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-rw-r--r--app/drivers/sensor/battery/CMakeLists.txt10
-rw-r--r--app/drivers/sensor/battery/Kconfig21
-rw-r--r--app/drivers/sensor/battery/battery_common.c43
-rw-r--r--app/drivers/sensor/battery/battery_common.h21
-rw-r--r--app/drivers/sensor/battery/battery_nrf_vddh.c116
-rw-r--r--app/drivers/sensor/battery/battery_voltage_divider.c193
6 files changed, 404 insertions, 0 deletions
diff --git a/app/drivers/sensor/battery/CMakeLists.txt b/app/drivers/sensor/battery/CMakeLists.txt
new file mode 100644
index 0000000..1203e53
--- /dev/null
+++ b/app/drivers/sensor/battery/CMakeLists.txt
@@ -0,0 +1,10 @@
+# Copyright (c) 2020-2021 The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+zephyr_include_directories(.)
+
+zephyr_library()
+
+zephyr_library_sources(battery_common.c)
+zephyr_library_sources_ifdef(CONFIG_ZMK_BATTERY_NRF_VDDH battery_nrf_vddh.c)
+zephyr_library_sources_ifdef(CONFIG_ZMK_BATTERY_VOLTAGE_DIVIDER battery_voltage_divider.c) \ No newline at end of file
diff --git a/app/drivers/sensor/battery/Kconfig b/app/drivers/sensor/battery/Kconfig
new file mode 100644
index 0000000..fd8cd26
--- /dev/null
+++ b/app/drivers/sensor/battery/Kconfig
@@ -0,0 +1,21 @@
+# Copyright (c) 2020-2021 The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+config ZMK_BATTERY
+ bool "ZMK battery monitoring"
+ help
+ Enable battery monitoring
+
+config ZMK_BATTERY_NRF_VDDH
+ bool "ZMK nRF VDDH battery monitoring"
+ select ADC
+ select ZMK_BATTERY
+ help
+ Enable ZMK nRF VDDH voltage driver for battery monitoring.
+
+config ZMK_BATTERY_VOLTAGE_DIVIDER
+ bool "ZMK battery voltage divider"
+ select ADC
+ select ZMK_BATTERY
+ help
+ Enable ZMK battery voltage divider driver for battery monitoring.
diff --git a/app/drivers/sensor/battery/battery_common.c b/app/drivers/sensor/battery/battery_common.c
new file mode 100644
index 0000000..36e98af
--- /dev/null
+++ b/app/drivers/sensor/battery/battery_common.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2021 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <errno.h>
+#include <drivers/sensor.h>
+
+#include "battery_common.h"
+
+int battery_channel_get(const struct battery_value *value, enum sensor_channel chan,
+ struct sensor_value *val_out) {
+ switch (chan) {
+ case SENSOR_CHAN_GAUGE_VOLTAGE:
+ val_out->val1 = value->millivolts / 1000;
+ val_out->val2 = (value->millivolts % 1000) * 1000U;
+ break;
+
+ case SENSOR_CHAN_GAUGE_STATE_OF_CHARGE:
+ val_out->val1 = value->state_of_charge;
+ val_out->val2 = 0;
+ break;
+
+ default:
+ return -ENOTSUP;
+ }
+
+ return 0;
+}
+
+uint8_t lithium_ion_mv_to_pct(int16_t bat_mv) {
+ // Simple linear approximation of a battery based off adafruit's discharge graph:
+ // https://learn.adafruit.com/li-ion-and-lipoly-batteries/voltages
+
+ if (bat_mv >= 4200) {
+ return 100;
+ } else if (bat_mv <= 3450) {
+ return 0;
+ }
+
+ return bat_mv * 2 / 15 - 459;
+} \ No newline at end of file
diff --git a/app/drivers/sensor/battery/battery_common.h b/app/drivers/sensor/battery/battery_common.h
new file mode 100644
index 0000000..d81c39e
--- /dev/null
+++ b/app/drivers/sensor/battery/battery_common.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2021 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <drivers/sensor.h>
+#include <stdint.h>
+
+struct battery_value {
+ uint16_t adc_raw;
+ uint16_t millivolts;
+ uint8_t state_of_charge;
+};
+
+int battery_channel_get(const struct battery_value *value, enum sensor_channel chan,
+ struct sensor_value *val_out);
+
+uint8_t lithium_ion_mv_to_pct(int16_t bat_mv);
diff --git a/app/drivers/sensor/battery/battery_nrf_vddh.c b/app/drivers/sensor/battery/battery_nrf_vddh.c
new file mode 100644
index 0000000..9089034
--- /dev/null
+++ b/app/drivers/sensor/battery/battery_nrf_vddh.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2021 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * This is a simplified version of battery_voltage_divider.c which always reads
+ * the VDDHDIV5 channel of the &adc node and multiplies it by 5.
