sensors: add ads7953 adc

* sensors: add ads7953 adc

* Update src/drivers/adc/ads7953/ADS7953.h

Co-authored-by: Jacob Dahl <37091262+dakejahl@users.noreply.github.com>

* Implemented changes suggested by review

* Implemented suggested changes

* removed unused variables and moved scope of ch_id

* Activated distance sensor again

* Update msg/AdcReport.msg

Co-authored-by: Hamish Willee <hamishwillee@gmail.com>

* Update ADC report message field comments

* Update ADC msg - fix layout

* update comments

* changed group to Sensors in module.yaml

* created new module subcategory "adc"

* reverted group change in module.yaml

* added module descrption to modules_driver.md

* removed module description in modules_driver.md (autogenerated)

* removed unused variable, changed board_adc publication method to "multi"

* added static assert

---------

Co-authored-by: Jacob Dahl <37091262+dakejahl@users.noreply.github.com>
Co-authored-by: Hamish Willee <hamishwillee@gmail.com>

ROMFS/px4fmu_common/init.d/rc.sensors

@@ -219,6 +219,12 @@ then
 	pcf8583 start -X -a 0x51
 fi
 
+# ADC sensor ADS7953 external SPI
+if param compare -s ADC_ADS7953_EN 1
+then
+	ads7953 start -S
+fi
+
 # probe for optional external I2C devices
 if param compare SENS_EXT_I2C_PRB 1
 then

Tools/px4moduledoc/srcparser.py

@@ -15,7 +15,7 @@ class ModuleDocumentation(object):
     # TOC in https://github.com/PX4/PX4-Autopilot/blob/main/docs/en/SUMMARY.md
     valid_categories = ['driver', 'estimator', 'controller', 'system',
                         'communication', 'command', 'template', 'simulation', 'autotune']
-    valid_subcategories = ['', 'camera', 'distance_sensor', 'imu', 'ins', 'airspeed_sensor',
+    valid_subcategories = ['', 'adc', 'camera', 'distance_sensor', 'imu', 'ins', 'airspeed_sensor',
                            'magnetometer', 'baro', 'optical_flow', 'radio_control','rpm_sensor', 'transponder']
 
     max_line_length = 80 # wrap lines that are longer than this

msg/AdcReport.msg

@@ -1,6 +1,10 @@
-uint64 timestamp		# time since system start (microseconds)
-uint32 device_id		# unique device ID for the sensor that does not change between power cycles
-int16[12] channel_id		# ADC channel IDs, negative for non-existent, TODO: should be kept same as array index
-int32[12] raw_data		# ADC channel raw value, accept negative value, valid if channel ID is positive
-uint32 resolution		# ADC channel resolution
-float32 v_ref			# ADC channel voltage reference, use to calculate LSB voltage(lsb=scale/resolution)
+# ADC raw data.
+#
+# Communicates raw data from an analog-to-digital converter (ADC) to other modules, such as battery status.
+
+uint64 timestamp      # [us] Time since system start
+uint32 device_id      # [-] unique device ID for the sensor that does not change between power cycles
+int16[16] channel_id  # [-] ADC channel IDs, negative for non-existent, TODO: should be kept same as array index
+int32[16] raw_data    # [-] ADC channel raw value, accept negative value, valid if channel ID is positive
+uint32 resolution     # [-] ADC channel resolution
+float32 v_ref         # [V] ADC channel voltage reference, use to calculate LSB voltage(lsb=scale/resolution)

