Custom Packet Sniffer Is A Great Way To Learn CAN

Whilst swapping out the stereo in his car for a more modern Android based solution, [Aaron] noticed that it only utilised a single CAN differential pair to communicate with the car as opposed to a whole bundle of wires employing analogue signalling. This is no surprise, as modern cars invariably use the CAN bus to establish communication between various peripherals and sensors.

In a series of videos, [Aaron] details how he used this opportunity to explore some of the nitty-gritty of CAN communication. In Part 1 he designs a cheap, custom CAN bus sniffer using an Arduino, a MCP2515 CAN controller and a CAN bus driver IC, demonstrating how this relatively simple hardware arrangement could be used along with open source software to decode some real CAN bus traffic. Part 2 of his series revolves around duping his Android stereo into various operational modes by sending the correct CAN packets.

These videos are a great way to learn some of the basic considerations associated with the various abstraction layers typically attributed to CAN. Once you’ve covered these, you can do some pretty interesting stuff, such as these dubious devices pulling a man-in-the-middle attack on your odometer! In the meantime, we would love to see a Part 3 on CAN hardware message filtering and masks [Aaron]!


easyavr.h Header file for pin/port operations

Here I am sharing a header file called easyavr.h. This is a pretty basic header file with some helper functions related to input output pins of AVR

#ifndef __EASYAVR_H_
#define __EASYAVR_H_

//  Sets pin of port to 1
//  Example for PD2: PIN_ON(PORTD, 2)
#define PIN_ON(port,pin) ((port) |= (1 << (pin)))

//  Sets pin of port to 0
//  Example for PD2: PIN_OFF(PORTD, 2)
#define PIN_OFF(port,pin) ((port) &= ~(1 << (pin)))

//  Sets pin of port to value
//  Example for PD2: PIN_SET(PORTD, 2, 1)
#define PIN_SET(port,pin,val) (((val) > 0) ? PIN_ON((port),(pin)) : PIN_OFF((port),(pin)))

//  Sets all of port pins to OUTPUT mode
#define PORT_AS_OUTPUT(port) ((port) = 0xFF)

//  Sets all of port pins to INPUT mode
#define PORT_AS_INPUT(port) ((port) = 0x00)

//  Sets pin of port to OUTPUT mode
//  Example for PD1: PORT_AS_OUTPUT(DDRD, 1)
#define PIN_AS_OUTPUT(ddr,pin) ((ddr) |= (1 << (pin)))

//  Sets pin of port to INPUT mode
//  Example for PD1: PORT_AS_INPUT(DDRD, 1)
#define PIN_AS_INPUT(ddr,pin) ((ddr) &= ~(1 << (pin)))

//  Checks pin's value of port
//  Returns 1 or 0
//  Example for PD2: CHECK_PIN(PIND, 2)
#define CHECK_PIN(pinreg,pin) (((pinreg) & (1 << (pin))) != 0)


Chocometer :an open source near infrared sensor aiming glucose measurements without pain.

marcelclaro’s project for The Hackaday Prize aims to do just that. Instead of measuring blood directly, his project will measure blood glucose by shining light through a finger or an earlobe. Using light to detect blood glucose is something that has been studied in the lab, but so far, there aren’t any products on the market that use this technique.

There are two major problems marcel needs to overcome to turn this project into reality. The first is simply raw data for calibration. For [marcel], this is easy; he has Type 1 diabetes, and takes four glucose measurements a day. Patient heal thyself, or something.

The second problem is getting a photosensor that’s sensitive enough. By using an InGaAs PIN diode, a current-controlled oscillator, and a digital counter, [marcel] should have a sensor that’s good enough, with electronics that are cheap enough, to create some tech that is truly game changing for a few hundred million people around the world.


Simulating Arduino in Proteus VSM

 This is an old post which I am reposting… also check Simulating Arduino Mega2560 in Proteus.

Arduino platform is a great tool for everyone who wants to play with microcontrollers in a simple and inexpensive way. It offers perhaps the quickest and easiest ways to do cool stuffs with its rich built-in library and easy to grasp interface. It’s also open-source and for this reason there are many open-source projects with it in the Internet. I have personally enjoyed it a lot. Although Arduino is pretty popular amongst many users, there is no good simulator software for it. Proteus VSM, on the other hand, is a very good circuit simulator software. However it lacks a model or simulator primitive for Arduino. Thus simulating Arduino in Proteus is in a way impossible. If these powerful tools can be synced together then a lot of new possibilities will arise. This is what I wondered from day one of Arduinoing. In this doc we will discuss how to integrate these software and simulate Arduino in Proteus.In Proteus we need to add a .hex or .coff file in a micro in order to simulate its behaviour. However Arduino works with .ino or .pde files and the folders that hold Arduino sketches don’t contain .hex or .coff files. Thus there’s no straight way. Now if there’s no straight path then we have to go around.Firstly we have to make a suitable Proteus schematic like the one shown. You can also download a template provided at the end of post.

