From d6af4162cbe426fe39a7918529e531020517b26a Mon Sep 17 00:00:00 2001
From: Jueff <61515422+Jueff@users.noreply.github.com>
Date: Sat, 9 Apr 2022 11:14:22 +0200
Subject: [PATCH] fix ESP32 crash when using SoftwareSerial as transmitter only
 (RxPin=-1) (#235)

---
 src/SoftwareSerial.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/SoftwareSerial.cpp b/src/SoftwareSerial.cpp
index 2acb55c..a83f590 100644
--- a/src/SoftwareSerial.cpp
+++ b/src/SoftwareSerial.cpp
@@ -90,10 +90,10 @@ bool SoftwareSerial::isValidGPIOpin(int8_t pin) {
     // Pinout    https://docs.espressif.com/projects/esp-idf/en/latest/esp32c3/_images/esp32-c3-devkitm-1-v1-pinout.jpg
     return (pin >= 0 && pin <= 1) || (pin >= 3 && pin <= 7) || (pin >= 18 && pin <= 21);
 #else 
-    return true;
+    return pin >= 0;
 #endif
 #else
-    return true;
+    return pin >= 0;
 #endif
 }