I'm using Keil to program the AT89C52 Microcontroller. I define a sbit to be a single pin of a port.
For eg: sbit a = P0 ^ 0;
But when I set a = 1, then I get the pin in a gray color in proteus where I run the program on simulated hardware. For high, the pin should be red. I'm trying to interface the LM041L LCD. Please help. I'm very new to this and I don't understand what is casing this
The 8 pins on P0 are in open drain mode by default. When you use these 8 pins as outputs, you should imply a pull up resistor in order to output a high signal.
Related
So I am building a donkey car in raspberry pi 4 2gb. I have installed the software and all libraries needed and made changes in myconfig.py. My car runs properly, but I couldn't calibrate it to turn properly (left and right) according to https://docs.donkeycar.com/guide/calibrate/. If anyone could help it would be great.
code changes in myconfig.py
# #CAMERA
CAMERA_TYPE = "WEBCAM"
IMAGE_W = 200
IMAGE_H = 120
DRIVE_TRAIN_TYPE = "DC_TWO_WHEEL_L298N"
DC_TWO_WHEEL_L298N = {
"LEFT_FWD_PIN": "RPI_GPIO.BOARD.16", # TTL output pin enables left wheel forward
"LEFT_BWD_PIN": "RPI_GPIO.BOARD.18", # TTL output pin enables left wheel reverse
"LEFT_EN_DUTY_PIN": "RPI_GPIO.BOARD.22", # PWM pin generates duty cycle for left motor speed
"RIGHT_FWD_PIN": "RPI_GPIO.BOARD.15", # TTL output pin enables right wheel forward
"RIGHT_BWD_PIN": "RPI_GPIO.BOARD.13", # TTL output pin enables right wheel reverse
"RIGHT_EN_DUTY_PIN": "RPI_GPIO.BOARD.11", # PWM pin generates duty cycle for right wheel speed
}
This question is probably best asked in the robotics stackexchange or the donkeycar discord. But to answer your question, a differential drive robot (you've chosen the DC_TWO_WHEEL_L298N drive train, so I am assuming you have two motors connected to the L298N) does not need to have it's steering calibrated. So you can ignore that calibration step. The robot is steered by varying the throttle to each motor. For a left turn, the left motor is given less throttle, so it's wheel will turn slower than the right wheel; that will cause the robot to turn in a leftward arc. A right turn is similar but the right wheel turns slower.
I'm trying to control my 180 degree servo motors through a Adafruit 1411 Servo shield. However I don't find it simple enough to write the servo's position in angles like the normal servo library without the shield.
Using the Adafruit 1411 Servo shield and Adafruit_PWMServoDriver-library lets you control a servomotor by modifying its pulselength as far as I've realised. To my question..
Is there a way for me to either use the servo shield's output and still write in degrees OR somehow convert these pulselength into angle-degree?
Example of the differences:
Adafruit_PWMServoDriver-library:
pwm.setPWM(Servo, 0, pulseLength);
Servo-library:
Servo.write(45); //Writing in angles like this would be optimal for my project.
Any help in the right direction is much appreciated!
Use the Arduino map function. The following is from the Adafruit instructions:
pulselength = map(degrees, 0, 180, SERVOMIN, SERVOMAX);
Where SERVOMIN and SERVOMAX are values you set according to the range of travel of your servo. This linearly maps a value between 0 and 180 into the range between SERVOMIN and SERVOMAX.
Since you've been doing this with pulse widths so far, you probably already knew the values you need to use.
I have been struggling with arduino and ultrasonic sensor HC-SR04 and PWM.
I am using arduino pro mini. Also using NewPing library.
the newping library example works perfectly if I have just the sonar attached and I get about 170cm when pointing upwards towards the ceiling.
However if I add a pwm call on a different pin(pin 3 in this case) the sonar outputs maximum of 41cm, everything below that works, albeit bit noisily.
I have almost nothing connected to the pwm pin, there is only a capasitor and a resistor. I had a motor as well but removed it for debugging.
Illustration of my wiring:
code:
#include <NewPing.h>
#define TRIGGER_PIN 8 // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_PIN 7 // Arduino pin tied to echo pin on the ultrasonic sensor.
#define MAX_DISTANCE 200
NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);
int p = 3;
void setup() {
// put your setup code here, to run once:
pinMode(p,OUTPUT);
Serial.begin(115200);
}
void loop() {
delay(50); // Wait 50ms between pings (about 20 pings/sec). 29ms should be the shortest delay between pings.
Serial.print("Ping: ");
int d = sonar.ping_cm();
Serial.print(d); // Send ping, get distance in cm and print result (0 = outside set distance range)
Serial.println("cm");
analogWrite(p,d);
}
The problem does disappear if I remove everything from the pin 3, but I don't see how this wiring can have any effect, especially with the motor missing.
