diff --git a/examples/ad770x/Makefile b/examples/ad770x/Makefile
new file mode 100644
index 0000000..f102848
--- /dev/null
+++ b/examples/ad770x/Makefile
@@ -0,0 +1,4 @@
+PROGRAM = ad770x
+EXTRA_COMPONENTS = extras/ad770x
+#ESPBAUD = 460800
+include ../../common.mk
diff --git a/examples/ad770x/main.c b/examples/ad770x/main.c
new file mode 100644
index 0000000..6b13afc
--- /dev/null
+++ b/examples/ad770x/main.c
@@ -0,0 +1,50 @@
+/*
+ * Example of using AD7705/AD7706 driver
+ *
+ * Part of esp-open-rtos
+ * Copyright (C) 2017 Ruslan V. Uss <unclerus@gmail.com>
+ * BSD Licensed as described in the file LICENSE
+ */
+#include <esp/uart.h>
+#include <espressif/esp_common.h>
+#include <stdio.h>
+#include <i2c/i2c.h>
+#include <ad770x/ad770x.h>
+#include <FreeRTOS.h>
+#include <task.h>
+
+#define CS_PIN 2
+#define AIN_CHANNEL 0 // AIN1+,AIN1- for AD7705
+
+static const ad770x_params_t dev = {
+ .cs_pin = CS_PIN,
+ .master_clock = AD770X_MCLK_4_9152MHz, // 4.9152 MHz
+ .bipolar = false, // Unipolar mode
+ .gain = AD770X_GAIN_1, // No gain
+ .update_rate = AD770X_RATE_50 // 50 Hz output update rate
+};
+
+void user_init(void)
+{
+ uart_set_baud(0, 115200);
+ printf("SDK version:%s\n", sdk_system_get_sdk_version());
+
+ while (ad770x_init(&dev, AIN_CHANNEL) != 0)
+ {
+ printf("Cannot initialize AD7705\n");
+ vTaskDelay(500 / portTICK_PERIOD_MS);
+ }
+
+ while (true)
+ {
+ // wait for data
+ while (!ad770x_data_ready(&dev, AIN_CHANNEL)) {}
+
+ // Read result
+ uint16_t raw = ad770x_raw_adc_value(&dev, AIN_CHANNEL);
+
+ printf("Raw ADC value: %d\n", raw);
+
+ vTaskDelay(500 / portTICK_PERIOD_MS);
+ }
+}
diff --git a/extras/ad770x/ad770x.c b/extras/ad770x/ad770x.c
new file mode 100644
index 0000000..9bd8af5
--- /dev/null
+++ b/extras/ad770x/ad770x.c
@@ -0,0 +1,182 @@
+/**
+ * Driver for AD7705/AD7706 SPI ADC
+ *
+ * Part of esp-open-rtos
+ * Copyright (C) 2017 Ruslan V. Uss <unclerus@gmail.com>
+ * BSD Licensed as described in the file LICENSE
+ */
+#include "ad770x.h"
+
+#include <errno.h>
+#include <esp/gpio.h>
+#include <esp/spi.h>
+#include <espressif/esp_common.h>
+
+#define AD770X_DEBUG
+
+#define BUS 1
+#define INIT_TIMEOUT 500000 // 500ms
+
+#ifdef AD770X_DEBUG
+#include <stdio.h>
+#define debug(fmt, ...) printf("%s" fmt "\n", "AD770x: ", ## __VA_ARGS__)
+#else
+#define debug(fmt, ...)
