From f7ed7670f375dad093fe7189a76da3fbef2b8061 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Mon, 11 Jul 2022 10:39:09 +0200
Subject: [PATCH] add UART EEPROM

---
 main.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/main.c b/main.c
index 7459ff6..23737d3 100644
--- a/main.c
+++ b/main.c
@@ -40,6 +40,40 @@ static void wait_10us(uint32_t us10)
 	while (us10--); // burn energy
 }
 
+void putc(char c)
+{
+	while (!UART1->SR.fields.TXE); // wait until TX buffer is empty
+	UART1->DR.reg = c; // put character in buffer to be transmitted
+	// don't wait until the transmission is complete
+}
+
+void puts(const char* s)
+{
+	if (NULL == s) {
+		return;
+	}
+	while (*s) {
+		putc(*s++);
+		IWDG_KR = IWDG_KR_KEY_REFRESH; // reset watchdog
+	}
+}
+
+void putn(uint8_t n)
+{
+	n &= 0x0f; // ensure it's a nibble
+	if (n < 0xa) {
+		putc('0' + n);
+	} else {
+		putc('a' + (n - 0x0a));
+	}
+}
+
+void puth(uint8_t h)
+{
+	putn(h >> 4);
+	putn(h & 0x0f);
+}
+
 void main(void)
 {
 	sim(); // disable interrupts (while we reconfigure them)