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Topic: Arduino not working with shield plugged in (Read 564 times) previous topic - next topic

cblindsey3

Hey, first forum post in a while. I've been developing an Arduino shield that will include a sn754410 motor driver and power buses for sensors. I tested it out just doing point to point soldering. I only actually hooked up the motor driver and some of the sensors, but I had no problem making a few simple robots (obstacle avoidance, line-following, etc.).

I got a prototype shield manufactured from China. I did the design in Eagle and it looked like everything was working. After assembling it and plugging it into the Arduino, the onboard LED dims. Now it is starting to turn off when I plug the board in. It seems like the Arduino is working fine.

This is my first shield, so I've been trying to learn more and troubleshoot the design, but wanted to ask if anyone has had any similar problems or any ideas?

Thank you a ton!!

spycatcher2k

The shield you want to keep secret has a design flaw!

Thats all I can tell you with the information you have supplied.

What about a schematic for starters?
Mrs Drew
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http://www.uk-pcb.co.uk - UK PCB Fab Company
I will design & code for you, but I will also charge you (PM me)
If you don't like my answers, realize : I'm not being cheeky, I'm Just trying to prompt you to use your own brain/google etc.

cblindsey3

Sorry about forgetting that. Here's a screenshot of the Eagle schematic. Basically there is a row of male header pins on the that connect to the Arduino, then another row next to them on the top side of the board. For the analog pins and D4-7 there are also ground and power buses. Pins 0 and 1 are set up for a bluetooth module (hc-06 or 5, the 4 pin one). It has a voltage divider to give ~3.3V. Pins D2 and D3 and hooked up for an HC-SR04 ultrasonic rangefinder. The motor driver connects to D8-13. The header up top is for an OLED screen and hooks up to D4-7.

spycatcher2k

Looks like you're getting the 5V feed from the Arduino for the motors? If you are, then thats the issue, the motors should have their own power supply. Also, where are the Capacitors for the driver chip?
Mrs Drew
-=-
http://www.uk-pcb.co.uk - UK PCB Fab Company
I will design & code for you, but I will also charge you (PM me)
If you don't like my answers, realize : I'm not being cheeky, I'm Just trying to prompt you to use your own brain/google etc.

cblindsey3

On my first prototype (just point to point soldering), I had the motor driver powered through the Arduino. Same motors. But I'll change that in the next design to make it more robust.

And I'm not sure about the capacitors for the driver. Do you mean the motor driver? Electronics is my weak point, so I'm probably missing some basic things.

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