From c98d41fd0a7e451ec1f9b275abcda6e15a5f52c6 Mon Sep 17 00:00:00 2001
From: Brendan <2bndy5@gmail.com>
Date: Wed, 4 Dec 2024 06:12:40 -0800
Subject: [PATCH] fixes for STM32 (#1011)

resolves #1010
* compute `F_CPU` at runtime for STM32 in `startWrite()`
* fix scanner examples `min()`/`max()` calls
---
 RF24.cpp                                   | 5 +++++
 examples/scanner/scanner.ino               | 4 ++--
 examples/scannerGraphic/scannerGraphic.ino | 2 +-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/RF24.cpp b/RF24.cpp
index f0f7a0879..8c2bb77ac 100644
--- a/RF24.cpp
+++ b/RF24.cpp
@@ -1368,6 +1368,11 @@ bool RF24::startWrite(const void* buf, uint8_t len, const bool multicast)
     ce(HIGH);
 #if !defined(F_CPU) || F_CPU > 20000000
     delayMicroseconds(10);
+#endif
+#ifdef ARDUINO_ARCH_STM32
+    if (F_CPU > 20000000) {
+        delayMicroseconds(10);
+    }
 #endif
     ce(LOW);
     return !(status & _BV(TX_FULL));
diff --git a/examples/scanner/scanner.ino b/examples/scanner/scanner.ino
index c8b800931..d6c7d4413 100644
--- a/examples/scanner/scanner.ino
+++ b/examples/scanner/scanner.ino
@@ -141,7 +141,7 @@ void loop(void) {
   if (Serial.available()) {
     int8_t c = Serial.parseInt();
     if (c >= 0) {
-      c = min(125, max(0, c));  // clamp channel to supported range
+      c = min((int8_t)125, c);  // clamp channel to supported range
       constCarrierMode = 1;
       radio.stopListening();
       delay(2);
@@ -199,7 +199,7 @@ void loop(void) {
     // Print out channel measurements, clamped to a single hex digit
     for (int i = 0; i < num_channels; ++i) {
       if (values[i])
-        Serial.print(min(0xf, values[i]), HEX);
+        Serial.print(min((uint8_t)0xf, values[i]), HEX);
       else
         Serial.print(F("-"));
     }
diff --git a/examples/scannerGraphic/scannerGraphic.ino b/examples/scannerGraphic/scannerGraphic.ino
index e11ef6ea3..ddbed5a1b 100644
--- a/examples/scannerGraphic/scannerGraphic.ino
+++ b/examples/scannerGraphic/scannerGraphic.ino
@@ -89,7 +89,7 @@ struct ChannelHistory {
       sum += history[i];
     }
     history[cacheMax - 1] = value;
-    maxPeak = max(sum * 2, maxPeak);  // sum * 2 to allow half-step decay
+    maxPeak = max((uint8_t)(sum * 2), maxPeak);  // sum * 2 to allow half-step decay
     return sum;
   }