+#endif
+
+#define timeout_expired(start, len) ((uint32_t)(sdk_system_get_time() - (start)) >= (len))
+
+#define _BV(x) (1 << (x))
+
+#define REG_COMM 0x00 // 8 bits
+#define REG_SETUP 0x01 // 8 bits
+#define REG_CLOCK 0x02 // 8 bits
+#define REG_DATA 0x03 // 16 bits
+#define REG_TEST 0x04 // 8 bits
+#define REG_OFFS 0x06 // 24 bits
+#define REG_GAIN 0x07 // 24 bits
+
+#define BIT_COMM_CH0 0
+#define BIT_COMM_CH1 1
+#define BIT_COMM_STBY 2
+#define BIT_COMM_RW 3
+#define BIT_COMM_RS0 4
+#define BIT_COMM_RS1 5
+#define BIT_COMM_RS2 6
+#define BIT_COMM_DRDY 7
+
+#define MASK_COMM_CH 0x03
+#define MASK_COMM_RS 0x70
+
+#define BIT_CLOCK_FS0 0
+#define BIT_CLOCK_FS1 1
+#define BIT_CLOCK_CLK 2
+#define BIT_CLOCK_CLKDIV 3
+#define BIT_CLOCK_CLKDIS 4
+
+#define MASK_CLOCK_FS 0x03
+#define MASK_CLOCK_CLK 0x0c
+
+#define BIT_SETUP_FSYNC 0
+#define BIT_SETUP_BUF 1
+#define BIT_SETUP_BU 2
+#define BIT_SETUP_G0 3
+#define BIT_SETUP_G1 4
+#define BIT_SETUP_G2 5
+#define BIT_SETUP_MD0 6
+#define BIT_SETUP_MD1 7
+
+#define MASK_SETUP_GAIN 0x38
+#define MASK_SETUP_MODE 0xc0
+
+static const spi_settings_t config = {
+ .endianness = SPI_BIG_ENDIAN,
+ .msb = true,
+ .minimal_pins = true,
+ .mode = SPI_MODE3,
+ .freq_divider = SPI_FREQ_DIV_500K
+};
+
+static uint8_t write(uint8_t cs_pin, uint8_t value)
+{
+ spi_settings_t old;
+ spi_get_settings(BUS, &old);
+ spi_set_settings(BUS, &config);
+
+ gpio_write(cs_pin, false);
+ uint8_t res = spi_transfer_8(BUS, value);
+ //debug("byte wr: 0x%02x", value);
+ gpio_write(cs_pin, true);
+
+ spi_set_settings(BUS, &old);
+ return res;
+}
+
+inline static uint8_t read_byte(uint8_t cs_pin)
+{
+ return write(cs_pin, 0);
+}
+
+static uint16_t read_word(uint8_t cs_pin)
+{
+ spi_settings_t old;
+ spi_get_settings(BUS, &old);
+ spi_set_settings(BUS, &config);
+
+ gpio_write(cs_pin, false);
+ uint16_t res = spi_transfer_16(BUS, 0);
+ gpio_write(cs_pin, true);
+
+ spi_set_settings(BUS, &old);
+ return res;
+}
+
+static void prepare(uint8_t channel, uint8_t reg, bool read, uint8_t cs_pin, bool standby)
+{
+ write(cs_pin,
+ (channel & MASK_COMM_CH) |
+ (read ? _BV(BIT_COMM_RW) : 0) |
+ ((reg << BIT_COMM_RS0) & MASK_COMM_RS) |
+ (standby ? _BV(BIT_COMM_STBY) : 0)
+ );
+}
+
+int ad770x_init(const ad770x_params_t *params, uint8_t channel)
+{
+ if (!spi_set_settings(BUS, &config))
+ {
+ debug("Cannot init SPI");
+ return -EIO;
+ }
+
+ if ((params->master_clock >= AD770X_MCLK_2_4576MHz && params->update_rate < AD770X_RATE_50)
+ || (params->master_clock < AD770X_MCLK_2_4576MHz && params->update_rate > AD770X_RATE_200))
+ {
+ debug("Invalid update rate / master clock combination");
+ return -EINVAL;
+ }
+
+ gpio_enable(params->cs_pin, GPIO_OUTPUT);
+ gpio_write(params->cs_pin, true);
+
+ prepare(channel, REG_CLOCK, false, params->cs_pin, false);
+ write(params->cs_pin,
+ ((params->master_clock << BIT_CLOCK_CLK) & MASK_CLOCK_CLK) |
+ (params->update_rate & MASK_CLOCK_FS)
+ );
+
+ ad770x_set_mode(params, channel, AD770X_MODE_CALIBRATION);
+
+ uint32_t start = sdk_system_get_time();
+ while (!ad770x_data_ready(params, channel))
+ if (timeout_expired(start, INIT_TIMEOUT))
+ {
+ debug("Timeout while calibration");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+void ad770x_set_mode(const ad770x_params_t *params, uint8_t channel, ad770x_mode_t mode)
+{
+ prepare(channel, REG_SETUP, false, params->cs_pin, false);
+ write(params->cs_pin,
+ ((params->gain << BIT_SETUP_G0) & MASK_SETUP_GAIN) |
+ (params->bipolar ? 0 : _BV(BIT_SETUP_BU)) |
+ ((mode << BIT_SETUP_MD0) & MASK_SETUP_MODE)
+ );
+}
+
+bool ad770x_data_ready(const ad770x_params_t *params, uint8_t channel)
+{
+ prepare(channel, REG_COMM, true, params->cs_pin, false);
+ return !(read_byte(params->cs_pin) & _BV(BIT_COMM_DRDY));
+}
+
+uint16_t ad770x_raw_adc_value(const ad770x_params_t *params, uint8_t channel)
+{
+ prepare(channel, REG_DATA, true, params->cs_pin, false);
+ return read_word(params->cs_pin);
+}
+
