From 03188cd333d38f396cb304c42d610a9ea7e720f3 Mon Sep 17 00:00:00 2001
From: Raphael Coeffic <raphael.coeffic@frafos.com>
Date: Sun, 3 Oct 2021 14:51:46 +0200
Subject: [PATCH] [t18/tx18s] add some delay after turning the internal module
 on

This allows to avoid power supply instabilities.

Resolves #802
---
 radio/src/targets/horus/board.h | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/radio/src/targets/horus/board.h b/radio/src/targets/horus/board.h
index c41ff0fc9..ca8839f80 100644
--- a/radio/src/targets/horus/board.h
+++ b/radio/src/targets/horus/board.h
@@ -146,7 +146,26 @@ uint32_t isBootloaderStart(const uint8_t * buffer);
 void SDRAM_Init();
 
 // Pulses driver
-#define INTERNAL_MODULE_ON()           GPIO_SetBits(INTMODULE_PWR_GPIO, INTMODULE_PWR_GPIO_PIN)
+#if defined(RADIO_T18)
+
+// TX18S Workaround (see https://github.com/EdgeTX/edgetx/issues/802):
+//   Add some delay after turning the internal module ON
+//   on the T18 / TX18S, as the latter seems to have issues
+//   with power supply showing instability
+//
+#define INTERNAL_MODULE_ON()                                  \
+  do {                                                        \
+    GPIO_SetBits(INTMODULE_PWR_GPIO, INTMODULE_PWR_GPIO_PIN); \
+    delay_ms(1);                                              \
+  } while (0)
+
+#else
+
+// Just turn the modue ON for all other targets
+#define INTERNAL_MODULE_ON() \
+  GPIO_SetBits(INTMODULE_PWR_GPIO, INTMODULE_PWR_GPIO_PIN)
+
+#endif
 
 #if defined(INTERNAL_MODULE_PXX1) || defined(INTERNAL_MODULE_PXX2)
   #define HARDWARE_INTERNAL_RAS