I have gotten stuck on Lab 4, of the PropStick USB PE kit. One of the programs is to have the LED on P4 light up when the pushbutton connected to P23 is activated. LED on P5 should light when the button on P22 is activated. LED on P6 should light when the button on P21 is activated. But, only the LED on P6 lights up with its corresponding button. The other 2 LED's just stay light up the whole time. Im not very good with schematics right now, but I'm positive I wired it right.
The code is:
PUB ButtonLed
dira[6..4] := %111
dira[21..23] := %000
repeat
outa[6..4] := ina[21..23]
I still have no clue why it wont work right. I have attached some pictures of the wiring and schematic. I would appreciate the help. Thanks, Zekk
Thanks Chris, but unfortunely I have tried that and it doesnt do much good. It just change it so the Leds on P5 and P6 light up. But the Led on P4 does light when the button on P21 is activated. I do thank you for the compliment though. I will try to keep figuring out what is wrong. I may to skip over it for now and continue. Who knows, maybe I will wake up the next morning and know why.
Thanks Chris, but unfortunately I have tried that and it doesn’t do much good. It just change it so the LEDs on P5 and P6 light up. But the Led on P4 does light when the button on P21 is activated. I do thank you for the compliment though. I will try to keep figuring out what is wrong. I may to skip over it for now and continue. Who knows, maybe I will wake up the next morning and know why.
This might be nothing, but it seems to me that there are missing a connection between the two power rails. Many of these breadboards have split the power rails and I have connected them with a permanent connection on my boards.
It also seems to me that you are not using black wire as ground and red wire as power. You should try to get in the habit of using the wire color consistent as that makes the layout easy to read.
I hope you find your solution. Good troubleshooting starts by being thorough and testing your assumptions. I know you say that you have this wired up right, but I would like to know if you have verified the voltage at the input and output of each button circuit (P21, P22, and P23).
For example, if those buttons work like the similar ones I have, the top two contacts (left and right) are always connected. Same for the bottom two (left and right). So when you press the button, it connects all four pins. I’ve shown this in the picture below with red lines indicating the contacts that are always connected.
Based on your picture, only your bottom button is connected correctly. The 100 ohm resistor needs to be directly across the button from the 10k resistor. The +voltage supply needs to be diagonally across from the 100 ohm resistor.
The way you have it now, the two top buttons will be feeding +voltage to their 100 ohm resistors all the time, regardless of whether the buttons are pushed or not.
Well, according to my diagram which shows me how to wire the power for the board. It says I only need that wire for it. I actually once mixed those wires and relized I switched them around. I had to check the diagram a few times to make sure I had all the right wires in the right place.
You have solved my problem. Thanks you very much. I wired it like you said and added that wire to the power strip for ground. That had been my problem before. I hadnt added that wire there. Which is why the rest wouldn’t work. So thank you very much. Now I can continue.
Listen, sometimes documentation is wrong or incomplete. You have to use your own head and not follow instructions blindly without understanding.
Look at your schematic. Those 10k resistors need to be connected to ground. You need to check and see if they are, not just guess or assume. Some breadboards connect those power rails, and some do not. Use a multimeter, and verify what you are seeing against what should be there.
Geir and I have identified some things for you to check and/or correct. Please give it a try and let us know what you find.
