Mouse code for the MacroRat
Diff: mbed-dev/targets/TARGET_NORDIC/TARGET_NRF5/TARGET_MCU_NRF52832/analogin_api.c
- Revision:
- 18:6a4db94011d3
diff -r f713758f6238 -r 6a4db94011d3 mbed-dev/targets/TARGET_NORDIC/TARGET_NRF5/TARGET_MCU_NRF52832/analogin_api.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed-dev/targets/TARGET_NORDIC/TARGET_NRF5/TARGET_MCU_NRF52832/analogin_api.c Sun May 14 23:18:57 2017 +0000 @@ -0,0 +1,91 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2013 ARM Limited + * + * Licensed 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 "mbed_assert.h" +#include "analogin_api.h" +#include "cmsis.h" +#include "pinmap.h" +#include "app_util_platform.h" +#include "nrf_drv_saadc.h" + +#ifdef DEVICE_ANALOGIN + +#define ADC_12BIT_RANGE 0xFFF +#define ADC_RANGE ADC_12BIT_RANGE + +static void analog_in_event_handler(nrf_drv_saadc_evt_t const *p_event)// type of nrf_drv_saadc_event_handler_t +{ + (void) p_event; +} + +static const nrf_drv_saadc_config_t saadc_config = +{ + .resolution = NRF_SAADC_RESOLUTION_12BIT, + .oversample = NRF_SAADC_OVERSAMPLE_DISABLED, + .interrupt_priority = SAADC_CONFIG_IRQ_PRIORITY +}; + +void SAADC_IRQHandler(void); + +void analogin_init(analogin_t *obj, PinName pin) +{ + ret_code_t ret_code; + + NVIC_SetVector(SAADC_IRQn, (uint32_t)SAADC_IRQHandler); + + ret_code = nrf_drv_saadc_init(&saadc_config, analog_in_event_handler); + MBED_ASSERT(((ret_code == NRF_SUCCESS) || (ret_code == NRF_ERROR_INVALID_STATE))); //NRF_ERROR_INVALID_STATE expected for multiple channels used. + + uint8_t saadcIn = nrf_drv_saadc_gpio_to_ain(pin); + MBED_ASSERT(saadcIn != NRF_SAADC_INPUT_DISABLED); + + obj->adc = ADC0_0; // only one instance of ADC in nRF52 SoC + obj->adc_pin = saadcIn - 1; + + nrf_saadc_channel_config_t channel_config = + NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(saadcIn); //Single ended, negative input to ADC shorted to GND. + + ret_code = nrf_drv_saadc_channel_init(obj->adc_pin, &channel_config); + MBED_ASSERT(ret_code == NRF_SUCCESS); +} + + +uint16_t analogin_read_u16(analogin_t *obj) +{ + int16_t adc_value; + ret_code_t ret_code; + + ret_code = nrf_drv_saadc_sample_convert(obj->adc_pin, &adc_value); + MBED_ASSERT(ret_code == NRF_SUCCESS); + + if (adc_value < 0) + { + // Even in the single ended mode measured value can be {-0}. Saturation for avoid casting to a big integer. + return 0; + } + else + { + return (uint16_t) adc_value; + } +} + +float analogin_read(analogin_t *obj) +{ + uint16_t value = analogin_read_u16(obj); + return (float)value * (1.0f / (float)ADC_RANGE); +} + +#endif // DEVICE_ANALOGIN