mirror of https://github.com/RT-Thread/rt-thread
118 lines
4.0 KiB
C
118 lines
4.0 KiB
C
/* Copyright 2020 Canaan Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <rtthread.h>
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#include <rtdevice.h>
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#include <stdlib.h>
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#include "../interdrv/adc/drv_adc.h"
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#include "utest.h"
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/*
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* 测试 ADC 驱动的读操作
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* 1. 查找 ADC 设备。
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* 2. 启用 ADC 设备。
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* 3. 启用每个 ADC 通道并读取其值。
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* 4. 验证读取的值在预期范围内。
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* 5. 禁用每个 ADC 通道并验证读取值为 0。
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*
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* 本测试基于 01Studio 开发板，该开发板自带排针，并引出 SoC 的以下 4 个 ADC 通道
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* 板级排针编号 | SoC 的 ADC 通道编号 | 输入电压范围
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* -------------+---------------------+-------------
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* 32 | ADC0 | (0 ~ 3.6V)
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* 36 | ADC1 | (0 ~ 3.6V)
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* 38 | ADC2 | (0 ~ 1.8V)
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* 40 | ADC3 | (0 ~ 1.8V)
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* SoC 的 ADC 通道默认只支持最大 1.8V 的输入电压，对于 ADC0 和 ADC1 通道，开发板
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* 通过增加功放将最大支持电压提升到 3.6V（而且同样采用了分压机制，导致实际 ADC
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* 通道的输入电压只有板级排针电压的一半）。
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*
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* 测试时注意连接输入的最大电压不要超过额定值，否则可能会损坏 ADC 通道。
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*
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* 另外注意这个adc 只有 12bit，所以读取的值范围是 0 ~ 4095
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*
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* 具体测试最大 1.8V 的 ADC 通道（譬如 38/40）时，可以自己通过两个 10K 欧姆的电
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* 阻将模拟输入从 3.3V 分压（将可调电阻调制最大时万用表实测 A 点电压为 1.69V 左右）：
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* +----------+ +---------------+
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* 3.3V ----| 10K 欧姆 |----| 可调 10K 欧姆 |---- 接地
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* +----------+ +---------------+
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* A
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* |
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* ADC2/ADC3
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*
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* 具体测试最大 3.6V 的 ADC 通道（譬如 32/36）时，可以直接引入 3.3V。
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* +---------------+
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* 3.3V --------------------| 可调 10K 欧姆 |---- 接地
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* +---------------+
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* A
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* |
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* ADC0/ADC1
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*/
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static void test_read(void)
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{
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int i;
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rt_err_t ret = RT_EOK;
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rt_uint32_t value, vol;
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rt_adc_device_t adc_dev;
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adc_dev = (rt_adc_device_t)rt_device_find(K230_ADC_NAME);
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uassert_not_null(adc_dev);
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ret = rt_adc_enable(adc_dev, 0);
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uassert_int_equal(ret, RT_EOK);
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for (i = 0; i < 4; i++)
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{
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ret = rt_adc_enable(adc_dev, i);
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uassert_int_equal(ret, RT_EOK);
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value = rt_adc_read(adc_dev, i);
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/* 转换为对应电压值,对应 12 位 ADC 最大值 4095, 内部基准最大电压值 1.8V，数据精度乘以 100 保留 2 位小数 */
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vol = value * 180 / 4095;
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if (i == 0 || i == 1)
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vol = vol * 2; /* ADC0/ADC1 分压后实际电压是输入电压的二分之一 */
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LOG_I("ADC chan[%d] read value: %d, calculated voltage is: %d.%02dV\n",
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i, value, vol / 100, vol % 100);
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}
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for (i = 0; i < ADC_MAX_CHANNEL; i++)
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{
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ret = rt_adc_disable(adc_dev, i);
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uassert_int_equal(ret, RT_EOK);
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value = rt_adc_read(adc_dev, i);
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uassert_int_equal(value, 0);
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}
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return;
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}
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static rt_err_t utest_tc_init(void)
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{
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return RT_EOK;
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}
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static rt_err_t utest_tc_cleanup(void)
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{
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return RT_EOK;
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}
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static void testcase(void)
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{
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UTEST_UNIT_RUN(test_read);
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}
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UTEST_TC_EXPORT(testcase, "adc", utest_tc_init, utest_tc_cleanup, 100); |