Shield Shield - Blinking LED problem

Hey Guys,

I’m new to electronics so please bear with me :smile:

I’m not sure if it’s me or if there is an issue with my shield shield, but I cannot get a blinking led to work using any of the digital pins (0-7, and yes I update the code when testing the pins) on the shield shield. If I plug the spark into a breadboard and connect the led to the digital pin it works without any issues. It’s like power is not routing through the digital pins on the shield shield.

If I wire the led directly to GND and 3V3 on the shield shield, it works.

The shield shield is using a 7v 2a power supply

Here is the code:

// Define the pins we're going to call pinMode on
int led = D4;  // You'll need to wire an LED to this one to see it blink.
int led2 = D7; // This one is the built-in tiny one to the right of the USB jack

// This routine runs only once upon reset
void setup() {
  // Initialize D0 + D7 pin as output
  // It's important you do this here, inside the setup() function rather than outside it or in the loop function.
  pinMode(led, OUTPUT);
  pinMode(led2, OUTPUT);

// This routine gets called repeatedly, like once every 5-15 milliseconds.
// Spark firmware interleaves background CPU activity associated with WiFi + Cloud activity with your code. 
// Make sure none of your code delays or blocks for too long (like more than 5 seconds), or weird things can happen.
void loop() {
  digitalWrite(led, HIGH);   // Turn ON the LED pins
  digitalWrite(led2, HIGH);
  delay(1000);               // Wait for 1000mS = 1 second
  digitalWrite(led, LOW);    // Turn OFF the LED pins
  digitalWrite(led2, LOW); 
  delay(1000);               // Wait for 1 second in off mode

Do I have to add anything to the code do use the digital pins on the shield shield?

Have I missed something obvious? :slight_smile:



Did you solder the led to the digitalpin pad or simply poked it?

I would use a multimeter to check and see if there’s a voltage on the Digital pins :wink:

Hey @kennethlimcp,

Thanks for your response.

No I just popped in some jumper cables which then connects to a breadboard and then the led. It works via an Arduino Uno so I’m happy with the wiring.

Believe it or not I have never used a multimeter :frowning:. I’ll have to go buy one and check. I’m sure I’ll find some decent youtube vids.

I hope the shield shield is not broken as I’ve only had it a few weeks and this is the first time I’ve found the time to test it :frowning:

It’s probably not broken but poor connectivity since the contacts are kind of crude.

You can try to touch the digital pin with the jumper wires :wink:

aaa ok, getting somewhere, thanks.

If i touch pin 7 below the header pin, it seems to work and now when I plug it into the header it’s working, although the light is very dim and alternates in intensity. None of the other digital pins work though.

If I touch the the digital pin on the spark itself, it lights up beautifully, the same with pin 4.

1 Like

Hello Timothy,
Based on your last observation it seems it could be either a faulty buffer chip (TXB0108PWR) that translates the voltage levels (3.3V <–> 5.0V) or a bad solder joint. Is it possible for you to take a close up picture of the chip on the board and post it here? And if you have access to a soldering iron, retouching the headers and the chip legs should fix the problem. I’m sorry for the trouble caused!



I’m really sorry for the late reply.

Here are a couple of pictures, hopefully they’re what you’re referring to:

To be honest I’m not that confident with a soldering iron :frowning: I’m rather new.