygo.org/x/drivers v0.36.0
+	tinygo.org/x/tinyfont v0.7.0
+)
+
+require github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 // indirect
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..751d109
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,6 @@
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3pAXIBCelhxNneeOaAeabZDe5s4K6zSpQ=
+tinygo.org/x/drivers v0.36.0 h1:F0x342A6GWqh6abtCa57uAxCyz/b9MbGzvIVvIf+gpE=
+tinygo.org/x/drivers v0.36.0/go.mod h1:DQgKyHkB4G6IEOKVTAjApbKnWGwESN91EVJO+nMOE9Y=
+tinygo.org/x/tinyfont v0.7.0 h1:Ju901eGRThlHLoti9K7myMYyv4phd3I0DrJwc14NTTU=
+tinygo.org/x/tinyfont v0.7.0/go.mod h1:onflMSkpWl7r7j4MIqhPEVV39pn7yL4N3MOePl3G+G8=
diff --git a/main.go b/main.go
index abdb897..6852fd5 100644
--- a/main.go
+++ b/main.go
@@ -1,9 +1,60 @@
 package main
 
 import (
-  "fmt"
+	"fmt"
+	"image/color"
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/ssd1306"
+	"tinygo.org/x/tinyfont"
+	"tinygo.org/x/tinyfont/proggy"
+  "tinygo.org/x/tinyfont/freemono"
+)
+
+var (
+	white = color.RGBA{R: 255, G: 255, B: 255, A: 255}
+	black = color.RGBA{R: 0, G: 0, B: 0, A: 255}
 )
 
 func main() {
-  fmt.Println("Hello there.")
+	// Configure I2C0 using GP4 (SDA) and GP5 (SCL) at 400kHz
+	machine.I2C0.Configure(machine.I2CConfig{
+		Frequency: 400 * machine.KHz,
+    SDA:       machine.GP16,
+    SCL:       machine.GP17,
+	})
+
+	// Initialize the display (default I2C address for SSD1306 is usually 0x3C)
+	display := ssd1306.NewI2C(machine.I2C0)
+	display.Configure(ssd1306.Config{
+		Address: 0x3C,
+		Width:   128,
+		Height:  64,
+	})
+
+	display.ClearDisplay()
+
+	// Base time for clock tracking (update to current time or set via NTP)
+	currentTime := time.Date(2026, time.September, 7, 12, 0, 0, 0, time.UTC)
+	ticker := time.NewTicker(1 * time.Second)
+
+	for range ticker.C {
+		currentTime = currentTime.Add(1 * time.Second)
+
+		// Format time and date strings
+		timeStr := fmt.Sprintf("%02d:%02d:%02d", currentTime.Hour(), currentTime.Minute(), currentTime.Second())
+		dateStr := currentTime.Format("Mon, Jan 02 2006")
+
+		// Clear screen buffer
+		display.ClearBuffer()
+
+		// Render text to display buffer:
+		// WriteLine(target, font, x, y, text, color)
+		tinyfont.WriteLine(display, &proggy.TinySZ8pt7b, 16, 14, dateStr, white)
+		tinyfont.WriteLine(display, &freemono.Bold12pt7b, 6, 44, timeStr, white)
+
+		// Push frame buffer to the OLED panel
+		display.Display()
+	}
 }