Files
drybox-core/src/main.c

137 lines
3.6 KiB
C

#include "common.h"
#include "bus/usart.h"
#include "bus/mosfet.h"
#include "bus/pwm.h"
#include "bus/i2c.h"
#include <avr/interrupt.h>
// TODO: Implement optional CRC8 sensor measurement check.
// TODO: Either implement software PWM for the FAN03 timer
// (which will be quite complicated) or pick a chip with
// more than two 16-bit PWM outputs like the ATmega328PB.
// https://www.mikrocontroller.net/articles/Soft-PWM
// TODO: Check if FAN02 is receiving the right frequency.
// TODO: Write an improved command parser (low priority).
// TODO: Proper error handling and recovery (after testing).
static int Init(void)
{
// MOSFETS control things like the heating element
// so they are the highest priority to initialize
// to a default state via MOS_Init().
MOS_Init();
// The serial interface is required for output
// functions like Info() and Error() and it uses
// IRQs, so we need to initialize it as soon as
// possible and make sure to enable interrupts.
USART_Init();
sei();
Info("Initializing...");
// The watchdog timer is clocked from a separate
// on-chip oscillator which runs at 1 MHz. Eight
// different clock cycle periods can be selected
// to determine the reset period. If the reset
// period expires, the chip resets and executes
// from the reset vector.
// The update loop must call WDT_Reset to reset
// the timer, kind of like a dead man's switch
// allowing us to detect infinite loops and any
// other error that halts execution.
if (WDT_HasTriggered())
Info("Unexpected system reset.");
WDT_Enable();
WDT_SetTimeoutFlag(WDT2000); // 2 seconds
// There is a possiblity to use interrupt signals
// for I2C communication but only as one large
// branching routine for the whole I2C system.
// The blocking approach used right now is fine.
I2C_Init();
PWM_Init();
MOS_Enable(MOS03);
// MOS_Disable(MOS01);
// Only FAN01 and FAN02 are receiving the correct
// frequency (25 KHz) right now. The 16-bit timer on
// the ATMega32A has two outputs so it would require
// software PWM to have a variable frequency on PD7.
// A simple implementation will take up around 30-50
// percent of CPU time. Faster approaches are quite
// complicated so it might be worth it to switch to
// something like an ATmega328PB.
PWM_SetValue(FAN01, 50); // Fan Peltier Hot side
PWM_SetValue(FAN02, 50); // Fan Peltier Cold Side
// PWM_SetValue(FAN03, 20); // Fan Heating
// The I2C_SetChannel command changes the channel
// setting of the PCA9546 I2C multiplexer. Any
// command after it will be sent to the device
// listening on that channel.
I2C_SetChannel(AHT01);
I2C_AHT20_Init();
I2C_SetChannel(AHT02);
I2C_AHT20_Init();
I2C_SetChannel(AHT03);
I2C_AHT20_Init();
return 0;
}
static void Update(void)
{
float temp[3], rh[3];
float adct[3];
Info("Reading sensor values...");
I2C_SetChannel(AHT01);
I2C_AHT20_Read(&temp[0], &rh[0]);
I2C_SetChannel(AHT02);
I2C_AHT20_Read(&temp[1], &rh[1]);
I2C_SetChannel(AHT03);
I2C_AHT20_Read(&temp[2], &rh[2]);
Sleep(200); // FIXME: Poll config register until BIT(15) == 1
adct[0] = I2C_ADS1115_ReadThermistor(ADS01);
Sleep(200); // FIXME: Remove me - see above.
adct[1] = I2C_ADS1115_ReadThermistor(ADS02);
Sleep(200); // FIXME: Remove me - see above.
adct[2] = I2C_ADS1115_ReadThermistor(ADS03);
Info("TEMP0=%.2fC, TEMP1=%.2fC, TEMP2=%.2fC", temp[0], temp[1], temp[2]);
Info("ADCT0=%.2fC, ADCT1=%.2fC, ADCT2=%.2fC", adct[0], adct[1], adct[2]);
Info("RH0=%.2f%%, RH1=%.2f%%, RH2=%.2f%%", rh[0], rh[1], rh[2]);
}
int main(void)
{
Init();
for (;;) {
WDT_Reset();
Update();
WDT_Reset();
Sleep(1000);
}
return 0;
}