Any ideas how to get the sonar and pwm working at the same time.
Check the pin color of your HC-SR04. Models with "brass" colored pins have a defect. They might and will return false readings. Models with "silver-y-ish" pins are more precise. The defect isn't there.
Also, try using pins 2 & 3 for the distance sensor and something else for the PWM.
I'm trying to create a robot using three HC-SR04 ultrasonic sensors and my Arduino Pro Mini but I've run into a few problems. In short the robot's function is as follows:
The robot is dual wheeled, with an H-bridge (SN754410) driving each wheel.
There's one HC-SR04 sensor on each side of the robot, the left one activates the left wheel motor when it detects a hand in front of it, vice versa for the right side.
i.e. To make the robot go forward, we place our hands near the left and right side of the robot, to make it turn right, we remove the right hand and keep the left one in place, vice versa for turning left, etc.
A third HC-SR04 is located the top of the robot, such that it activates a third motor when the user's hand is hovering above the robot.
My test code is as follows:
#include <NewPing.h>
#define SONAR_NUM 3 // Number of sensors.
#define MAX_DISTANCE 20 // Maximum distance (in cm) to ping.
NewPing sonar[SONAR_NUM] = { // Sensor object array.
NewPing(4, 5, MAX_DISTANCE), // Each sensor's trigger pin, echo pin, and max distance to ping.
NewPing(6, 7, MAX_DISTANCE),
NewPing(8, 9, MAX_DISTANCE)
};
#define ena1 10 //trigger for left motor H-bridge
//#define ena2 11 //trigger for right motor
//#define ena3 12 //for top motor
long sensors[3]; //array to store sensor distances
void setup() {
Serial.begin (115200);
pinMode(ena1, OUTPUT);
//pinMode(ena2, OUTPUT);
//pinMode(ena3, OUTPUT);
}
void loop() {
for (uint8_t i = 0; i < SONAR_NUM; i++) { // Loop through each sensor and display results.
delay(50); // Wait 50ms between pings (about 20 pings/sec). 29ms should be the shortest delay between pings.
sensors[i] = sonar[i].ping_cm();
}
Serial.println(sensors[0]);
if (sensors[0] > 0 && sensors[0] <= 20){
Serial.println("detected");
digitalWrite(ena1, HIGH);
}else{
Serial.println("NA");
digitalWrite(ena1,LOW);
}
}
As you can see, I'm using the NewPing.h library to collect the sensor data. After each iteration of the for loop, the distances detected by the sensors are stored in a sensor array. When a hand is placed about 15-20 cm away from a sensor, the arduino sends a digital "HIGH" trigger signal to the respective H-bridge, activating the respective motor (I only have one of these pins, "ena1", enabled in my code, the other two are commented for the test).
To test my code, I simply connected the H-bridge trigger pin "ena1" to an LED, this pin is activated by the sensor whose distance data is stored in variable "sensors[0]". However, after I compile and upload my code, I notice that the LED simply flickers faintly as I put my hand in front of the sensor. As if the LED is being turned on and off very fast.
The output from the serial monitor is as follows:
15
detected
0
NA
16
detected
0
NA
14
detected
As you can see, by putting my hand about ~15cm in front of the sensor, the sensor returns the correct distance and the "ena1" pin is set to high (as evidenced by "detected" being printed to the screen).
However, the sensor always returns a "0" value at the next iteration of the main loop (while my hand is still in front of the sensor), subsequently setting the "ena1" pin to LOW again, which might explain why the LED is being turned on and off so fast.
I'm not sure why this is happening... Interestingly, by removing the digitalWrite lines from the code, the sensor returns the correct values (i.e. no "0" value when my hand is in front of the sensor).
Any ideas on how I can fix this?
Thanks in advance!
This might be a hardware error. I've seen cases where, if the pins of the HC-SR04 were a brass (gold-ish) color, the sensor had a tendency to throw out a 0 for distance.
My suggestion is to get an other ultrasonic sensor, preferably with more silver-ish colored pins.
Your code looks good though!
Good luck!
I have a Leonardo generating a square wave using tone(). I ran the output through an LC low pass filter and fed into into a recording jack. Everything works fine for one continuous tone. But if I try and vary the frequency, for example:
loop()
{
tone(8,1300);
delay(10);
tone(8,1500);
delay(10);
}
then every now and again (it varies, e.g. 14ms, 28ms, 71ms) the signal disappears for about 4ms. This happens even when no other code apart from the above is present, i.e. no serial port access etc.
How can I get the Leonardo to generate tones without these gaps appearing?