diff --git a/app/boards/arm/bluemicro840/Kconfig.defconfig b/app/boards/arm/bluemicro840/Kconfig.defconfig index 566b5a42..2b55e17c 100644 --- a/app/boards/arm/bluemicro840/Kconfig.defconfig +++ b/app/boards/arm/bluemicro840/Kconfig.defconfig @@ -27,4 +27,7 @@ config ZMK_BLE config ZMK_USB default y +config ZMK_BATTERY_VOLTAGE_DIVIDER + default y + endif # BOARD_BLUEMICRO840_V1 diff --git a/app/boards/arm/bluemicro840/bluemicro840_v1.dts b/app/boards/arm/bluemicro840/bluemicro840_v1.dts index c693662a..32aa2e6f 100644 --- a/app/boards/arm/bluemicro840/bluemicro840_v1.dts +++ b/app/boards/arm/bluemicro840/bluemicro840_v1.dts @@ -29,6 +29,18 @@ }; }; + vbatt { + compatible = "zmk,battery-voltage-divider"; + label = "VOLTAGE_DIVIDER"; + io-channels = <&adc 7>; + output-ohms = <2000000>; + full-ohms = <(2000000 + 806000)>; + }; + +}; + +&adc { + status = "okay"; }; &gpio0 { diff --git a/app/boards/arm/nice_nano/Kconfig.defconfig b/app/boards/arm/nice_nano/Kconfig.defconfig index 0961ddd1..205050af 100644 --- a/app/boards/arm/nice_nano/Kconfig.defconfig +++ b/app/boards/arm/nice_nano/Kconfig.defconfig @@ -25,4 +25,7 @@ config ZMK_BLE config ZMK_USB default y +config ZMK_BATTERY_VOLTAGE_DIVIDER + default y + endif # BOARD_NICE_NANO diff --git a/app/boards/arm/nice_nano/nice_nano.dts b/app/boards/arm/nice_nano/nice_nano.dts index 0538b1df..18195412 100644 --- a/app/boards/arm/nice_nano/nice_nano.dts +++ b/app/boards/arm/nice_nano/nice_nano.dts @@ -34,6 +34,18 @@ label = "EXT_POWER"; control-gpios = <&gpio0 13 GPIO_ACTIVE_LOW>; }; + + vbatt { + compatible = "zmk,battery-voltage-divider"; + label = "VOLTAGE_DIVIDER"; + io-channels = <&adc 2>; + output-ohms = <2000000>; + full-ohms = <(2000000 + 806000)>; + }; +}; + +&adc { + status = "okay"; }; &gpiote { diff --git a/app/boards/arm/nrfmicro/Kconfig.defconfig b/app/boards/arm/nrfmicro/Kconfig.defconfig index 7957b4a5..a3c02c22 100644 --- a/app/boards/arm/nrfmicro/Kconfig.defconfig +++ b/app/boards/arm/nrfmicro/Kconfig.defconfig @@ -35,6 +35,9 @@ if BOARD_NRFMICRO_13 config BOARD_NRFMICRO_CHARGER default y +config ZMK_BATTERY_VOLTAGE_DIVIDER + default y + endif # BOARD_NRFMICRO_13 endif # BOARD_NRFMICRO_11 || BOARD_NRFMICRO_11_FLIPPED || BOARD_NRFMICRO_13 diff --git a/app/boards/arm/nrfmicro/nrfmicro_13.dts b/app/boards/arm/nrfmicro/nrfmicro_13.dts index ef439462..5ae11ba0 100644 --- a/app/boards/arm/nrfmicro/nrfmicro_13.dts +++ b/app/boards/arm/nrfmicro/nrfmicro_13.dts @@ -31,6 +31,18 @@ label = "EXT_POWER"; control-gpios = <&gpio1 9 GPIO_ACTIVE_LOW>; }; + + vbatt { + compatible = "zmk,battery-voltage-divider"; + label = "VOLTAGE_DIVIDER"; + io-channels = <&adc 2>; + output-ohms = <2000000>; + full-ohms = <(2000000 + 820000)>; + }; +}; + +&adc { + status = "okay"; }; &gpio0 { diff --git a/app/drivers/zephyr/CMakeLists.txt b/app/drivers/zephyr/CMakeLists.txt index 8778ded3..fc43fb8c 100644 --- a/app/drivers/zephyr/CMakeLists.txt +++ b/app/drivers/zephyr/CMakeLists.txt @@ -9,4 +9,5 @@ if(CONFIG_ZMK_KSCAN_GPIO_DRIVER) zephyr_library_sources_ifdef(CONFIG_EC11 ec11.c) zephyr_library_sources_ifdef(CONFIG_EC11_TRIGGER ec11_trigger.c) + zephyr_library_sources_ifdef(CONFIG_ZMK_BATTERY_VOLTAGE_DIVIDER battery_voltage_divider.c) endif() diff --git a/app/drivers/zephyr/Kconfig b/app/drivers/zephyr/Kconfig index 0534cab2..6b177fb1 100644 --- a/app/drivers/zephyr/Kconfig +++ b/app/drivers/zephyr/Kconfig @@ -21,6 +21,12 @@ config ZMK_KSCAN_INIT_PRIORITY help Keyboard scan device