405495_1826120830872_733664937_nOnce the schematic is completed, we have to set the fuses and clock frequency as shown




Analog pH Meter with PIC16F684 and arduino

Need to measure water quality and other parameters?  DF Robot’s Analog pH Meter Kit is  specially designed for simple interface and has convenient and practical connector and a bunch of features. Get pH measurements at ± 0.1pH (25 ℃). For most hobbyist this great accuracy range and it’s low cost makes this a great tool for biorobotics and other projects! It has an LED which works as the Power Indicator, a BNC connector and PH2.0 sensor interface. To use it, just connect the pH sensor with BND connector, and plug the PH2.0 interface into the analog input port of any micro-controller.

The Wiki page  has a sample code for using this kit with arduino,  along with schematic, specifications, features ,precautions and setup Instructions. The arduino Interfacing is simple and the schematic and code is available on the wiki page.


Interfacing with a pic is also straight forward, Shawon Shahryiar shared his project where he used a PIC16F684. Below is the demonstration video and code.

Coder: Shawon Shahryiar

#include <16F684.h>

#device *= 16
#device ADC = 10


#use delay (internal = 4MHz)

#include "lcd.c"

#define const_A 0.00171016
#define LED	pin_C3

const unsigned char symbol[16] ={
    0x00, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x00, 0x00,
    0x00, 0x00, 0x0E, 0x0E, 0x0E, 0x00, 0x00, 0x00

void setup();
void lcd_symbol();
unsigned long adc_avg();
void show_bar(unsigned char value);

void main() {
    unsigned char samples_A = 0x00;
    unsigned char samples_B = 0x00;
    unsigned long temp = 0x0000;
    unsigned long avg = 0x0000;
    unsigned long buffer[10];
    float pH_value = 0.0;

    memset(buffer, 0x00, sizeof (buffer));


    while (TRUE) {
        for (samples_A = 0; samples_A < 10; samples_A++) {
            buffer[samples_A] = adc_avg();

        for (samples_A = 0; samples_A < 9; samples_A++) {
            for (samples_B = (1 + samples_A); samples_B < 10; samples_B++) {
                if (buffer[samples_A] > buffer[samples_B]) {
                    temp = buffer[samples_A];
                    buffer[samples_A] = buffer[samples_B];
                    buffer[samples_B] = temp;

        avg = 0;

        for (samples_A = 3; samples_A < = 6; samples_A++) {
            avg += buffer[samples_A];

        avg >>= 2;

        pH_value = (avg * const_A);

        lcd_gotoxy(1, 1);
        printf(lcd_putc, "pH Value: %2.2g ", pH_value);
        show_bar(((unsigned char) pH_value));

void setup() {
    setup_timer_2(T2_disabled, 255, 1);

void lcd_symbol() {
    unsigned char s = 0;

    lcd_send_byte(0, 0x40);

    for (s = 0x00; s < = 0x0F; s++) {
        lcd_send_byte(1, symbol[s]);

    lcd_send_byte(0, 0x80);

unsigned long adc_avg() {
    unsigned char samples = 4;
    unsigned long avg = 0;

    while (samples > 0) {
        while (!adc_done());
        avg += read_adc(adc_read_only);
    avg /= 4.0;

    return avg;

void show_bar(unsigned char value) {
    unsigned char x_pos = 0;

    for (x_pos = 1; x_pos < = 16; x_pos++) {
        lcd_gotoxy(x_pos, 2);

    lcd_gotoxy((value + 1), 2);


Solar Charge Controller Improves Efficiency of Solar Panels

The simplest and easiest way to charge a battery with a solar panel is to connect the panel directly to the battery. Assuming the panel has a diode to prevent energy from flowing through it from the battery when there’s no sunlight. This is fairly common but not very efficient. [Debasish Dutta] has built a charge controller that addresses the inefficiencies of such a system though, and was able to implement maximum power point tracking using an Arduino.

Maximum power point tracking (MPPT) is a method that uses PWM and a special DC-DC converter to match the impedance of the solar panel to the battery. This means that more energy can be harvested from the panel than would otherwise be available. The circuit is placed in between the panel and the battery and regulates the output voltage of the panel so it matches the voltage on the battery more closely. [Debasish] reports that an efficiency gain of 30-40% can be made with this particular design.

