diff --git a/OneWire.h b/OneWire.h
index d8513e6..f344158 100644
--- a/OneWire.h
+++ b/OneWire.h
@@ -126,6 +126,17 @@
 #define DIRECT_WRITE_LOW(base, mask)    (GPOC = (mask))             //GPIO_OUT_W1TC_ADDRESS
 #define DIRECT_WRITE_HIGH(base, mask)   (GPOS = (mask))             //GPIO_OUT_W1TS_ADDRESS
 
+#elif defined(RBL_NRF51822)
+#define PIN_TO_BASEREG(pin)             (0)
+#define PIN_TO_BITMASK(pin)             (pin)
+#define IO_REG_TYPE uint32_t
+#define IO_REG_ASM
+#define DIRECT_READ(base, pin)          nrf_gpio_pin_read(pin)
+#define DIRECT_WRITE_LOW(base, pin)     nrf_gpio_pin_clear(pin)
+#define DIRECT_WRITE_HIGH(base, pin)    nrf_gpio_pin_set(pin)
+#define DIRECT_MODE_INPUT(base, pin)    nrf_gpio_cfg_input(pin, NRF_GPIO_PIN_NOPULL)
+#define DIRECT_MODE_OUTPUT(base, pin)   nrf_gpio_cfg_output(pin)
+
 #else
 #define PIN_TO_BASEREG(pin)             (0)
 #define PIN_TO_BITMASK(pin)             (pin)