Chris
128d42c586
- Added function to read out the display_buffer via USB-Serial - Added basic structure and files for later complete firmware (still in progress) - Added Doc folder with schematic in it - Added Python script and batch file to read out the display buffer and open the image in gimp
116 lines
3.1 KiB
C
116 lines
3.1 KiB
C
/*
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* ADC.c
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*
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* Created: Tue Sep 13 2022 19:51:36
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* Author Chris
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*/
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// ============================================================================================
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// Includes
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#include "Core1_ADC.h"
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#include "hardware/adc.h"
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#include "hardware/irq.h"
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#include "hardware/divider.h"
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// ============================================================================================
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// Defines
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#define YES true
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#define NO false
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#define ANALOG_REFERENCE_mV 3300ul
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#define ADC_INPUT_PIN 29
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// ============================================================================================
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// Variables
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static uint32_t _ADC_Result_Value;
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static uint32_t _ADC_Result_mV;
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const uint32_t _ADC_Result_Num = 11;
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const uint32_t _ADC_Result_Denum = 1;
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const bool _ADC_Result_LowPass = NO;
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// ============================================================================================
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// Function Declarations
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void Core1_ADC_Select_Next_MUX_Channel();
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void Core1_ADC_Set_Mux(uint channel);
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void Core1_ADC_Store_ADC_Result(uint16_t adc_value);
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uint32_t Core1_ADC_Low_Pass_Filter(int current_value, int new_value);
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/*******************************************************************
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Interrupt Service Routines
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*******************************************************************/
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bool ISR_ADC()
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{
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Core1_ADC_Store_ADC_Result(adc_fifo_get());
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}
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/*******************************************************************
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Functions
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*******************************************************************/
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void Core1_ADC_Init()
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{
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_ADC_Result_Value = 0;
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_ADC_Result_mV = 0;
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adc_gpio_init(ADC_INPUT_PIN);
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adc_init();
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adc_select_input(3);
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adc_fifo_setup(
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true, // Write each completed conversion to the sample FIFO
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false, // Enable DMA data request (DREQ)
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1, // DREQ (and IRQ) asserted when at least 1 sample present
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false, // We won't see the ERR bit because of 8 bit reads; disable.
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false // Shift each sample to 8 bits when pushing to FIFO
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);
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adc_set_clkdiv(5999); // One measurement every 0.125ms -> 8 measurements per 1 ms
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adc_irq_set_enabled(true);
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irq_set_exclusive_handler(ADC_IRQ_FIFO, (void *)ISR_ADC);
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irq_set_enabled(ADC_IRQ_FIFO, true);
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adc_run(true);
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}
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uint16_t Core1_ADC_Get_Result_Value(uint channel)
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{
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return _ADC_Result_Value;
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}
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uint16_t Core1_ADC_Get_Result_mV(uint channel)
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{
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return _ADC_Result_mV;
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}
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/*******************************************************************
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Internal Functions
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*******************************************************************/
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void Core1_ADC_Store_ADC_Result(uint16_t adc_value)
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{
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if(_ADC_Result_LowPass == YES) {
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_ADC_Result_Value = (uint16_t)Core1_ADC_Low_Pass_Filter((float)_ADC_Result_Value, (float)adc_value);
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} else {
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_ADC_Result_Value = (uint32_t)adc_value;
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}
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_ADC_Result_mV = ((_ADC_Result_Value * ANALOG_REFERENCE_mV * _ADC_Result_Num) / 4096) / _ADC_Result_Denum;
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}
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uint32_t Core1_ADC_Low_Pass_Filter(int current_value, int new_value)
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{
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// Link: https://kiritchatterjee.wordpress.com/2014/11/10/a-simple-digital-low-pass-filter-in-c/
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const int Beta = 6;
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current_value = (current_value << Beta) - current_value;
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current_value += new_value;
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current_value >>= Beta;
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return (uint32_t)current_value;
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}
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