This device has a few bells and whistles as well, including the ability to log data over WiFi, an LCD display to report the status of the panel, battery, and controller, and can charge USB devices. This would be a great addition to any solar installation, especially if you’ve built one into your truck.

via Hackaday


Measuring Heart Rate With A Piezo

Look around for heart rate sensors that interface easily to microcontrollers, and you’ll come up with a few projects that use LEDs and other microcontrollers to do the dirty work of filtering out pulses in a wash of light.

[Thomas] was working on a project that detects if water is flowing through a pipe with a few piezoelectric sensors. Out of curiosity, he taped the sensor to his finger, and to everyone’s surprise, the values his microcontroller were spitting out were an extremely noise-free version of his heart rate.

The piezo in question is a standard, off the shelf module, and adding this to a microcontroller is as easy as putting the piezo on an analog pin. From there, it’s just averaging measurements and extracting a heartbeat from the data.



AVRWIZ automatic code generator for AVR microcontrollers

AVRWIZ is a code generator for the popular Atmel AVR microcontrollers, optimized for the AVR Studio IDE. Its a very nice automatic code generator for AVR microcontrollers developed by tcg in avrfreaks, which can generate code for most common tasks. It  support baud calculator, timer calculator, multitasking generator, interrupts, ports and more. But there are several thing to be done like TWI, USI. As Author states there is lots of testing to be done. Project is open for new ideas and suggestions.

Nice thing I like about it that program is capable to generate code instantly. It can be saved as single file or whole Avr Studio project with makefile which is ready to compile instantly.

I Like the older version although it has less features still its clean and fast, get it and give it a try. The latest online version has moved from and now can be found here.

AvrWiz V 22 (latest) 











Pic based temperature sensor with 7 segment display and ds18b20

This circuit is a Digital Temerature Sensor using a Dallas ‘1-wire’ DS18B20 Digital Thermometer

Firstly I would like to thank Pommie and Mike, K8LH from the Electro Tech Online Forum for their genourous help. This has been the most challenging project to date and they have helped immensely. They have tought me many valuable lessons about programming in Assembly language and it has really assitsted me in getting this project up and running.

Note: I would like to make a point that some snippets of their own code is used in this program. I have used it with their permission and please observe any copyrights or name recognition placed in the code. If you wish to use their snippets of code, please contact them via the Electro-Tech-Online forum.

How It Works

The DS18B20 is a direct-to-digital temperature sensor using Maxim’s exclusive 1-Wire bus protocol that implements bus communication using one control signal. In regards to hardware, this particular sensor is particularly easy to interface to. It only requires 1 external pull-up resistor to operate as opposed to an analogue sensor which possibly needs multiple external components such as resistors and op-amps.

In regards to software, opposed to analogue sensors, the Dallas 1-wire digital sensors are arguably as easy to interface to. While an analogue sensor will need an Analogue to Digital conversion using a voltage reference and possibly using an op-amp, the Dallas 1-wire direct to digital sensors require precise timing when it comes to communication. This program is fairly basic in principle as all it does is obtain temperature data from the DS18B20 sensor and display the temperature in Degrees Celsius on a 4 digit, 7 segment display. But when it comes to actually doing this, as you will see from the .ASM file, it is more complicated than it sounds. In words; the program first initialises the PIC16F628A Microcontroller. It assigns the Inputs and Outputs, zero’s all bank 0 RAM, initialises the display column select bit and configures TIMER 2. TIMER 2 is used to interrupt the normal loop of the program to update the 7 segment LED display.

After the Microcontroller has been setup, it begins communication with the DS18B20 Temperature Sensor. Communication routines take up just under half of the program memory. After the temperature has been gathered and stored in RAM, the Microcontroller takes the 12-bit signed/fraction integer and converts it into a decimal number then stores it in four general purpose registers in RAM.

For example, take the number D’95.8′. It is stored like this:

HUNS register = 0
TENS register = 9
ONES register = 5
TENTHS register = 8

These registers are then used within the Interrupt Service Routine to call a table to obtain display data.
The program runs continuously, updating the temperature on the display just over once per 1 second.

Features Summary:

  • Temperature data gathered more than once per second.
  • TIMER 2 interrupt driven display.
  • Program expandable to include multiple sensors on the same 1-Wire bus.
  • Temperature range of -55.0 – 127.9 Degrees Celsius.

Please see the DS18B20 Datasheet for detailed information on the device.


Here is the complete project   (with explanation , code, schematic and video)