src/drivers/adc/ads7953/ADS7953.cpp

@@ -0,0 +1,122 @@
+
+#include "ADS7953.h"
+#include <px4_platform_common/getopt.h>
+#include <px4_platform_common/module.h>
+#include <drivers/drv_adc.h>
+#include <parameters/param.h>
+
+ADS7953::ADS7953(const I2CSPIDriverConfig &config) :
+	SPI(config),
+	I2CSPIDriver(config),
+	ModuleParams(nullptr)
+{
+	static_assert(arraySize(adc_report_s::channel_id) >= NUM_CHANNELS, "ADS7953 reports 16 channels");
+}
+
+int ADS7953::init()
+{
+	int ret = SPI::init();
+
+	if (ret != PX4_OK) {
+		PX4_DEBUG("SPI::init failed (%i)", ret);
+		return ret;
+	}
+
+	_adc_report.device_id = this->get_device_id();
+	_adc_report.v_ref = _adc_ads7953_refv.get();
+	_adc_report.resolution = 4096;
+
+	for (unsigned i = 0; i < PX4_MAX_ADC_CHANNELS; ++i) {
+		_adc_report.channel_id[i] = -1;
+	}
+
+	ScheduleOnInterval(10_ms);
+	return PX4_OK;
+}
+
+int ADS7953::probe()
+{
+	// The ADS7953 has no ID register which we can check, so we verify the device via the returned channel ID.
+	// We set the mode to "manual mode" and the channel to measure to 1.
+	// If the returned channel ID on the third message is 1, we assume the ADS7953 is connected.
+	uint8_t recv_data[2];
+
+	int ret = rw_msg(&recv_data[0], 1, true);
+
+	if (ret != PX4_OK) {
+		PX4_DEBUG("ADS7953 probing failed (%i)", ret);
+		return ret;
+	}
+
+	ret |= rw_msg(&recv_data[0], 0, false);
+	ret |= rw_msg(&recv_data[0], 0, true);
+
+	if (ret != PX4_OK || (recv_data[0] >> 4) != 1U) {
+		PX4_DEBUG("ADS7953 probing failed (%i)", ret);
+		return PX4_ERROR;
+	}
+
+	PX4_INFO("ADS7953 was found");
+	return PX4_OK;
+}
+
+int ADS7953::rw_msg(uint8_t *recv_data, uint8_t ch, bool change_channel)
+{
+	uint8_t send_data[2];
+
+	if (change_channel) {
+		send_data[0] = 0x10 | (ch >> 1);
+		send_data[1] = 0x00 | (ch << 7);
+
+	} else {
+		send_data[0] = 0x00;
+		send_data[1] = 0x00;
+	}
+
+	return transfer(&send_data[0], &recv_data[0], 2);
+}
+
+int ADS7953::get_measurements()
+{
+	uint8_t recv_data[2];
+	int count = 0;
+	uint16_t mask = 0x00;
+	uint8_t idx = 0;
+
+	while (count < NUM_CHANNELS) {
+		if (rw_msg(&recv_data[0], idx, true) == PX4_OK) {
+			uint8_t ch_id = (recv_data[0] >> 4);
+
+			//check if we already have a measurement for the returned channel
+			if (!(mask & (1U << ch_id))) {
+				mask |= (1U << ch_id);
+				count++;
+				_adc_report.channel_id[ch_id] = ch_id;
+				_adc_report.raw_data[ch_id] = ((((uint16_t) recv_data[0]) & 0x0F) << 8) | recv_data[1];
+			}
+		}
+
+		// Find index to measure next
+		for (int i = 1; i <= NUM_CHANNELS; i++) {
+			uint8_t candidate_id = (idx + i) % NUM_CHANNELS;
+
+			if (!(mask & (1U << candidate_id))) {
+				idx = candidate_id;
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+
+void ADS7953::RunImpl()
+{
+	get_measurements();
+	_adc_report.timestamp = hrt_absolute_time();
+	_adc_report_pub.publish(_adc_report);
+
+	for (unsigned i = 0; i < PX4_MAX_ADC_CHANNELS; ++i) {
+		_adc_report.channel_id[i] = -1;
+	}
+}

src/drivers/adc/ads7953/ADS7953.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <drivers/device/spi.h>
+#include <drivers/drv_hrt.h>
+#include <px4_platform_common/i2c_spi_buses.h>
+#include <lib/drivers/device/spi.h>
+#include <lib/parameters/param.h>
+#include <uORB/topics/adc_report.h>
+#include <uORB/PublicationMulti.hpp>
+#include <lib/mixer_module/mixer_module.hpp>
+#include <px4_platform_common/module_params.h>
+#include <uORB/topics/parameter_update.h>
+#include <uORB/Subscription.hpp>
+
+using namespace time_literals;
+
+
+class ADS7953 : public device::SPI, public I2CSPIDriver<ADS7953>, public ModuleParams
+{
+public:
+	ADS7953(const I2CSPIDriverConfig &config);
+	virtual ~ADS7953() = default;
+	static void print_usage();
+
+	int init() override;
+	void RunImpl();
+	int probe() override;
+
+
+private:
+	static constexpr int NUM_CHANNELS = 16;
+	uORB::PublicationMulti<adc_report_s> _adc_report_pub{ORB_ID(adc_report)};
+
+	static const hrt_abstime SAMPLE_INTERVAL{50_ms};
+
+	DEFINE_PARAMETERS(
+		(ParamFloat<px4::params::ADC_ADS7953_REFV>) _adc_ads7953_refv
+	)
+	adc_report_s _adc_report{};
+
+	int get_measurements();
+	int rw_msg(uint8_t *recv_data, uint8_t ch, bool change_channel);
+};

