Goals:

We would like to finalize the FSM we are developing now to determine how we are moving through the watering sequence. The largest contingency on this is how we are determining the optimal watering time based on temperature. We will come to a conclusion on this and Adam will continue to frame the FSM for our final design. Christer will finalize the comparator and be able to record the number of pulses output from the flow sensor that will directly translate to the amount of water being passed through the system. We will both be working on the I2C communication for the temperature sensor as we both will be executing this for the first time.

Work Completed:

Adam

• Continued improvements to watering sequence.
• Implemented a proportional control algorithm to alter the target water amount, based on the difference measured by the moisture sensor.
• Cleaned up code, moved all configuration information to the top, to make it easier to switch from a test mode to real-time.
• Implemented a manual water mode, allowing it to still interface with the automated system. Will only water the targeted amount (for defined moisture level). Allows for manual stoppage.
• Temperature algorithm now uses a series of five data points, determining the temperature gain/loss between each, then makes a decision as to whether or not a cooling trend is located.
• Recalibrated the LCD touchscreen, as well as debounced our button presses so they are accurate and (properly) responsive.
• Further implemented two configurations, so that the system can switch between short timeframe testing and longer real-time use.

Christer

• Changed flow sensor from working with the comparator to being a digital input pin. To accommodate this, an op-amp was added to create a more precise square wave. This input was used to control an interrupt that measures the amount of water dispersed by the tank.
• The assembled flow system was attached to the water tank by screwing it into the valve on the bottom on the tank. To ensure the weight of the solenoid would not pull it from the valve, zip ties were used through holes put through the table to hold most of the weight.

• The screen would display more water was dispersed than was actually let out of the tank due to the momentum of the water in the flow sensor. The logic for updating the flow value was changed to update only when in the state of watering and once we reached our target amount and the solenoid was closed, we would no longer update the water dispensed value.
• Created the User Interface based on design proposal and elements we found useful during testing. The valve state is displayed at the bottom with an indicator if the tank needs water added to it.

Combined

• Tested water flow sensor in test setup for accuracy. Reading was roughly 30ml over expected value.
• Reviewed Design Proposal to ensure constraints were met. Added display information, as well as water moisture threshold.
• Tested in soil. Soil used in testing proved to be difficult to use, due to extremely dry state it started in. Mixed with water, in hopes to produce moisture levels more conducive to further testing.
• Fixed proportional control for water target amounts. We now normalize our error, and change our targeted amount by this percentage, rather than a fixed value.
• Added failsafe to our solenoid valve. Will now only be allowed to stay open for a user-defined amount of time.
• Tested system repeatedly to see how it traverses through the irrigation cycle. System seems fully implemented, however, more confirmation testing is still needed.

Current Challenges:

We are currently testing the system and attempting to identify any bugs. The largest challenge we are facing now is getting consistent dirt conditions for testing. The dirt was very dry when we added it to the containers and did not absorb water. We are letting the containers sit overnight with varying amounts of water to see how they settle. The other challenge we have is determining how we will display our findings in a way that conveys that our system meets the requirements.

Upcoming Goals:

If we find the soil has reached the testing condition that we expect (how saturated the dirt is) then we will test the system in each sample every day this week. Through these trials we hope to confirm the effectiveness of our target water dispensed algorithm, and its reactions to various soil moisture levels above and below desired thresholds. We also intend on running trending temperature trials to observe how the system reacts and ensure algorithm consistency.