I know it's an old thread but since the 2013 FRC is up and running...

I tried and failed, but I read after!

The problem is the PWM on the jaguar runs at 15 kHz, the PWM on Arduino is 500Hz. Which is way slower.

To communicate with the jaguar you will need to modify some register on the Arduino to make the PWM go faster.

I haven't tried it, but I think this link is a good start : http://playground.arduino.cc/Code/PwmFrequency

Hi there,

I also started to build an aquarium controller for my reef. I currently have a problem with the float switches.

Digital problem :
When I read from the digital pins, it returns the good value half of the time when the switch is on.

Analog problem :
When reading from the analog pins, I use a threshold (value of 100) to check if the float switch is on. Everything works using a single float switch, but using multiple the values decrease and mostly pass under my threshold.

What cause these problems?

Hmmm... I have check all my bricks from them and I don't see the + - s markings. They might have add them lately.

I know it's been a while, but I didn't touch my arduino for a while.

I figured out that arduino-direct don't always follow wire color standards. After checking the PCB, I noticed that they flipped their cables color. The black wire is for signal and the white as the ground...

Now it works, I only need to converted the value to human readable.

Thanks

I know it's been way long time ago, but I just restarted to look to my "what I thought" defective clock.

I just read that the SDA and SCL are respectively on pin 20 and 21 for the Arduino Mega...

Source : http://www.arduino.cc/en/Reference/Wire

How did I found out, I just bought a Duemilanove and the clock worked perfectly.

Should have RTFM!

I've found the code from a Chinese web site, but it still gives only 9 as a value.

http://translate.google.ca/translate?js=n&prev=_t&hl=fr&ie=UTF-8&layout=2&eotf=1&sl=auto&tl=en&u=http%3A%2F%2Fitem.taobao.com%2Fitem.htm%3Fid%3D6208909767&act=url

Code:

#include <math.h>

double Thermister (int RawADC) {
 double Temp;
 Temp = log (((10240000/RawADC) - 10000));
 Temp = 1 / (0.001129148 + (0.000234125 * Temp) + (0.0000000876741 * Temp * Temp * Temp));
 Temp = Temp - 273.15; // Convert Kelvin to Celcius
 Temp = (Temp * 9.0) / 5.0 + 32.0; // Convert Celcius to Fahrenheit
 return Temp;
}

void setup () {
 Serial.begin (115200);
}

void loop () {
 Serial.println (int (Thermister (analogRead (A0)))); // display Fahrenheit
 delay (100);
}

Wasn't aware there was a way to post questions.

Where : http://arduino-direct.com/sunshop/index.php?l=product_detail&p=39
What : Thermistor 103 with a LM358 chip and some resistors.

Code :

Code:

int thermPin = A0;
float thermValue = 0;

void setup ()
{
  Serial.begin (9600);
}

void loop ()
{
  thermValue = analogRead (thermPin);
  Serial.println (thermValue);
  delay (1000);
}

Hello,

I'm a software developer, but I'm also a total newbie in electronic. I've bought the thermistor shield from arduino-direct. When I try to read the value, I always get 142 ±1. Nothing happens even when I try to heat the thermistor with my fingers.

Is there any tutorial using this shield?

Thank you

Ok. I don't have the shield in my possession right now. I lend it to a friend who will check the potential issue with it.

Thanks Eric, I'll give it a try later.

EP

This is the RTC shield that I bought.

http://cgi.ebay.ca/DS1307-Based-Real-Time-Clock-Arduino-I2C-/230584918558?pt=LH_DefaultDomain_0&hash=item35afeea21e#ht_753wt_1139

I'm not sure these ebay store from China even care for their customers... I will send him the link to this thread.

Ok, I realized that the relay 1 and 3 were defective  . Well, there is no clicking sound from them. I'll test them later directly with their pins. After all, I'm not that dumb.

Hi there,

I'm a total newbie in electronics, but I want to learn. I'm a software developer.

I bought the follow relay module http://cgi.ebay.ca/5V-4-Channel-Relay-Shield-Arduino-Electronic-DIY-/110648585724?pt=LH_DefaultDomain_0&hash=item19c32b6dfc#ht_1351wt_1139.

I thought that I knew how the basics of relay worked, i.e. put a small voltage and it close/open a switch. But nothing seems to work.

I have connected the VCC and the ground to the board and connected K1 to pin 13. Now let say for testing purpose I want to make a led blink from the relay, where do I plug the cables?

Thanks

It's a small rtc shield that i got from eBay. There are two ways to connect it using A4-A5 directly or with some sda and sdc connection.