src/drivers/adc/ads7953/CMakeLists.txt

@@ -0,0 +1,46 @@
+############################################################################
+#
+#   Copyright (c) 2025 PX4 Development Team. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name PX4 nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+px4_add_module(
+	MODULE drivers__adc__ads7953
+	MAIN ads7953
+	COMPILE_FLAGS
+	SRCS
+		ADS7953.cpp
+		ADS7953.h
+		ads7953_main.cpp
+	MODULE_CONFIG
+		module.yaml
+	DEPENDS
+		px4_work_queue
+	)

src/drivers/adc/ads7953/Kconfig

@@ -0,0 +1,5 @@
+menuconfig DRIVERS_ADC_ADS7953
+	bool "ADS7953 driver"
+	default n
+	---help---
+		Enable support for ADS7953

src/drivers/adc/ads7953/ads7953_main.cpp

@@ -0,0 +1,77 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2025 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#include <px4_platform_common/getopt.h>
+#include <px4_platform_common/module.h>
+#include "ADS7953.h"
+
+void ADS7953::print_usage()
+{
+	PRINT_MODULE_USAGE_NAME("ads7953", "driver");
+	PRINT_MODULE_USAGE_SUBCATEGORY("adc");
+	PRINT_MODULE_USAGE_COMMAND("start");
+	PRINT_MODULE_USAGE_PARAMS_I2C_SPI_DRIVER(false, true);
+	PRINT_MODULE_USAGE_DEFAULT_COMMANDS();
+}
+
+extern "C" int ads7953_main(int argc, char *argv[])
+{
+	using ThisDriver = ADS7953;
+	BusCLIArguments cli{false, true};
+	cli.spi_mode = SPIDEV_MODE0;
+	cli.default_spi_frequency = 10 * 1000 * 1000;
+	const char *name = MODULE_NAME;
+	const char *verb = cli.parseDefaultArguments(argc, argv);
+
+	if (!verb) {
+		ThisDriver::print_usage();
+		return -1;
+	}
+
+	BusInstanceIterator iterator(name, cli, DRV_ADC_DEVTYPE_ADS7953);
+
+	if (!strcmp(verb, "start")) {
+		return ThisDriver::module_start(cli, iterator);
+	}
+
+	if (!strcmp(verb, "stop")) {
+		return ThisDriver::module_stop(iterator);
+	}
+
+	if (!strcmp(verb, "status")) {
+		return ThisDriver::module_status(iterator);
+	}
+
+	ThisDriver::print_usage();
+	return -1;
+}

src/drivers/adc/ads7953/module.yaml

@@ -0,0 +1,29 @@
+__max_num_config_instances: &max_num_config_instances 1
+
+module_name: ADS7953
+
+parameters:
+  - group: ADC
+    definitions:
+      ADC_ADS7953_EN:
+        description:
+            short: Enable ADS7953
+            long: |
+                Enable the driver for the ADS7953 board
+        type: boolean
+        reboot_required: true
+        default: 0
+
+      ADC_ADS7953_REFV:
+        description:
+            short: Applied reference Voltage.
+            long: |
+                The voltage applied to the ADS7953 board as reference
+        type: float
+        unit: V
+        min: 2.0
+        max: 3.0
+        decimal: 2
+        increment: 0.01
+        reboot_required: true
+        default: 2.5

src/drivers/adc/board_adc/ADC.hpp

@@ -50,6 +50,7 @@
 #include <px4_platform_common/px4_config.h>
 #include <px4_platform_common/px4_work_queue/ScheduledWorkItem.hpp>
 #include <uORB/Publication.hpp>
+#include <uORB/PublicationMulti.hpp>
 #include <uORB/topics/adc_report.h>
 #include <uORB/topics/system_power.h>
 
@@ -110,7 +111,7 @@ private:
 	const uint32_t			_base_address;
 	px4_adc_msg_t			*_samples{nullptr};	/**< sample buffer */
 
-	uORB::Publication<adc_report_s>		_to_adc_report{ORB_ID(adc_report)};
+	uORB::PublicationMulti<adc_report_s>	_to_adc_report{ORB_ID(adc_report)};
 	uORB::Publication<system_power_s>	_to_system_power{ORB_ID(system_power)};
 
 #ifdef BOARD_GPIO_VDD_5V_COMP_VALID

src/drivers/drv_sensor.h

@@ -260,6 +260,8 @@
 
 #define DRV_INS_DEVTYPE_SBG		0xEC
 
+#define DRV_ADC_DEVTYPE_ADS7953 0xED
+
 #define DRV_DEVTYPE_UNUSED		0xff
 
 #endif /* _DRV_SENSOR_H */