From fb2dda3fb3b0e866e3d356882fafc34a6e73abdd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Thu, 13 Oct 2022 13:03:51 +0200
Subject: [PATCH] add UART transmit command

---
 main.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/main.c b/main.c
index f9f6090..586a7a4 100644
--- a/main.c
+++ b/main.c
@@ -124,6 +124,20 @@ void puth(uint8_t h)
 	putn(h & 0x0f);
 }
 
+// ASCII to nibble (0xff if invalid)
+static uint8_t a2n(char c)
+{
+	if (c >= '0' && c <= '9') {
+		return c - '0';
+	} else if (c >= 'a' && c <= 'f') {
+		return c - 'a' + 0xa;
+	} else if (c >= 'A' && c <= 'F') {
+		return c - 'A' + 0xa;
+	} else {
+		return 0xff;
+	}
+}
+
 // set duty cycle of red LED
 void led_red(uint16_t bightness)
 {
@@ -433,6 +447,23 @@ void main(void)
 		if (uart_c) { // data received over UART
 			putc(uart_c); // echo back
 			if ('\r' == uart_c || '\n' == uart_c) { // end of line received
+				if (uart_used >= 9 && 'T' == uart_cmd[0]) { // transmit command
+					bool code_valid = true; // verify it it's really a hex string
+					uint32_t code = 0; // parsed code
+					for (uint8_t i = 0; i < 8; i++) {
+						uint32_t n = a2n(uart_cmd[1 + i]);
+						if (n > 0xf) {
+							code_valid = false;
+							break;
+						} else {
+							code |= (n << (i * 4));
+						}
+					}
+					if (code_valid) {
+						nec_transmit(code); // transmit code
+						puts("\r\ncode transmitted\r\n");
+					}
+				}
 				uart_used = 0; // reset buffer
 			} else if (uart_used < ARRAY_LENGTH(uart_cmd)) {
 				uart_cmd[uart_used++] = uart_c;