+ */
+
+#define DT_DRV_COMPAT zmk_battery_nrf_vddh
+
+#include <device.h>
+#include <devicetree.h>
+#include <drivers/adc.h>
+#include <drivers/sensor.h>
+#include <logging/log.h>
+
+#include "battery_common.h"
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#define VDDHDIV (5)
+
+static const struct device *adc = DEVICE_DT_GET(DT_NODELABEL(adc));
+
+struct vddh_data {
+ struct adc_channel_cfg acc;
+ struct adc_sequence as;
+ struct battery_value value;
+};
+
+static int vddh_sample_fetch(const struct device *dev, enum sensor_channel chan) {
+ // Make sure selected channel is supported
+ if (chan != SENSOR_CHAN_GAUGE_VOLTAGE && chan != SENSOR_CHAN_GAUGE_STATE_OF_CHARGE &&
+ chan != SENSOR_CHAN_ALL) {
+ LOG_DBG("Selected channel is not supported: %d.", chan);
+ return -ENOTSUP;
+ }
+
+ struct vddh_data *drv_data = dev->data;
+ struct adc_sequence *as = &drv_data->as;
+
+ int rc = adc_read(adc, as);
+ as->calibrate = false;
+
+ if (rc != 0) {
+ LOG_ERR("Failed to read ADC: %d", rc);
+ return rc;
+ }
+
+ int32_t val = drv_data->value.adc_raw;
+ rc = adc_raw_to_millivolts(adc_ref_internal(adc), drv_data->acc.gain, as->resolution, &val);
+ if (rc != 0) {
+ LOG_ERR("Failed to convert raw ADC to mV: %d", rc);
+ return rc;
+ }
+
+ drv_data->value.millivolts = val * VDDHDIV;
+ drv_data->value.state_of_charge = lithium_ion_mv_to_pct(drv_data->value.millivolts);
+
+ LOG_DBG("ADC raw %d ~ %d mV => %d%%", drv_data->value.adc_raw, drv_data->value.millivolts,
+ drv_data->value.state_of_charge);
+
+ return rc;
+}
+
+static int vddh_channel_get(const struct device *dev, enum sensor_channel chan,
+ struct sensor_value *val) {
+ struct vddh_data const *drv_data = dev->data;
+ return battery_channel_get(&drv_data->value, chan, val);
+}
+
+static const struct sensor_driver_api vddh_api = {
+ .sample_fetch = vddh_sample_fetch,
+ .channel_get = vddh_channel_get,
+};
+
+static int vddh_init(const struct device *dev) {
+ struct vddh_data *drv_data = dev->data;
+
+ if (!device_is_ready(adc)) {
+ LOG_ERR("ADC device is not ready %s", adc->name);
+ return -ENODEV;
+ }
+
+ drv_data->as = (struct adc_sequence){
+ .channels = BIT(0),
+ .buffer = &drv_data->value.adc_raw,
+ .buffer_size = sizeof(drv_data->value.adc_raw),
+ .oversampling = 4,
+ .calibrate = true,
+ };
+
+#ifdef CONFIG_ADC_NRFX_SAADC
+ drv_data->acc = (struct adc_channel_cfg){
+ .gain = ADC_GAIN_1_5,
+ .reference = ADC_REF_INTERNAL,
+ .acquisition_time = ADC_ACQ_TIME(ADC_ACQ_TIME_MICROSECONDS, 40),
+ .input_positive = SAADC_CH_PSELN_PSELN_VDDHDIV5,
+ };
+
+ drv_data->as.resolution = 12;
+#else
+#error Unsupported ADC
+#endif
+
+ const int rc = adc_channel_setup(adc, &drv_data->acc);
+ LOG_DBG("VDDHDIV5 setup returned %d", rc);
+
+ return rc;
+}
