diff --git a/cpu/nrf51/periph/adc.c b/cpu/nrf51/periph/adc.c
index 263c7a416..6b6080b0f 100644
--- a/cpu/nrf51/periph/adc.c
+++ b/cpu/nrf51/periph/adc.c
@@ -1,10 +1,10 @@
 /*
- * Copyright (C) 2014 Freie Universität Berlin
- * Copyright (C) 2015 Ludwig Knüpfer
+ * Copyright (C) 2014-2016 Freie Universität Berlin
+ *               2015 Ludwig Knüpfer
  *
- * This file is subject to the terms and conditions of the GNU Lesser General
- * Public License v2.1. See the file LICENSE in the top level directory for more
- * details.
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
  */
 
 /**
@@ -12,7 +12,7 @@
  * @{
  *
  * @file
- * @brief       Low-level UART driver implementation
+ * @brief       Low-level ADC driver implementation
  *
  * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
  * @author      Ludwig Knüpfer <ludwig.knuepfer@fu-berlin.de>
@@ -21,114 +21,73 @@
  */
 
 #include "cpu.h"
+#include "mutex.h"
 #include "periph/adc.h"
 #include "periph_conf.h"
 
-/* guard file in case no ADC device is defined */
-#if ADC_NUMOF
+/**
+ * @brief   Load the ADC configuration
+ * @{
+ */
+#ifdef ADC_CONFIG
+static const uint8_t adc_config[] = ADC_CONFIG;
+#else
+static const uint8_t adc_config[] = {};
+#endif
 
-/* save the maximum value configured for the ADC */
-int adc_max_value;
+/**
+ * @brief   Lock to prevent concurrency issues when used from different threads
+ */
+static mutex_t lock;
 
-int adc_init(adc_t dev, adc_precision_t precision)
+static inline void prep(void)
 {
-    /* the NRF51822 only supports one ADC... */
-    if (dev != ADC_0) {
-        return -2;
-    }
-
-    /* power on ADC */
+    mutex_lock(&lock);
     NRF_ADC->POWER = 1;
+    NRF_ADC->ENABLE = 1;
+}
 
-    /* disable ADC interrupts */
-    NRF_ADC->INTENSET = (ADC_INTENSET_END_Disabled << ADC_INTENSET_END_Pos);
+static inline void done(void)
+{
+    NRF_ADC->ENABLE = 0;
+    NRF_ADC->POWER = 0;
+    mutex_unlock(&lock);
+}
 
-    /* configure ADC, set precision, internal reference to VBG */
-    switch (precision) {
-        case ADC_RES_8BIT:
-            adc_max_value = 255;
-            NRF_ADC->CONFIG = (ADC_CONFIG_RES_8bit << ADC_CONFIG_RES_Pos);
-            break;
-        case ADC_RES_10BIT:
-            adc_max_value = 1023;
-            NRF_ADC->CONFIG = (ADC_CONFIG_RES_10bit << ADC_CONFIG_RES_Pos);
-            break;
-        default:
-            NRF_ADC->POWER = 0;
-            return -1;
+int adc_init(adc_t line)
+{
+    if (line >= ADC_NUMOF) {
+        return -1;
     }
-
-    /* select the reference voltage / prescaler */
-    NRF_ADC->CONFIG |= (ADC_CONFIG_EXTREFSEL_None << ADC_CONFIG_EXTREFSEL_Pos);
-    NRF_ADC->CONFIG |= (ADC_CONFIG_REFSEL_VBG << ADC_CONFIG_REFSEL_Pos);
-    NRF_ADC->CONFIG |= (ADC_CONFIG_INPSEL_AnalogInputOneThirdPrescaling << ADC_CONFIG_INPSEL_Pos);
-
-    /* enable the ADC */
-    NRF_ADC->ENABLE = (ADC_ENABLE_ENABLE_Enabled << ADC_ENABLE_ENABLE_Pos);
-
     return 0;
 }
 
-int adc_sample(adc_t dev, int channel)
+int adc_sample(adc_t line, adc_res_t res)
 {
-    if (dev != ADC_0) {
-        return -2;
-    }
+    int val;
 
