Update README.md

README.md

@@ -33,7 +33,7 @@ All work was done on ESP32-WROOM with custom made LoRa shield, if your ESP32 boa
   - lora output power **CfgPower**, 20 (max 20 dBm ~ 100mW, change to lower value if needed)
   - sync word **CfgSync**, 0xf3
 - consider minimum decode level based on on BW + SF ![alt text](images/bandwidth_vs_sf.jpg)
-- use 80 MHz ESP32 frequency in Arduino, it will prolong battery life when operating portable, higher CPU speed is not required, there are no CPU intensive operations
+- use 80 MHz ESP32 frequency in Arduino SDK, it will prolong battery life when operating portable, higher CPU speed is not required, there are no CPU intensive operations
 - uses LoRa **built-in checksum** calculation to drop broken packets
 - note, that there a is **significant frequency drift** on temperature changes for different modules
   - you need to use **external TCXO** if you are planning to use modules for narrow bandwidths less than 125 kHz