driver initialization priority. +config ZMK_BATTERY_VOLTAGE_DIVIDER + bool "ZMK battery voltage divider" + select ADC + help + Enable ZMK battery voltage divider driver for battery monitoring. + menuconfig EC11 bool "EC11 Incremental Encoder Sensor" depends on GPIO diff --git a/app/drivers/zephyr/battery_voltage_divider.c b/app/drivers/zephyr/battery_voltage_divider.c new file mode 100644 index 00000000..37ac024b --- /dev/null +++ b/app/drivers/zephyr/battery_voltage_divider.c @@ -0,0 +1,215 @@ +/* + * Copyright (c) 2020 The ZMK Contributors + * + * SPDX-License-Identifier: MIT + */ + +#define DT_DRV_COMPAT zmk_battery_voltage_divider + +#include +#include +#include +#include +#include + +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 { + struct device *adc; + struct device *gpio; + struct adc_channel_cfg acc; + struct adc_sequence as; + uint16_t adc_raw; + uint16_t voltage; + uint8_t state_of_charge; +}; + +static 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; +} + +static int bvd_sample_fetch(struct device *dev, enum sensor_channel chan) { + struct bvd_data *drv_data = dev->driver_data; + const struct bvd_config *drv_cfg = dev->config_info; + 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) { + 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; + } + } + + // Read ADC + rc = adc_read(drv_data->adc, as); + as->calibrate = false; + + if (rc == 0) { + int32_t val = drv_data->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\n", drv_data->adc_raw, val, millivolts); + uint8_t percent = lithium_ion_mv_to_pct(millivolts); + LOG_DBG("Percent: %d", percent); + + drv_data->voltage = millivolts; + drv_data->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(struct device *dev, enum sensor_channel chan, struct sensor_value *val) { + struct bvd_data *drv_data = dev->driver_data; + + switch (chan) { + case SENSOR_CHAN_GAUGE_VOLTAGE: + val->val1 = drv_data->voltage / 1000; + val->val2 = (drv_data->voltage % 1000) * 1000U; + break; + + case SENSOR_CHAN_GAUGE_STATE_OF_CHARGE: + val->val1 = drv_data->state_of_charge; + val->val2 = 0; + break; + + default: + return -ENOTSUP; + } + + return 0; +} + +static const struct sensor_driver_api bvd_api = { + .sample_fetch = bvd_sample_fetch, + .channel_get = bvd_channel_get, +}; + +static int bvd_init(struct device *dev) { + struct bvd_data *drv_data = dev->driver_data; + const struct bvd_config *drv_cfg = dev->config_info; + + 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->adc_raw, + .buffer_size = sizeof(drv_data->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_PIN(0, power_gpios), + DT_INST_FLAGS(0, power_gpios), + }, +#endif + .output_ohm = DT_INST_PROP(0, output_ohms), + .full_ohm = DT_INST_PROP(0, full_ohms), +}; + +DEVICE_AND_API_INIT(bvd_dev, DT_INST_LABEL(0), &bvd_init, &bvd_data, &bvd_cfg, POST_KERNEL, + CONFIG_SENSOR_INIT_PRIORITY, &bvd_api); diff --git a/app/drivers/zephyr/dts/bindings/zmk,battery-voltage-divider.yaml b/app/drivers/zephyr/dts/bindings/zmk,battery-voltage-divider.yaml new file mode 100644 index 00000000..3f391d78 --- /dev/null +++ b/app/drivers/zephyr/dts/bindings/zmk,battery-voltage-divider.yaml @@ -0,0 +1,14 @@ +# Copyright (c) 2020 The ZMK Contributors +# SPDX-License-Identifier: MIT + +description: Battery SoC monitoring using voltage divider + +compatible: "zmk,battery-voltage-divider" + +include: voltage-divider.yaml + +properties: + label: + required: true + type: string + \ No newline at end of file