-    /* set channel */
-    NRF_ADC->CONFIG &= ~(ADC_CONFIG_PSEL_Msk);
-    NRF_ADC->CONFIG |= (ADC_CONFIG_PSEL_Disabled << ADC_CONFIG_PSEL_Pos);
-    switch (channel) {
-        case 0:
-            NRF_ADC->CONFIG |= (ADC_0_CH0 << ADC_CONFIG_PSEL_Pos);
-            break;
-        case 1:
-            NRF_ADC->CONFIG |= (ADC_0_CH1 << ADC_CONFIG_PSEL_Pos);
-            break;
-        case 2:
-            NRF_ADC->CONFIG |= (ADC_0_CH2 << ADC_CONFIG_PSEL_Pos);
-            break;
-        case 3:
-            NRF_ADC->CONFIG |= (ADC_0_CH3 << ADC_CONFIG_PSEL_Pos);
-            break;
-        default:
-            return -1;
+    /* check if resolution is valid */
+    if (res > 2) {
+        return -1;
     }
 
+    /* prepare device */
+    prep();
+
+    /* set resolution, line, and use 1/3 input and ref voltage scaling */
+    NRF_ADC->CONFIG = ((ADC_CONFIG_REFSEL_SupplyOneThirdPrescaling << 5) |
+                       (ADC_CONFIG_INPSEL_AnalogInputOneThirdPrescaling << 2) |
+                       (1 << (adc_config[line] + 8)) |
+                       res);
     /* start conversion */
     NRF_ADC->TASKS_START = 1;
-
     /* wait for conversion to be complete */
-    while (((NRF_ADC->BUSY & ADC_BUSY_BUSY_Msk) >> ADC_BUSY_BUSY_Pos) == ADC_BUSY_BUSY_Busy) {}
-    NRF_ADC->EVENTS_END = 1;
-
-    /* return result */
-    return (int)NRF_ADC->RESULT;
-}
+    while (NRF_ADC->BUSY == 1) {}
+    /* get result */
+    val = (int)NRF_ADC->RESULT;
 
-void adc_poweron(adc_t dev)
-{
-    if (dev == ADC_0) {
-        NRF_ADC->POWER = 1;
-    }
-}
+    /* free device */
+    done();
 
-void adc_poweroff(adc_t dev)
-{
-    if (dev == ADC_0) {
-        NRF_ADC->POWER = 0;
-    }
+    return val;
 }
-
-int adc_map(adc_t dev, int value, int min, int max)
-{
-    return (int)adc_mapf(dev, value, (float)min, (float)max);
-}
-
-float adc_mapf(adc_t dev, int value, float min, float max)
-{
-    (void) dev;
-    return ((max - min) / ((float)adc_max_value)) * value;
-}
-
-#endif /* ADC_NUMOF */
diff --git a/cpu/nrf5x_common/include/periph_cpu.h b/cpu/nrf5x_common/include/periph_cpu.h
index 63b7d4938..d287e0feb 100644
--- a/cpu/nrf5x_common/include/periph_cpu.h
+++ b/cpu/nrf5x_common/include/periph_cpu.h
@@ -77,6 +77,21 @@ typedef enum {
 } gpio_flank_t;
 /** @} */
 
+/**
+ * @brief   Override ADC resolution values
+ * @{
+ */
+#define HAVE_ADC_RES_T
+typedef enum {
+    ADC_RES_6BIT  = 0xf0,   /**< ADC resolution: 6 bit */
+    ADC_RES_8BIT  = 0x00,   /**< ADC resolution: 8 bit */
+    ADC_RES_10BIT = 0x02,   /**< ADC resolution: 10 bit */
+    ADC_RES_12BIT = 0xf1,   /**< ADC resolution: 12 bit */
+    ADC_RES_14BIT = 0xf2,   /**< ADC resolution: 14 bit */
+    ADC_RES_16BIT = 0xf3    /**< ADC resolution: 16 bit */
+} adc_res_t;
+/** @} */
+
 /**
  * @brief   Timer configuration options
  */