SPIDrv improved waitForSlaveReady function

fixed beahviour of waitForSlaveReady: now watchdog timeout is calculated
correctly. A timeout is added for the readiness call, that is defaulted
to 0 (no timeout).

Author: andreagilardoni

src/utility/spi_drv.cpp

@@ -215,13 +215,16 @@ void SpiDrv::waitForSlaveSign()
 	while (!waitSlaveSign());
 }
 
-void SpiDrv::waitForSlaveReady()
+void SpiDrv::waitForSlaveReady(unsigned long timeout = 0)
 {
     unsigned long const start = millis();
-	while (!waitSlaveReady())
-    {
-        if ((millis() - start) < 10000) {
+    unsigned long const wd_start = millis();
+    constexpr long wd_timeout = 2000;
+
+	while (!waitSlaveReady() && (timeout != 0 || (millis() - start) < timeout)) {
+        if ((millis() - wd_start) < wd_timeout) {
             WiFi.feedWatchdog();
+            start = millis();
         }
     }
 }

src/utility/spi_drv.h

@@ -59,7 +59,7 @@ class SpiDrv
 
     static char spiTransfer(volatile char data);
 
-    static void waitForSlaveReady();
+    static void waitForSlaveReady(unsigned long timeout = 0); // timeout for wait, 0 means no timeout
 
     //static int waitSpiChar(char waitChar, char* readChar);