Currently Hardware complete, but needing some work for the software.
..when my time permits
Temperature/Humidity Fan controller for my boat; incorporates a voltage sensor so that it can reduce power when the battery is low on energy, and a button so I can trigger a quiet mode.
- DigiSpark Based
- ATtiny85, plenty powerful enough for this application, and with a robust toolchain. It has 6 IO pins & very little extra cruft
- Has a onboard 5v regulator, I can supply it with the battery voltage, and I can power the DHT11 from the 5v line
- Somewhat tricky to flash/develop for, Lack of a uart is a total pain during debug since BitBang serial emulators eat half the memory+
- DHT11 Temperature and Humidity sensor
- Not ideal, something more accurate would be prefered, but this is what I have.
- A DHT22 would be an easy (plug and go) upgrade
- PWM fan control via a high-current logic-level NPN mosfet
- Battery voltage sensing for powersave and shutdown
- A button.. to allow on/off/quiet overrides
The Hardware is complete; it has a case etc. So.. I need to complete the Software side of things now too.
I have working hardware test sketches (see the
VoltageCalibrate.ino: Test and calibrate the Voltage sensor using USB-CDC serial to feedback
SensorReader.ino: Test and relay readings from all sensors;
- Readings are sequentially flashed out in groups using a LED connected in place of the fan
These Sketches have verified my wiring and confirmed the calibration of the resistor divider used to sense the battery voltage.