PCB project doesn't work on the PCB but on the breadboard it does. I need guidance on how to find out what's wrong.

Thread Starter

stryker1803

Joined Dec 15, 2022
13
Hello guys, in the past few weeks, I've been working on a project called the Knight Rider on Arduino. I first started doing this project for a Microcontroller class that I took then I decided that I wanted to learn how to use Altium Designer so I concluded that a good idea would be to take this project and design a PCB for it. Long story short I did the project I created the component footprints and schematics and finally the PCB. I got to solder the components, but the project doesn’t work. I don’t know if I did something wrong with the circuits or the Polygon pour. I ran some tests on the breadboard and it works but on the PCB it doesn’t. Any help would be appreciated.
 

Attachments

djsfantasi

Joined Apr 11, 2010
9,186
You didn’t mention programming the MCU. Was it pre-programmed before soldering into the board?

It might be useful to include a programming header on your PCB to allow you to change or update the code. Or use an IC socket do it can be programmed before inserting on your PCB.
 

Thread Starter

stryker1803

Joined Dec 15, 2022
13
You didn’t mention programming the MCU. Was it pre-programmed before soldering into the board?

It might be useful to include a programming header on your PCB to allow you to change or update the code. Or use an IC socket do it can be programmed before inserting on your PCB.
Yes, I pre-programmed the Atmega328P U from the breadboard with the Arduino Reset, RX and TX pins connected to it in the breadboard and loaded the code into it. I removed the chip and plugged it into a 28 Pin IC socket that I soldered into the PCB. Don’t know why it isn’t working.
 

WBahn

Joined Mar 31, 2012
30,294
Hello guys, in the past few weeks, I've been working on a project called the Knight Rider on Arduino. I first started doing this project for a Microcontroller class that I took then I decided that I wanted to learn how to use Altium Designer so I concluded that a good idea would be to take this project and design a PCB for it. Long story short I did the project I created the component footprints and schematics and finally the PCB. I got to solder the components, but the project doesn’t work. I don’t know if I did something wrong with the circuits or the Polygon pour. I ran some tests on the breadboard and it works but on the PCB it doesn’t. Any help would be appreciated.
Clearly you C3 isn't soldered in properly.

You aren't giving use nearly enough information to really help you. We can't examine your PCB to see if there's anything obvious that doesn't match the schematic because, well, you haven't provided a schematic.

Also, "isn't working" isn't a very good starting point for diagnosing things. How isn't it working? How is it behaving/misbehaving? What is it doing that is shouldn't? What is it not doing that it should?

What steps have you taken track down possible errors?

Do you have an unpopulated board? Have you verified that the planes aren't shorted to each other before you even put a component in? Have your run continuity checks to verify that exactly those pins that are supposed to connect to one of the planes actually do? With the populated board, what is the supply voltage when it is powered up? How much current does it draw when powered up? How much does the breadboard version draw? What is the actual clock frequency at the input of the clock pin on the micro on both the PCB and the breadboarded versions?
 

Thread Starter

stryker1803

Joined Dec 15, 2022
13
Clearly you C3 isn't soldered in properly.

You aren't giving use nearly enough information to really help you. We can't examine your PCB to see if there's anything obvious that doesn't match the schematic because, well, you haven't provided a schematic.

Also, "isn't working" isn't a very good starting point for diagnosing things. How isn't it working? How is it behaving/misbehaving? What is it doing that is shouldn't? What is it not doing that it should?

What steps have you taken track down possible errors?

Do you have an unpopulated board? Have you verified that the planes aren't shorted to each other before you even put a component in? Have your run continuity checks to verify that exactly those pins that are supposed to connect to one of the planes actually do? With the populated board, what is the supply voltage when it is powered up? How much current does it draw when powered up? How much does the breadboard version draw? What is the actual clock frequency at the input of the clock pin on the micro on both the PCB and the breadboarded versions?
I just checked and I think the problem lies in the C3, as you guys stated I put the capacitor in series to the VCC polygon pour thinking that it would work but it didn't. I’m going to ground that cap and put one of his legs in series to the VCC of the chip and remove the VCC polygon pour. That would work. I know this is the problem because I took a jumper cable and connected it from the positive side of the header pins to the VCC of the chip and LEDS light up!!
 

Attachments

Top