check the hardware: Vcc to Vcc GND to GND DQ (DATA) to P2.1 resistor (4.7K or 2-6K) from Vcc to P2.1   P2.1 defined in code: #define OWPIN  9 https://github.com/energia/Energia/wiki/Hardware#wiki-LaunchPad_MSP430G2553   pinouts: http://datasheets.maximintegrated.com/en/ds/DS18B20.pdf   Figure 5. Powering the DS18B20 with an External Suppl