diff --git a/calibration_and_testing/exp01_sensor_calibration.md b/calibration_and_testing/exp01_sensor_calibration.md index 9cd8776..96bc86a 100644 --- a/calibration_and_testing/exp01_sensor_calibration.md +++ b/calibration_and_testing/exp01_sensor_calibration.md @@ -16,28 +16,40 @@ necessary to adjust the user experience of the final device. ## Methodology -1. Prepare the code. Three versions of the code will be used raw, slightly +1. Prepare the sensor. The power input should come from the 5V output of the + board. This is important since different voltage inputs to the sensor will + alter the obtained measurements for an identical humidity. +2. Prepare the code. Three versions of the code will be used raw, slightly smoothed and heavily smoothed. - Raw version outputs the sensor's measurement to the serial port in real-time, unfiltered. - The slightly smoothed version will take 10 measurements with 50ms of delay between each and return the mean. - - The heaviliy smoothe version will take 100 measurements with 50ms of - delay between each and return the mean. -2. Prepare the soil + - The heavily smoothe version will take 100 measurements with 50ms of delay + between each and return the mean. +3. Prepare the soil - In a small recipient (weight: 80g), place 200g of soil. - Let it dry for X days (collection on 24/10/2022) to obtain the driest possible soil. -3. The next steps will be performed repeteadly by adding 10ml of water to the +4. The next steps will be performed repeteadly by adding 10ml of water to the soil at each step. Start by first measuring the completely dry-soil. Ensure that the water is distributed uniformly across the soil. For each amount of water up to a max of 200ml, and for each version of the code: - Obtain measurements from the sensor. If the measurement is unstable, record the observed range and the most frequent value. -4. Finally, obtain measurements in a glass of pure water, with no soil at all. +5. Finally, obtain measurements in a glass of pure water, with no soil at all. ## Results -Make line chart with measurement by hydration level. +See file `exp01_sensor_calibration.ods`. -## Conclusions \ No newline at end of file +## Conclusions + +The results where a bit dissapointing. The sensor signal was clearly moving +when the dry soil received the first 10ml of water. But, from that point on, +the next additions of water barely modified the returned signal. Eventually, +there was no significant change in the sensor values. This is showing a +sensitivity way below what I was expecting. + +I have been reading about some modifications in the circuit to improve the +accuracy of the sensor. I'll design another experiment to try them out. \ No newline at end of file diff --git a/calibration_and_testing/exp02_sensor_calibration_with_aref.md b/calibration_and_testing/exp02_sensor_calibration_with_aref.md new file mode 100644 index 0000000..522dae8 --- /dev/null +++ b/calibration_and_testing/exp02_sensor_calibration_with_aref.md @@ -0,0 +1 @@ +https://makersportal.com/blog/2020/5/26/capacitive-soil-moisture-calibration-with-arduino \ No newline at end of file diff --git a/requirements.md b/requirements.md index 56daf7c..87ad5b4 100644 --- a/requirements.md +++ b/requirements.md @@ -20,8 +20,8 @@ way possible._ - The device operates with one or two 9V batteries. - The device comes with a QR code linking to the minimal instructions for setup and operation. -- Reading-time not accounted for, the device can be installed in under a - minute. +- Documentation reading time not accounted for, the device can be installed in + under a minute. ## Operation acceptance criteria @@ -29,4 +29,5 @@ way possible._ doable without any sort of equipment. - The device can run for at least 6-months without a battery change (assuming the starting point is two fully loaded 9V batteries). +- The device can be turned off and on without any special equipment. - \ No newline at end of file