diff --git a/src/machine/buffer.go b/src/machine/buffer.go
index 1528c25be0..508700d9e9 100644
--- a/src/machine/buffer.go
+++ b/src/machine/buffer.go
@@ -4,8 +4,6 @@ import (
 	"runtime/volatile"
 )
 
-const bufferSize = 128
-
 // RingBuffer is ring buffer implementation inspired by post at
 // https://www.embeddedrelated.com/showthread/comp.arch.embedded/77084-1.php
 type RingBuffer struct {
diff --git a/src/machine/buffer_atmega.go b/src/machine/buffer_atmega.go
new file mode 100644
index 0000000000..a321eaecdf
--- /dev/null
+++ b/src/machine/buffer_atmega.go
@@ -0,0 +1,5 @@
+//go:build atmega
+
+package machine
+
+const bufferSize = 32
diff --git a/src/machine/buffer_generic.go b/src/machine/buffer_generic.go
new file mode 100644
index 0000000000..0d82b44940
--- /dev/null
+++ b/src/machine/buffer_generic.go
@@ -0,0 +1,5 @@
+//go:build !atmega
+
+package machine
+
+const bufferSize = 128