Build, Test, Document
Table of Contents
The building of the DAQ system has been separated into 2 revisions. The first revision is a working prototype. This is for proof of concept and to begin testing higher level functions such as wireless connectivity or file recovery. The second revision will take the prototype and make it better. This means it will be in a better housing, more portable, nicer peripherals. Essentially the second revision will look like a product that has been bought off the shelf. Revision 2 will consist of 2 models as well. One model will be a "deluxe" model with a LCD screen, LED indications, and wireless capability. The other model will be a "bare-bones" model that will be smaller, shock-proof, water-proof and battery powered. Both will have magnets to allow them to be attached with ease to systems already in place. As of this point, the prototype has been completed and revision 2 has begun.
Build, Test, and IntegrateThe prototype has been completed and Revision 1 is done. Seen below are some pictures of the internals and the outside of the box for Revision 1.
The Revision 1 prototype runs on a 9V adapter plugged into the wall. It can record pressures up to 3000 PSI, displacement up to 12 inches and temperatures up to 1250 degrees Fahrenheit. An 8GB internal SD card is used to record the data samples. Currently samples are recorded once every 2 seconds however this sample rate can be adjusted to whatever the user prefers. The 4 LED's are used as threshold warnings and a running light to signal data is being captured. The thresholds can also be adjusted to whatever the user prefers. The wireless capability for this revision was integrated very minimally but proof of concept was achieved. Whenever a high threshold was reached for pressure, temperature or displacement the DAQ would send out an email to warn of a threshold event. In the next revision this wireless capability will be expanded to include live monitoring of temperature, pressure and displacement through an internet browser. Seen below is a circuit diagram for the internals of the prototype
A copy of the code used for the prototype in Revision 1 can be found at the link below. This code will be cleaned up and added to for the product that will be created in Revision 2. This code basically sets up a file to log to, measures all three sensors and then logs the data to the file that was previously created. While this is happening, the code also writes to the LCD display with the sensor values and constantly monitors for threshold events. In the event of a threshold being met, an LED will light up and an email will be sent to the customer.
This revision was considered a success for a proof of concept. Data was collected, all the sensors worked within an acceptable range of accuracy, wireless concepts were explored. However a few issues were raised that will be corrected in the next revision. The wiring is messy currently and will be cleaned up in the next revision. As well, the SD card is currently internal and the lid needs to be removed to access it. This is a huge usability issue and will be remedied in the next revision by making the card assembly mounted to the outside of the box. The case material selected for the prototype was plastic and a harder, more sturdy poly-carbonate will be used for the next revision as well.
Revision 2 is partially complete at this point. Revision 2 consists of two different models of data-loggers being created. One data-logger is a barebones type model that will simply log the temperature, pressure and displacement values to a storage device. The other model is a more advanced type data-logger that will consist of the same data-logging principle but will also have an LCD screen, wireless capability, and a number pad to allow for user input. The image below shows the Rev 2 data-logger in their current state.
As can be seen in the image above, the more advanced model is on the left and the barebones model is on the right. The left model has an LCD screen and number pad located on the top of the box along with LED warning indication lights. The model on the left simply consists of 2 buttons and an LED light to check if it is running. At this point the internals of the barebones model have been assembled and the code is currently being written. For the advanced model the screen, number pad and wireless internals have been wired and the code is also being developed for that model. Further pictures and codes used in the Rev 2 models are to follow as they become available.