examples/ads7046: Add new example for ADS7046 ADC

Add a new example that shows how to read a sample from
an ADS7046 ADC sensor registered on the SPI bus.

Signed-off-by: Niccolò Maggioni <nicco.maggioni+nuttx@gmail.com>
This commit is contained in:
Niccolò Maggioni 2025-08-19 17:30:50 +02:00 committed by Xiang Xiao
parent 14a39ee7ce
commit dfd1eb0672
5 changed files with 222 additions and 0 deletions

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# ##############################################################################
# apps/examples/ads7046/CMakeLists.txt
#
# SPDX-License-Identifier: Apache-2.0
#
# Licensed to the Apache Software Foundation (ASF) under one or more contributor
# license agreements. See the NOTICE file distributed with this work for
# additional information regarding copyright ownership. The ASF licenses this
# file to you under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.
#
# ##############################################################################
if(CONFIG_EXAMPLES_ADS7046)
nuttx_add_application(
NAME
${CONFIG_EXAMPLES_ADS7046_PROGNAME}
PRIORITY
${CONFIG_EXAMPLES_ADS7046_PRIORITY}
STACKSIZE
${CONFIG_EXAMPLES_ADS7046_STACKSIZE}
MODULE
${CONFIG_EXAMPLES_ADS7046}
SRCS
ads7046_main.c)
endif()

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examples/ads7046/Kconfig Normal file
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#
# For a description of the syntax of this configuration file,
# see the file kconfig-language.txt in the NuttX tools repository.
#
config EXAMPLES_ADS7046
tristate "ADS7046 ADC example"
default n
depends on ADC_ADS7046
---help---
Enable the ADS7046 example
if EXAMPLES_ADS7046
config EXAMPLES_ADS7046_PROGNAME
string "Program name"
default "ads7046"
---help---
This is the name of the program that will be used when the NSH ELF
program is installed.
config EXAMPLES_ADS7046_PRIORITY
int "ADS7046 task priority"
default 100
config EXAMPLES_ADS7046_STACKSIZE
int "ADS7046 stack size"
default DEFAULT_TASK_STACKSIZE
config EXAMPLES_ADS7046_DEVPATH
string "ADS7046 device path"
default "/dev/adc0"
---help---
The default path to the ADS7046 ADC device
endif

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############################################################################
# apps/examples/ads7046/Make.defs
#
# SPDX-License-Identifier: Apache-2.0
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership. The
# ASF licenses this file to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance with the
# License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#
############################################################################
ifneq ($(CONFIG_EXAMPLES_ADS7046),)
CONFIGURED_APPS += $(APPDIR)/examples/ads7046
endif

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examples/ads7046/Makefile Normal file
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############################################################################
# apps/examples/ads7046/Makefile
#
# SPDX-License-Identifier: Apache-2.0
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership. The
# ASF licenses this file to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance with the
# License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#
############################################################################
include $(APPDIR)/Make.defs
# ADS7046 ADC example built-in application info
PROGNAME = $(CONFIG_EXAMPLES_ADS7046_PROGNAME)
PRIORITY = $(CONFIG_EXAMPLES_ADS7046_PRIORITY)
STACKSIZE = $(CONFIG_EXAMPLES_ADS7046_STACKSIZE)
MODULE = $(CONFIG_EXAMPLES_ADS7046)
# ADS7046 ADC example
MAINSRC = ads7046_main.c
include $(APPDIR)/Application.mk

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/****************************************************************************
* apps/examples/ads7046/ads7046_main.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <nuttx/analog/ioctl.h>
#include <nuttx/analog/ads7046.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* As per the datasheet, the ADS7046 returns the following readings:
* INPUT VOLTAGE (AINP - AINM) DESCRIPTION HEX
* -------------------------------------- ------------------------ ---
* <= 1 LSB Negative full-scale code 000
* 1 LSB to 2 LSB - 001
* V_REF / 2 to V_REF / 2 + 1 LSB Mid code 7FF
* V_REF / 2 + 1 LSB to V_REF / 2 + 2 LSB - 800
* >= V_REF - 1 LSB Positive full-scale code FFF
*/
#define SAMPLE_TO_PCT(sample) (((sample) * 100) / 0xfff)
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: ads7046_main
****************************************************************************/
int main(const int argc, FAR char *argv[])
{
UNUSED(argc);
UNUSED(argv);
int ret;
int fd;
uint16_t sample;
fd = open(CONFIG_EXAMPLES_ADS7046_DEVPATH, O_RDONLY);
if (fd < 0)
{
printf("Failed to open %s: %s (%d)\n", CONFIG_EXAMPLES_ADS7046_DEVPATH,
strerror(errno), errno);
return EXIT_FAILURE;
}
ret = ioctl(fd, ANIOC_ADS7046_READ, &sample);
if (ret != OK)
{
perror("Could not ioctl fd");
close(fd);
return EXIT_FAILURE;
}
printf("ADS7046: hex=%x, dec=%"PRIu16", adc_percentage=%u%%\n",
sample, sample, SAMPLE_TO_PCT(sample));
close(fd);
return EXIT_SUCCESS;
}