For my basic application I planned on making an alarm box. When someone opens the box when it’s armed, it will flash lights and make a noise. This would occur until a green button is pressed. A red button will be used for arming the alarm.
I think I would have pulled it off if I designed my circuit beforehand. However I was able to have an alarm triggered and and make lights and speaker cycle on and off. I made a lot of errors with running the wires in the wrong direction or forgetting to power the breadboard.
For the past week I worked on catching up with the lab assignments. This is the button switcher with LEDs in parallel.
The next lab involved a potentiate and LED to simulate variable voltage.
Then I built the Servo variable resistor circuit. That was fun and noisy.
Now the speaker with photoresistor.
The only issue I had was breaking off the lead wire in a Arduino pin socket. Luckily that led to ground. I also got to use a soldering iron to connect the wire leads to my speaker.
Now hopefully I can work on an application of these for tomorrow’s class…
My project for this week was supposed to be a RGB LED controlled by three sensors (FSR, potentiometer and a ping) for each color. I spent such a large amount of time troubleshooting the inputs that I didn’t get to touch the led portion. I should have started this much earlier but I misjudged the time I needed to complete assignment #3.
It could have been exhaustion but I was trying to hook up a digital ping sensor as a variable resistor. I didn’t have my force sensor properly grounded. My pot wasn’t giving a linear progression of numbers until I did something that I now can’t remember (but still a narrow range).
I think what’s left for me to do is remap the values to emulate brightness with a blink function…. maybe I should buy a 2nd RGB LED.
The interactive device I decided to monitor is a parking meter. The physical function of a parking meter is to take your money and return you a talisman. This talisman protects you from receiving cursed objects on your windshield. The cursed objects actually cost more money to get rid of. It behooves you to pay to get a talisman.
A NYC parking meter has one purpose as far as civilians are concerned. That is to allow people to park their motorized vehicles in designated parking areas during the times listed on street signs. I would assume a person selects the amount of time they would like to park and then enter a form of payment to get a receipt to place on your dashboard.
However upon closer inspection, it doesn’t work that way. First I am not sure how many blind people use this machine, but that edge case is not covered here. There is an audio jack that I assume outputs some sort of audio instructions. The language button, which is a different shade of grey than the audio jack, would probably cycle through other common languages in NYC for the audio.
A user walks up to the device and will have to enter there credit card or start inserting $1 or 25 cent coins. I’ve noticed people with credit cards, if they don’t leave the card in the machine for a few seconds it won’t work. This could be a result of the new chips that recent cards feature. However there is no indication to leave the card in the slot until prompted. Some people waited longer than others for it to verify their cards.
After that it seemed pretty intuitive. You increment the time you want (up tot he max) and pay the related price. NYC included a max/time button, which will select the highest time allowed. This actually save you 3-7 clicks depending on the increment scale. After the time is selected you will print the receipt or choose to cancel everything. A downside to this is that you have to pay per half hour, so if you 15 minutes before the free parking period you still pay for the entire half hour.
While it’s nice to accept coins, it’s cumbersome and not useful unless the user planned ahead. I saw someone have to go back to their car to harvest some coins from the car. I would say the user interface is designed well. They used contrasting colors on buttons so you’re less likely to make a mistake pressing one over the other. They also made the Print button big and green.
Image credit: Pureandapplied.com
The quickest task to do is entering coins and pressing the Print button. The longest possible task ignoring the audio function would be to use a credit card and increment to the max. Then press the Print button. There’s usually no line and only one person waiting if there is. Ignoring the guy running to his car for coins, I would say it’s possible to complete the transaction in under 15 seconds. The credit card method is around 20-30 seconds.