Reduce block size to 8b

src/rx.ino

@@ -16,25 +16,16 @@ void setup()
 
 void loop()
 {
-	uint8_t buf[4];
+	uint8_t buf[2];
+	size_t buf_len = sizeof(buf); // rip
 
-	if (driver.recv(buf, &4)){
-		int buffer = atoi((char*)buf);
-		int channel = buffer%10;
-		int value = buffer/10;
+	if (driver.recv(buf, &buf_len)){
+		uint8_t value = buf[1];
+		uint8_t ch = [buf]2;
 
-		switch(channel){
-			case 0:
-				channel = 3;
-				break;
-			case 1:
-				channel = 5;
-				break;
-			case 2:
-				channel = 6;
-				break;
-		}
+		// 0 -> 3; 1 -> 5; 2 -> 6
+		ch = (ch ? ++ch + 3 : 3);
 
-		analogWrite(channel, value);
+		analogWrite(ch, value);
 	}
 }

src/tx.ino

@@ -4,7 +4,7 @@
 
 RH_ASK driver(2000);
 
-int lastval[] = {0,0,0};
+uint8_t lastval[] = {0,0,0};
 
 void setup()
 {
@@ -14,17 +14,17 @@ void setup()
 
 void loop()
 {
-
-	for(int i=0; i < 3; i++){
-		int val = analogRead(i)/4;
+	for(uint8_t i = 0; i < 3; i++) {
+		uint8_t val = (uint8_t)analogRead(i)/4;
 
 		if(val >= lastval[i]+3 || val <= lastval[i]-3){
-			char msg[4];
-			lastval[i] = val;
-			sprintf(msg, "%d%d", val, i);
+			uint8_t msg[2] = { val, i };
+
 			Serial.println(msg);
-			driver.send((uint8_t *)msg, 4);
+			driver.send((uint8_t *)msg, 2);
 			driver.waitPacketSent();
+
+			lastval[i] = val;
 		}
 	}