From 82c5d97f4ffd601d34db6832ca5a09f0ba7b378a Mon Sep 17 00:00:00 2001
From: fdai7354 <alan.muhemad@informatik.hs-fulda.de>
Date: Sat, 8 Feb 2025 06:09:13 +0100
Subject: [PATCH] Write to the Character Device
---
main.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/main.c b/main.c
index 8c6a45d..61a4033 100644
--- a/main.c
+++ b/main.c
@@ -9,6 +9,8 @@
static const char *PIPE_ONE = "/tmp/pipeOne";
static const char *PIPE_TWO = "/tmp/pipeTwo";
+static const char *CHAR_DEV = "/dev/packet_receiver";
+
int main(void)
{
// mkfifo() nur ausführen, wenn die Pipes noch nicht existieren,
@@ -36,6 +38,16 @@ int main(void)
return 1;
}
+ // Open the char device for writing
+ int fdCharDev = open(CHAR_DEV, O_WRONLY);
+ if (fdCharDev == -1) {
+ perror("open /dev/packet_receiver");
+ close(fdOne);
+ close(fdTwo);
+ return 1;
+ }
+ printf("Opened %s for writing.\n", CHAR_DEV);
+
// Dauerhafte Lese-Schleife
while (1) {
char bufOne[128] = {0};
@@ -91,6 +103,21 @@ int main(void)
break;
}
+ // ========= Write to char device =========
+ // Build a packet string. Adapt SENDER / IDs / values to your needs.
+ // Example: "SENDER=1 VID1=10 VAL1=<temp> VID2=11 VAL2=<freq>"
+ char transmitBuf[256] = {0};
+ snprintf(transmitBuf, sizeof(transmitBuf),
+ "SENDER=1 VID1=10 VAL1=%s VID2=11 VAL2=%s",
+ bufOne, bufTwo);
+
+ ssize_t written = write(fdCharDev, transmitBuf, strlen(transmitBuf));
+ if (written < 0) {
+ perror("write /dev/packet_receiver");
+ } else {
+ printf("Wrote packet to %s: %s\n", CHAR_DEV, transmitBuf);
+ }
+
// Kurze Pause, damit CPU-Last nicht durch
// Dauerschleife hochgetrieben wird
usleep(200000); // 200 ms
--
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