+
+static struct vddh_data vddh_data;
+
+DEVICE_DT_INST_DEFINE(0, &vddh_init, device_pm_control_nop, &vddh_data, NULL, POST_KERNEL,
+ CONFIG_SENSOR_INIT_PRIORITY, &vddh_api);
diff --git a/app/drivers/sensor/battery/battery_voltage_divider.c b/app/drivers/sensor/battery/battery_voltage_divider.c
new file mode 100644
index 0000000..8981fb3
--- /dev/null
+++ b/app/drivers/sensor/battery/battery_voltage_divider.c
@@ -0,0 +1,193 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#define DT_DRV_COMPAT zmk_battery_voltage_divider
+
+#include <device.h>
+#include <devicetree.h>
+#include <drivers/gpio.h>
+#include <drivers/adc.h>
+#include <drivers/sensor.h>
+#include <logging/log.h>
+
+#include "battery_common.h"
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+struct io_channel_config {
+ const char *label;
+ uint8_t channel;
+};
+
+struct gpio_channel_config {
+ const char *label;
+ uint8_t pin;
+ uint8_t flags;
+};
+
+struct bvd_config {
+ struct io_channel_config io_channel;
+ struct gpio_channel_config power_gpios;
+ uint32_t output_ohm;
+ uint32_t full_ohm;
+};
+
+struct bvd_data {
+ const struct device *adc;
+ const struct device *gpio;
+ struct adc_channel_cfg acc;
+ struct adc_sequence as;
+ struct battery_value value;
+};
+
+static int bvd_sample_fetch(const struct device *dev, enum sensor_channel chan) {
+ struct bvd_data *drv_data = dev->data;
+ const struct bvd_config *drv_cfg = dev->config;
+ struct adc_sequence *as = &drv_data->as;
+
+ // Make sure selected channel is supported
+ if (chan != SENSOR_CHAN_GAUGE_VOLTAGE && chan != SENSOR_CHAN_GAUGE_STATE_OF_CHARGE &&
+ chan != SENSOR_CHAN_ALL) {
+ LOG_DBG("Selected channel is not supported: %d.", chan);
+ return -ENOTSUP;
+ }
+
+ int rc = 0;
+
+ // Enable power GPIO if present
+ if (drv_data->gpio) {
+ rc = gpio_pin_set(drv_data->gpio, drv_cfg->power_gpios.pin, 1);
+
+ if (rc != 0) {
+ LOG_DBG("Failed to enable ADC power GPIO: %d", rc);
+ return rc;
+ }
+
+ // wait for any capacitance to charge up
+ k_sleep(K_MSEC(10));
+ }
+
+ // Read ADC
+ rc = adc_read(drv_data->adc, as);
+ as->calibrate = false;
+
+ if (rc == 0) {
+ int32_t val = drv_data->value.adc_raw;
+
+ adc_raw_to_millivolts(adc_ref_internal(drv_data->adc), drv_data->acc.gain, as->resolution,
+ &val);
+
+ uint16_t millivolts = val * (uint64_t)drv_cfg->full_ohm / drv_cfg->output_ohm;
+ LOG_DBG("ADC raw %d ~ %d mV => %d mV", drv_data->value.adc_raw, val, millivolts);
+ uint8_t percent = lithium_ion_mv_to_pct(millivolts);
+ LOG_DBG("Percent: %d", percent);
+
+ drv_data->value.millivolts = millivolts;
+ drv_data->value.state_of_charge = percent;
+ } else {
+ LOG_DBG("Failed to read ADC: %d", rc);
+ }
+
+ // Disable power GPIO if present
+ if (drv_data->gpio) {
