This page has details on running a USFIRST FRC jaguar from an Arduino The Adaptor Board is available at: http://www.sparkfun.com/products/9281 First step involved speed control via the serial link. // #include <avr/interrupt.h> const int jagsigpin = 9; //pwm connection on pin 9 const int jagpwrpin = 7;//using pin 7 as the pwm power reference const int jaggndpin = 8;//using pin 8 as the pwm ground reference const int ledpin = 13;//using the standard LED as a status indicator const int buffsize = 3;//determining the digits buffer size char mybuffer[buffsize]; //declare an array to take input from the serial int value = 47;// decimal 47 corresponds with the pwm midpoint int minvalue = 20;// decimal 20 corresponds with the pwm full reverse int maxvalue = 74; //decimal 74 corresponds with the pwm full forward boolean ledstatus = LOW; //initialize the LED status void setup() { //set the PWM frequency to be 122Hz TCCR1B = TCCR1B & 0b11111000 | 0x04; //setup the pins to be used with the PWM pinMode(jagsigpin, OUTPUT); pinMode(jagpwrpin, OUTPUT); pinMode(jaggndpin, OUTPUT); //setup the LED status pin pinMode(ledpin, OUTPUT); //define the pwm reference voltages digitalWrite(jagpwrpin,HIGH); digitalWrite(jaggndpin,LOW); //start the serial interface... 9600 is arbitrary Serial.begin(9600); //set the pwm to midscale so the jaguar starts in a friendly state analogWrite(jagsigpin,value); } void loop(){ //wait for there to be something on the serial interface if(Serial.available()>0){ // give time for the rest of the digits to come across delay(100); // 8bit characters (chars) come across the serial interface, each one is an ascii value // group these characters into a char array for processing for(int i =0; i<buffsize; i=i+1){ mybuffer[i] = Serial.read(); } Serial.flush(); //use the c function "atoi" to convert the char array to a integer value value = atoi(mybuffer); // print the value to the console Serial.print(value); //write the pwm value analogWrite(jagsigpin,value); //toggle the indicator ledstatus = ~ledstatus; digitalWrite(ledpin,ledstatus); Serial.write('\n'); } } References: Changing the Arduino PWM frequency Page 5, Table 4 has the PWM timing information Autoramp mode was necessary to not trip the overcurrent protection on my bench power supplies Check out Q7 for Details on enabling:  |