patrick/zephyr
1
0
Fork 0
Code Issues Pull requests Actions 8 Packages Projects Releases Wiki Activity

samples: shields: lmp90100_evb: rtd: convert to devicetree configuration

Browse source 
Convert the sample for the lmp90100_evb shield to use devicetree for
configuring the ADC channel.

Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>
This commit is contained in:
Henrik Brix Andersen 2024-01-07 19:36:27 +01:00 committed by Carles Cufí
parent df83fffc7c
commit d856ed73f4
2 changed files with 40 additions and 30 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
samples/shields/lmp90100_evb/rtd/app.overlay
View file

@ -1,9 +1,29 @@
/*
* Copyright (c) 2019 Vestas Wind Systems A/S
* Copyright (c) 2019-2024 Vestas Wind Systems A/S
*
* SPDX-License-Identifier: Apache-2.0
*/
&lmp90100_lmp90100_evb {
rtd-current = <1000>;
/ {
zephyr,user {
io-channels = <&lmp90100_lmp90100_evb 0>;
};
};
&lmp90100_lmp90100_evb {
#address-cells = <1>;
#size-cells = <0>;
rtd-current = <1000>;
channel@0 {
reg = <0>;
zephyr,gain = "ADC_GAIN_1";
zephyr,reference = "ADC_REF_EXTERNAL1";
zephyr,acquisition-time = <ADC_ACQ_TIME(ADC_ACQ_TIME_TICKS, 0)>;
zephyr,resolution = <24>;
zephyr,differential;
zephyr,input-positive = <0>;
zephyr,input-negative = <1>;
};
};

44
samples/shields/lmp90100_evb/rtd/src/main.c
View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2019 Vestas Wind Systems A/S
* Copyright (c) 2019-2024 Vestas Wind Systems A/S
*
* SPDX-License-Identifier: Apache-2.0
*/
@ -17,11 +17,8 @@ LOG_MODULE_REGISTER(main);
/* Nominal RTD (PT100) resistance in ohms */
#define RTD_NOMINAL_RESISTANCE 100
/* ADC resolution in bits */
#define ADC_RESOLUTION 24U
/* ADC maximum value (taking sign bit into consideration) */
#define ADC_MAX BIT_MASK(ADC_RESOLUTION - 1)
#define ADC_MAX(resolution) BIT_MASK(resolution - 1)
/* Bottom resistor value in ohms */
#define BOTTOM_RESISTANCE 2000
@ -42,46 +39,39 @@ static double rtd_temperature(int nom, double resistance)
int main(void)
{
const struct device *const lmp90100 = DEVICE_DT_GET_ONE(ti_lmp90100);
const struct adc_dt_spec ch_cfg = ADC_DT_SPEC_GET(DT_PATH(zephyr_user));
double adc_max = ADC_MAX(ch_cfg.resolution);
double resistance;
int32_t buffer;
int err;
const struct adc_channel_cfg ch_cfg = {
.channel_id = 0,
.differential = 1,
.input_positive = 0,
.input_negative = 1,
.reference = ADC_REF_EXTERNAL1,
.gain = ADC_GAIN_1,
.acquisition_time = ADC_ACQ_TIME(ADC_ACQ_TIME_TICKS, 0)
};
const struct adc_sequence seq = {
.options = NULL,
.channels = BIT(0),
struct adc_sequence seq = {
.buffer = &buffer,
.buffer_size = sizeof(buffer),
.resolution = ADC_RESOLUTION,
.oversampling = 0,
.calibrate = 0
};
if (!device_is_ready(lmp90100)) {
if (!adc_is_ready_dt(&ch_cfg)) {
LOG_ERR("LMP90100 device not ready");
return 0;
}
err = adc_channel_setup(lmp90100, &ch_cfg);
if (err) {
err = adc_channel_setup_dt(&ch_cfg);
if (err != 0) {
LOG_ERR("failed to setup ADC channel (err %d)", err);
return 0;
}
err = adc_sequence_init_dt(&ch_cfg, &seq);
if (err != 0) {
LOG_ERR("failed to initialize ADC sequence (err %d)", err);
return 0;
}
while (true) {
err = adc_read(lmp90100, &seq);
if (err) {
err = adc_read_dt(&ch_cfg, &seq);
if (err != 0) {
LOG_ERR("failed to read ADC (err %d)", err);
} else {
resistance = (buffer / (double)ADC_MAX) * BOTTOM_RESISTANCE;
resistance = (buffer / adc_max) * BOTTOM_RESISTANCE;
printf("R: %.02f ohm\n", resistance);
printf("T: %.02f degC\n",
rtd_temperature(RTD_NOMINAL_RESISTANCE,