From 71396e8ff1f92f70bf67584a9b65315229fedfb6 Mon Sep 17 00:00:00 2001
From: Dominic Radermacher <dominic@familie-radermacher.ch>
Date: Sun, 11 Sep 2022 06:29:44 +0200
Subject: [PATCH] change init to first invalidate, then init (maybe needed for
 some ptouch models?)

---
 src/libptouch.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/libptouch.c b/src/libptouch.c
index 415a9ac..917edef 100644
--- a/src/libptouch.c
+++ b/src/libptouch.c
@@ -186,7 +186,11 @@ int ptouch_send(ptouch_dev ptdev, uint8_t *data, size_t len)
 
 int ptouch_init(ptouch_dev ptdev)
 {
-	char cmd[]="\x1b\x40";		/* 1B 40 = ESC @ = INIT */
+	/* first invalidate, then send init command */
+	uint8_t cmd[102];
+	memset(cmd, 0, 100);
+	cmd[100] = 0x1b;	/* ESC */
+	cmd[101] = 0x40;	/* @ */
 	return ptouch_send(ptdev, (uint8_t *)cmd, strlen(cmd));
 }