adc_example: Add an example about how to use the adc.
This example takes periodic samples using a thread and calculate the rms value and the mean value of the samples taken. https://jira.digi.com/browse/DEL-4889 Signed-off-by: Francisco Gil <francisco.gilmartinez@digi.com>
This commit is contained in:
Francisco Gil
parent
4e013d621a
commit
68f3f0f815
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#
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# Copyright 2017, Digi International Inc.
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#
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# Permission to use, copy, modify, and/or distribute this software for any
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# purpose with or without fee is hereby granted, provided that the above
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# copyright notice and this permission notice appear in all copies.
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#
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# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
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# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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# AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
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# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
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# OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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# PERFORMANCE OF THIS SOFTWARE.
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#
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BINARY := apix-adc-example
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CFLAGS += -Wall -O2
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CFLAGS += $(shell pkg-config --cflags libdigiapix)
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LDLIBS += $(shell pkg-config --libs libdigiapix)
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$(BINARY): main.o
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$(CC) $(LDFLAGS) $^ $(LDLIBS) -o $@ -lm
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.PHONY: install
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install: $(BINARY)
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install -d $(DESTDIR)/usr/bin
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install -m 0755 $^ $(DESTDIR)/usr/bin/
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.PHONY: all
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all: $(BINARY)
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.PHONY: clean
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clean:
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-rm -f *.o $(BINARY)
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Digi APIX ADC Sample Application
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===================================
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Sample application to access and manage ADC channels using the Digi APIX library.
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The application enables one ADC channel on the board. After that, the application
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takes periodic samples and calculates the rms and mean value of the samples batch.
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The ADC lines used in the sample are mapped as follows in the Digi Boards:
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- **CCIMX6 SBC**: PMIC_ADCIN1 (GPIO Connector Pin 1).
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- **CCIMX6UL SBC Express**: ADC1_IN4 (Expansion Connector Pin 7).
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- **CCIMX6UL SBC Pro**: ADC1_IN2 (GPIO Connector Pin 13).
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The following device tree modifications are required for the sample to work:
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- **CCIMX6 SBC**: _No device tree modifications are required._
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- **CCIMX6UL SBC Express**:
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```
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&adc1 {
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pinctrl-names = "default";
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pinctrl-0 = <&pinctrl_adc1>;
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adc-ch-list = <4>;
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status = "okay";
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};
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&iomuxc {
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imx6ul-ccimx6ul {
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pinctrl_adc1: adc1grp {
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fsl,pins = <
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MX6UL_PAD_GPIO1_IO04__GPIO1_IO04 0xb0
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>;
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};
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};
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};
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```
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- **CCIMX6UL SBC Pro**:
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```
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&adc1 {
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pinctrl-names = "default";
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pinctrl-0 = <&pinctrl_adc1>;
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adc-ch-list = <2>;
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status = "okay";
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};
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&iomuxc {
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imx6ul-ccimx6ul {
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pinctrl_adc1: adc1grp {
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fsl,pins = <
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MX6UL_PAD_GPIO1_IO02__GPIO1_IO02 0xb0
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>;
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};
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};
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};
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```
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Running the application
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-----------------------
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Once the binary is in the target, launch the application:
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```
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#> apix-adc-example [adc_chip adc_channel interval number_of_samples]
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```
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Where:
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- 'adc_chip' the ADC chip number.
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- 'adc_channel' the ADC channel number.
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- 'interval' is the time interval between samples.
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- 'number_of_samples' is the number of samples to take.
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Compiling the application
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-------------------------
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This demo can be compiled using a Digi Embedded Yocto based toolchain. Make
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sure to source the corresponding toolchain of the platform you are using, e.g:
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```
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$> . <DEY-toolchain-path>/environment-setup-cortexa7hf-vfp-neon-dey-linux-gnueabi
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$> make
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```
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More information about [Digi Embedded Yocto](https://github.com/digi-embedded/meta-digi).
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License
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-------
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Copyright 2017, Digi International Inc.
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Permission to use, copy, modify, and/or distribute this software for any purpose
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with or without fee is hereby granted, provided that the above copyright notice
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and this permission notice appear in all copies.
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THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
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REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
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FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
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INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
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OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
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TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
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THIS SOFTWARE.
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@ -0,0 +1,229 @@
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/*
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* Copyright 2017, Digi International Inc.
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
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* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
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* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
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* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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* PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <errno.h>
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#include <libgen.h>
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#include <limits.h>
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#include <math.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include "libdigiapix/adc.h"
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#define ARG_ADC_CHIP 0
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#define ARG_ADC_CHANNEL 1
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static adc_t *adc;
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struct adc_sampling_cb_data {
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adc_t *adc;
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int total_value;
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int total_value_rms;
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int number_of_samples;
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};
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/*
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* usage_and_exit() - Show usage information and exit with 'exitval' return
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* value
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*
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* @name: Application name.
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* @exitval: The exit code.
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*/
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static void usage_and_exit(char *name, int exitval)
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{
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fprintf(stdout,
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"Example application using libdigiapix ADC support\n"
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"\n"
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"Usage: %s <adc_chip> <adc_channel> <interval> <number_of_samples> \n\n"
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"<adc_chip> ADC chip number\n"
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"<adc_channel> ADC channel number\n"
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"<interval> Time interval for sampling\n"
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"<number_of_samples> Number of samples to get\n"
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"\n\n"
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"\n", name);
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exit(exitval);
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}
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/*
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* cleanup() - Frees all the allocated memory before exiting
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*/
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static void cleanup(void)
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{
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/* Free adc */
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ldx_adc_stop_sampling(adc);
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ldx_adc_free(adc);
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}
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/*
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* sigaction_handler() - Handler to execute after receiving a signal
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*
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* @signum: Received signal.
