fixed/tweaked again the rules

adjusted rules: wait longer for oxygen sensor to be heated up and give ...

it more time to heat up, time out the sensor heater after 15 mins if
there does not seem to be a fire, switch the heater on if it is off and
not faulted and it seems obvious there is a fire burning, decreased the
min. temp the oven is expected to reach to 700°C, consider the fire
burning if it either reached that min. temperature or if lambda is below
2.

added fire dir "burning" and "warm_start", initial impl. of rules for ...

warm start, use constants in rules, added assertNull and assertNotNull

allow switching to 8 MHz, use bit shift instead of division to calculate ...

time, poll button every 32 ms instead of 16 ms, some other small
improvements, adjusted tests

use enums instead of constants, rename "heating" to "heater"

added/improved/fixed some tests, some related small fixes and ...

improvements

don't measure, update and display lambda when heating is not ready since ...

these measurements are useless

increment timebase and update display according to simulation data

moved formatting of time to module interrupts

compensate ADC non-linearity, update measurements also when heating is ...

off, added some comments

fixes and improvements for oxygen sensor heating control

experimental implementation of rules to notify about certain conditions ...

during burndown

refactored/renamed module "usart", use own implementation, added test, ...

updated comments, some cleanup

- use size_t ...

- added tests
- some small improvements

- made function parameters readonly ...

- types with capital first letter
- updated comments and documentation

- use program space for unit test instances instead of data space ...

- "private" variables static
- removed updateDisplay()
- renamed some functions

finally updatePending is set at the right time so display is always ...

updated immediately

corrected wrong value in lambda lookup table

moved ADC and LCD pin constants to pins.h

- Use SLEEP_MODE_IDLE instead of SLEEP_MODE_ADC (and ...

loop_until_bit_is_clear(ADCSRA, ADSC)) since it will not corrupt USART
RX/TX data and click the beep
- Use shorter commands to for less typing and memory
- Command to enable/disable logging
- Use atoi() instead of strtol() since it requires less flash and should
be sufficient here

- Set and cancel alerts ...

- Display text
- Receive USART data
- Simulation by sending measurement values via USART
- Added some commands like enabling and disabling simulation
- Some refactoring and renaming of functions
- Comments missing
- Tests missing

- Put ADC pins in sensors.h ...

- Added comments for pin assignment in "official" diagram

Added a simple "menu" (display options that show min and max ...

measurements since last start/reset) accessible through a pushbutton
triggering an PICINT interrupt. Added two modules "interrupts" and
"display", refactored code and added some tests.

Do not divide the oxygen sensor voltage by 11 before looking up the ...

lambda value but multiply the voltages in the lookup table by 11

- Smarter way of calculating moving average and avoiding rounding errors ...

- Use unsigned integers for voltages from ADC since they can never be
negative

Formatting

- Added lambda range "Okay" ...

- Round lambda value shown on display to precision 1
- Log lambda value x1000 (max. precision)
- Remove logging of realtime measurements
- Added tests, updated some comments

Removed license, really not necessary for such a project

- Set ADC clock prescale to 8 (125 kHz at 1 MHz CPU clock) ...

- Let measure() return measurement that can be called to display()
instead of measure() calling display() (for testability)
- Removed semicolons from #defines
- Include stdbool.h and use bool instead of uint8_t
- Added tests
- Some formatting, comments

- Multiply values by 16 for better precision calculating the average ...

- Added/improved some related tests