diff --git a/extras/ad770x/ad770x.h b/extras/ad770x/ad770x.h
new file mode 100644
index 0000000..bfa2a98
--- /dev/null
+++ b/extras/ad770x/ad770x.h
@@ -0,0 +1,118 @@
+/**
+ * Driver for AD7705/AD7706 SPI ADC
+ *
+ * Part of esp-open-rtos
+ * Copyright (C) 2017 Ruslan V. Uss <unclerus@gmail.com>
+ * BSD Licensed as described in the file LICENSE
+ */
+#ifndef _EXTRAS_AD770X_H_
+#define _EXTRAS_AD770X_H_
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Input gain
+ */
+typedef enum
+{
+ AD770X_GAIN_1 = 0,
+ AD770X_GAIN_2,
+ AD770X_GAIN_4,
+ AD770X_GAIN_8,
+ AD770X_GAIN_16,
+ AD770X_GAIN_32,
+ AD770X_GAIN_64,
+ AD770X_GAIN_128
+} ad770x_gain_t;
+
+/**
+ * Master clock frequency
+ */
+typedef enum
+{
+ AD770X_MCLK_1MHz = 0, //!< 1 MHz
+ AD770X_MCLK_2MHz, //!< 2 MHz
+ AD770X_MCLK_2_4576MHz, //!< 2.4576 MHz
+ AD770X_MCLK_4_9152MHz, //!< 4.9152 MHz
+} ad770x_master_clock_t;
+
+/**
+ * Output update rate
+ */
+typedef enum
+{
+ AD770X_RATE_20 = 0, //!< Output update rate is 20 Hz, -3 dB filter cutoff = 5.24 Hz, works with 1 or 2 MHz master clock
+ AD770X_RATE_25, //!< Output update rate is 25 Hz, -3 dB filter cutoff = 6.55 Hz, works with 1 or 2 MHz master clock
+ AD770X_RATE_100, //!< Output update rate is 100 Hz, -3 dB filter cutoff = 26.2 Hz, works with 1 or 2 MHz master clock
+ AD770X_RATE_200, //!< Output update rate is 200 Hz, -3 dB filter cutoff = 52.4 Hz, works with 1 or 2 MHz master clock
+ AD770X_RATE_50, //!< Output update rate is 50 Hz, -3 dB filter cutoff = 13.1 Hz, works with 2.4576 or 4.9152 MHz master clock
+ AD770X_RATE_60, //!< Output update rate is 60 Hz, -3 dB filter cutoff = 15.7 Hz, works with 2.4576 or 4.9152 MHz master clock
+ AD770X_RATE_250, //!< Output update rate is 250 Hz, -3 dB filter cutoff = 65.5 Hz, works with 2.4576 or 4.9152 MHz master clock
+ AD770X_RATE_500, //!< Output update rate is 500 Hz, -3 dB filter cutoff = 131 Hz, works with 2.4576 or 4.9152 MHz master clock
+} ad770x_update_rate_t;
+
+/**
+ * Device mode
+ */
+typedef enum
+{
+ AD770X_MODE_NORMAL = 0,
+ AD770X_MODE_CALIBRATION,
+ AD770X_MODE_ZERO_CALIBRATION,
+ AD770X_MODE_FULL_CALIBRATION
+} ad770x_mode_t;
+
+/**
+ * Device descriptor
+ */
+typedef struct
+{
+ uint8_t cs_pin; //!< GPIO pin for chip select
+ ad770x_master_clock_t master_clock; //!< Master clock frequency
+ bool bipolar; //!< Bipolar/Unipolar mode
+ ad770x_gain_t gain; //!< Input gain
+ ad770x_update_rate_t update_rate; //!< Output update rate
+} ad770x_params_t;
+
+/**
+ * Init device and setup channel params
+ * @param params Device descriptor pointer
+ * @param channel Input channel
+ * @return Non-zero when error occured
+ */
+int ad770x_init(const ad770x_params_t *params, uint8_t channel);
+
+/**
+ * Set device mode (see datasheet)
+ * @param params Device descriptor pointer
+ * @param channel Input channel
+ * @param mode Device mode
+ */
+void ad770x_set_mode(const ad770x_params_t *params, uint8_t channel, ad770x_mode_t mode);
+
+/**
+ * Get conversion status
+ * @param params Device descriptor pointer
+ * @param channel Input channel
+ * @return true when data is ready
+ */
+bool ad770x_data_ready(const ad770x_params_t *params, uint8_t channel);
+
+/**
+ * Get converted ADC value
+ * @param params Device descriptor pointer
+ * @param channel Input channel
+ * @return Raw ADC value
+ */
+uint16_t ad770x_raw_adc_value(const ad770x_params_t *params, uint8_t channel);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _EXTRAS_AD770X_H_ */
diff --git a/extras/ad770x/component.mk b/extras/ad770x/component.mk
new file mode 100644
index 0000000..a4d47f5
--- /dev/null
+++ b/extras/ad770x/component.mk
@@ -0,0 +1,9 @@
+# Component makefile for extras/ad770x (AD7705/AD7706 driver)
+
+# expected anyone using ADC driver includes it as 'ad770x/ad770x.h'
+INC_DIRS += $(ad770x_ROOT)..
+
+# args for passing into compile rule generation
+ad770x_SRC_DIR = $(ad770x_ROOT)
+
+$(eval $(call component_compile_rules,ad770x))