Out of Water Turbidity
10 June 2020
In addition to turbidity it would be interesting to test if velocity could be measured using the sensor by tracking the motion of objects on the surface of the water.
The first step is to investigate if the idea is viable. To do this it would be good to gather raw data on what a camera would see when in a drain. From this we will be able to see how turbidity levels affect the image and determine ways to determine to extract the turbidity component using the small processing ability of the ATmega328p or a similar micro-controller.
The ArduCam module was tested as it is likely to form the backbone of the out of water turbidity sensor. Its standard library was downloaded and it was wired to an Arduino Uno on 5V. This worked well, and photos were able to be taken. Next the power supply was changed to 3.3 V. This also worked well and the camera appeared to still be working normally.
When it was attempted to be connected to a BoSL board. It raised the error of not being able to detect the camera. Currently the 8MHz speed of the ATmega on the BoSL board is the suspect. Plugging in the I2C lines of the device in addition to the SPI lines allow the camera to work somewhat on the BoSL board. The connection is unreliable though, and photos will commonly not transmit. It seems that this issue is mostly due to bad quality wires used in the connection. Holding them down while trying to take a photo mostly solves the issue. The baud rate of the serial port was also decreased to 115200.
13 June 2020
Instead of a BoSL board, initially a Arduino MKR zero will be used to connect to the Arduino CAM in the drain. This is because it has an integrated SD card for storing photos, additional processing power, and is much smaller and compact. It also has an RTC which can be used to set the time of the photos.
It was found that the Ardu CAM code compiled on the MKR zero with no adjustments needed. The camera performance was about the same as on the 3V3 BoSL board: some photos were corrupted however it is thought that this is more to do with the cabling than the powering of the device off 3V3 volts itself.
14 June 2020
The SPI clock speed was adjusted on the Arduino MKR zero to get maximum reliability from the ArduCam, it was found that a clock speed of 1MHz provided the optimal stability.
