.. _program_listing_file_mainboard_Src_peripherals_si8900.c:

Program Listing for File si8900.c
=================================

|exhale_lsh| :ref:`Return to documentation for file <file_mainboard_Src_peripherals_si8900.c>` (``mainboard/Src/peripherals/si8900.c``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   
   #include "peripherals/si8900.h"
   
   #include "error/error.h"
   #include "mainboard_config.h"
   #include "usart.h"
   
   #include <stdlib.h>
   #include <string.h>
   
   bool si8900_ready = false;
   
   bool si8900_init(UART_HandleTypeDef *huart, GPIO_TypeDef *reset_gpio, uint16_t reset_pin) {
       uint8_t recv = 0;
       uint8_t tx   = 0xAA;
   
       bool timeout      = false;
       bool code_receive = false;
       bool code_confirm = false;
   
       HAL_GPIO_WritePin(ADC_SIN_GPIO_Port, ADC_SIN_Pin, GPIO_PIN_SET);
       HAL_Delay(5);
       HAL_GPIO_WritePin(ADC_SIN_GPIO_Port, ADC_SIN_Pin, GPIO_PIN_RESET);
   
       uint32_t time = HAL_GetTick();
   
       HAL_UART_Transmit(huart, &tx, 1, 10);
   
       while ((!code_receive || !code_confirm) && !timeout) {
           HAL_UART_Receive(huart, &recv, 1, 10);
           if (recv == 0x55) {
               if (code_receive) {
                   code_confirm = true;
                   si8900_ready = true;
               }
               code_receive = true;
           } else {
               code_receive = false;
               code_confirm = false;
           }
           HAL_UART_Transmit(huart, &tx, 1, 10);
   
           timeout = (HAL_GetTick() - time) >= SI8900_INIT_TIMEOUT;
       }
   
       if (timeout) {
           error_set(ERROR_ADC_INIT, 0, HAL_GetTick());
           return false;
       }
       error_reset(ERROR_ADC_INIT, 0);
       return true;
   }
   
   bool si8900_read_channel(UART_HandleTypeDef *huart, SI8900_CHANNEL ch, uint16_t *voltage) {
       if (si8900_ready) {
           uint8_t conf = si8900_cnfg_0 | (ch << 4);
   
           HAL_UART_Transmit(huart, &conf, 1, 1);
   
           uint8_t recv, count = 0;
           while (recv != conf) {
               HAL_UART_Receive(huart, &recv, 1, 1);
               if (count++ > 5) {
                   error_set(ERROR_ADC_TIMEOUT, 0, HAL_GetTick());
                   return false;
               }
           }
   
           uint8_t data[2] = {0};
           HAL_UART_Receive(huart, data, 2, 1);
           *voltage = si8900_convert_voltage(data);
   
           error_reset(ERROR_ADC_TIMEOUT, 0);
           return true;
       }
       return false;
   }
   
   uint16_t si8900_convert_voltage(uint8_t adc_hl[2]) {
       // MSB | LSB
       uint16_t dig = ((adc_hl[0] & 0b00001111) << 6) | ((adc_hl[1] & 0b01111110) >> 1);
   
       return ((SI8900_VREF * (float)dig) / 1024) * 100;
   }