try sleep(1.0)

afsk/main.c

@@ -1406,7 +1406,7 @@ void get_tlm_fox() {
 //      while ((millis() - sampleTime) < (unsigned int)samplePeriod)
      int startSleep = millis();	    
       while ((millis() - sampleTime) < ((unsigned int)frameTime - 500))  // was 100
-        sleep(0.5);  // 25);
+        sleep(1.0); // 0.5);  // 25);
 //        sleep((unsigned int)sleepTime);
 /**/