+ int rc2 = gpio_pin_set(drv_data->gpio, drv_cfg->power_gpios.pin, 0);
+
+ if (rc2 != 0) {
+ LOG_DBG("Failed to disable ADC power GPIO: %d", rc2);
+ return rc2;
+ }
+ }
+
+ return rc;
+}
+
+static int bvd_channel_get(const struct device *dev, enum sensor_channel chan,
+ struct sensor_value *val) {
+ struct bvd_data *drv_data = dev->data;
+ return battery_channel_get(&drv_data->value, chan, val);
+}
+
+static const struct sensor_driver_api bvd_api = {
+ .sample_fetch = bvd_sample_fetch,
+ .channel_get = bvd_channel_get,
+};
+
+static int bvd_init(const struct device *dev) {
+ struct bvd_data *drv_data = dev->data;
+ const struct bvd_config *drv_cfg = dev->config;
+
+ drv_data->adc = device_get_binding(drv_cfg->io_channel.label);
+
+ if (drv_data->adc == NULL) {
+ LOG_ERR("ADC %s failed to retrieve", drv_cfg->io_channel.label);
+ return -ENODEV;
+ }
+
+ int rc = 0;
+
+ if (drv_cfg->power_gpios.label) {
+ drv_data->gpio = device_get_binding(drv_cfg->power_gpios.label);
+ if (drv_data->gpio == NULL) {
+ LOG_ERR("Failed to get GPIO %s", drv_cfg->power_gpios.label);
+ return -ENODEV;
+ }
+ rc = gpio_pin_configure(drv_data->gpio, drv_cfg->power_gpios.pin,
+ GPIO_OUTPUT_INACTIVE | drv_cfg->power_gpios.flags);
+ if (rc != 0) {
+ LOG_ERR("Failed to control feed %s.%u: %d", drv_cfg->power_gpios.label,
+ drv_cfg->power_gpios.pin, rc);
+ return rc;
+ }
+ }
+
+ drv_data->as = (struct adc_sequence){
+ .channels = BIT(0),
+ .buffer = &drv_data->value.adc_raw,
+ .buffer_size = sizeof(drv_data->value.adc_raw),
+ .oversampling = 4,
+ .calibrate = true,
+ };
+
+#ifdef CONFIG_ADC_NRFX_SAADC
+ drv_data->acc = (struct adc_channel_cfg){
+ .gain = ADC_GAIN_1_5,
+ .reference = ADC_REF_INTERNAL,
+ .acquisition_time = ADC_ACQ_TIME(ADC_ACQ_TIME_MICROSECONDS, 40),
+ .input_positive = SAADC_CH_PSELP_PSELP_AnalogInput0 + drv_cfg->io_channel.channel,
+ };
+
+ drv_data->as.resolution = 12;
+#else
+#error Unsupported ADC
+#endif
+
+ rc = adc_channel_setup(drv_data->adc, &drv_data->acc);
+ LOG_DBG("AIN%u setup returned %d", drv_cfg->io_channel.channel, rc);
+
+ return rc;
+}
+
+static struct bvd_data bvd_data;
+static const struct bvd_config bvd_cfg = {
+ .io_channel =
+ {
+ DT_INST_IO_CHANNELS_LABEL(0),
+ DT_INST_IO_CHANNELS_INPUT(0),
+ },
+#if DT_INST_NODE_HAS_PROP(0, power_gpios)
+ .power_gpios =
+ {
+ DT_INST_GPIO_LABEL(0, power_gpios),
+ DT_INST_GPIO_PIN(0, power_gpios),
+ DT_INST_GPIO_FLAGS(0, power_gpios),
+ },
+#endif
+ .output_ohm = DT_INST_PROP(0, output_ohms),
+ .full_ohm = DT_INST_PROP(0, full_ohms),
+};
+
+DEVICE_DT_INST_DEFINE(0, &bvd_init, device_pm_control_nop, &bvd_data, &bvd_cfg, POST_KERNEL,
+ CONFIG_SENSOR_INIT_PRIORITY, &bvd_api);
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-01 12:26:16 +0000