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*/
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static void sigaction_handler(int signum)
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{
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/* 'atexit' executes the cleanup function */
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exit(EXIT_FAILURE);
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}
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/*
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* register_signals() - Registers program signals
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*/
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static void register_signals(void)
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{
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struct sigaction action;
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action.sa_handler = sigaction_handler;
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action.sa_flags = 0;
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sigemptyset(&action.sa_mask);
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sigaction(SIGHUP, &action, NULL);
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sigaction(SIGINT, &action, NULL);
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sigaction(SIGTERM, &action, NULL);
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}
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/*
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* parse_argument() - Parses the given string argument and returns the
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* corresponding integer value
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*
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* @argv: Argument to parse in string format.
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* @arg_type: Type of the argument to parse.
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*
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* Return: The parsed integer argument, -1 on error.
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*/
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static int parse_argument(char *argv, int arg_type)
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{
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char *endptr;
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long value;
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errno = 0;
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value = strtol(argv, &endptr, 10);
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if ((errno == ERANGE && (value == LONG_MAX || value == LONG_MIN))
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|| (errno != 0 && value == 0))
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return -1;
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if (endptr == argv) {
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switch (arg_type) {
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case ARG_ADC_CHIP:
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return ldx_adc_get_chip(endptr);
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case ARG_ADC_CHANNEL:
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return ldx_adc_get_channel(endptr);
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default:
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return -1;
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}
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}
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return value;
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}
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/*
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* adc_sampling_cb() - ADC callback for sampling
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*
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* @arg: ADC sampling data (struct adc_sampling_cb_data).
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* @sample: The ADC read sample.
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*/
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static int adc_sampling_cb(int sample, void *arg)
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{
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struct adc_sampling_cb_data *data = arg;
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float sample_mv = 0;
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data->total_value += sample;
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data->total_value_rms += powf(sample, 2);
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data->number_of_samples--;
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sample_mv = ldx_adc_convert_sample_to_mv(data->adc, sample);
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printf("ADC sample acquired: %d (raw) - %2.f (mV)\n", sample, sample_mv);
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return EXIT_SUCCESS;
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}
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int main(int argc, char *argv[])
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{
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unsigned int channel, chip, interval;
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int number_of_samples;
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char *name = basename(argv[0]);
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struct adc_sampling_cb_data cb_data;
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/* Check input parameters */
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if (argc != 5) {
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usage_and_exit(name, EXIT_FAILURE);
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return EXIT_FAILURE;
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}
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/* Parse command line arguments */
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chip = parse_argument(argv[1], ARG_ADC_CHIP);
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channel = parse_argument(argv[2], ARG_ADC_CHANNEL);
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interval = atoi(argv[3]);
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number_of_samples = atoi(argv[4]);
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if (chip < 0) {
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printf("Invalid chip number\n");
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return EXIT_FAILURE;
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}
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if (channel < 0) {
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printf("Invalid channel number\n");
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return EXIT_FAILURE;
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}
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if (interval <= 0) {
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printf("Time interval must be greater than 0\n");
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return EXIT_FAILURE;
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}
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if (number_of_samples <= 0) {
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printf("Number of samples must be greater than 0\n");
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return EXIT_FAILURE;
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}
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cb_data.number_of_samples = number_of_samples;
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cb_data.total_value = 0;
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cb_data.total_value_rms = 0;
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/* Register signals and exit cleanup function */
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atexit(cleanup);
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register_signals();
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adc = ldx_adc_request(chip,channel);
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if (!adc) {
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printf("Failed to initialize ADC\n");
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return EXIT_FAILURE;
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}
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cb_data.adc = adc;
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if (ldx_adc_start_sampling(adc, &adc_sampling_cb, interval, &cb_data)) {
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printf("Failed to initialize the sampling data\n");
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return EXIT_FAILURE;
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}
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while (cb_data.number_of_samples > 0) {
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printf("Waiting for samples, %d samples remaining\n",
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cb_data.number_of_samples);
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sleep(1);
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}
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printf("The mean value of the samples is: %d mV\n",
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cb_data.total_value/number_of_samples);
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printf("The RMS value of the samples is: %.2f mV\n",
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sqrt(cb_data.total_value_rms/number_of_samples));
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return EXIT_SUCCESS;
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}
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@ -14,7 +14,7 @@
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# PERFORMANCE OF THIS SOFTWARE.
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#
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SUBDIRS := apix-gpio-example apix-i2c-example apix-pwm-example apix-spi-example
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SUBDIRS := apix-gpio-example apix-i2c-example apix-pwm-example apix-spi-example apix-adc-example
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all: $(SUBDIRS)
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@ -64,4 +64,18 @@ the number of address bytes.
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<platform>ccimx6ulsbc</platform>
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</platforms>
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</sample>
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<sample id="apix-adc-sample">
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<name>Digi APIX ADC Sample</name>
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<description>
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Sample application to access and manage ADC channels using the Digi APIX library.
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The application enables one ADC channel on the board. After that, the application takes periodic samples and calculates the rms and mean value of the samples batch.
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</description>
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<path>apix-adc-example</path>
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<platforms>
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<platform>ccimx6sbc</platform>
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<platform>ccimx6qpsbc</platform>
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<platform>ccimx6ulstarter</platform>
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<platform>ccimx6ulsbc</platform>
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</platforms>
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</sample>
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</samples>
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