Second motor shield not registering after scraping resistor

[Fisu]

I want to use two motor shields. I've followed the advice in this topic http://forum.tinycircuits.com/index.php?topic=1594.0. I've scraped the black coating from resistor R1 as much as I can. The resistance across R1 is now 3.31 kOhm (the resistance across an unscraped R1 is 1 kOhm) My code looks something like this:

Code: [Select]

MotorDriver motor(0);
MotorDriver motor1(1);
const int maxPWM = 10000;

void setup() {
  if(motor.begin(maxPWM)){
      Serial.println("Motor driver 0 not detected!");
      while(1);
  }
  if(motor1.begin(maxPWM)){
      Serial.println("Motor driver 1 not detected!");
      while(1);
  }
}

When I run this, I see "Motor driver 1 not detected!". Have I not scraped off enough of the black coating off the resistor, or is it an issue with the code?

[lfreed]

Hi Fisu,

When you scrape the resistor, you have to scrape it to the point of the circuit flowing open, with no resistance. I think that's the primary issue. I don't see anything wrong with the code at a glance, but if you still want to check, there is a reference manual and an example program in this GitHub repository for the TinyCircuits Dual Motor library.

https://github.com/TinyCircuits/TinyCircuits-TinyShield_Motor_Library

Let me know if that works!

- Lilith

[Fisu]

Thank you. I kept scraping but the resistance reading kept increasing. Eventually I scraped it so hard that the resistor broke off. So I got the desired result in the end. Thanks.