I am developing an electronic prototype device that will monitor windspeed and direction using an array of air pressure sensors. This prototype will be tested in a wind tunnel. The device will be physically connected by a USB connector to a laptop computer that will display the sensor output and log the sensor readings for later study and analysis.
I have included documentation and links for all the specifications described below.
This project is underway and the work needed here was begun by another Freelance who was unable to compete the project.
First Deliverable: Design 2 small PCBs
The first PCB will hold 3 air flow sensors (I2C) mounted side by side with a 4.7k Ohm pull-up resistor on each sensor's SCL and SDL outputs. The resistors need to be easily hand soldered and the values may need to be changed on occasion so the design will need to accommodate this possibility. The back of the board will have a wire-to-board-connector that will allow the first board to connect to the second board. The connectors should be mounted to minimize the overall profile effect of the wiring. There is an included graphic that shows the height and width alignment of the sensors. The boards should be designed to minimize the height and width dimensions.
The second PCB will hold two Adafruit breakout boards on one side and an Arduino Nano on the other. The USB plug on the Nano should be accessible through a window on the side of the case. Case design is not part of this project. Again, the connectors should be mounted to minimize the overall profile effect of the wiring.
The two boards will be mounted back-to-back in a case such that with spacers and mounting screws they become a single component.
Note: The reason I am asking for this design is that I plan on adding additional electronics in the future. By having the sensors on one board and the electronics on another I can more easily change the electronics without disturbing the sensor board.
Second Deliverable: Modify existing code or create new code that will allow the sensor output to be monitored on an attached computer and the data stream logged in a text file.
The Arduino Nano will be connected to a laptop computer via USB cable. I will need to be able to start and stop data monitoring and logging as needed as well as set the intervals at which the sensor output is delivered to the monitor and log. The log also needs to contain a timestamp.
It is likely that after some usage and testing of the device I might have some software modification requests and would like the programmer to be available for follow-up.
The included schematic was originally designed without using breakout boards. The modifications needed to accommodate the breakout boards are noted on the schematic
3 Omron D6F-PH sensors
- D6F-PH0505AD3 (2)
- D6F-PH0025AD1 (1)
- Datasheet: [login to view URL]
- CAD download: [login to view URL](S(0zupvrm10z0fcrwbzy25vm0b))/[login to view URL]
- Adafruit 2717: TCA9548A - I2C Multiplexer (1)
- Adafuit 395: TXB0108 - 8-channel Bi-directional Logic Level Converter (1)
Arduino Nano (1)
4.7k Ohm resistor (6)
Wire-to-Board-Connectors (as needed)