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Phototrigger
Phototrigger

Features

  • periodically shots a photo allowing time lapse photography (can be combined with bulb mode), max time between photos: 99:59:59 (h:m:s),
  • bulb time (maximum 99 h 59 m 59 s),
  • postponed start (up to 24 h in advance),
  • powered by 2 AA(A) batteries (3V),
  • 2 × 16 characters LCD display + encoder for easy control,
  • easy to use software,
  • minimal number of components, small PCB,
  • RTC clock (no calendar),
  • low battery indicator.

Design

Device uses ATMEL's atmega168 micro controller (at the time of writing this ar

Aquaticus AVR JTAG

This article provides information about JTAG interface and describes how to create simple working device. This interface is original design of Aquaticus ROV team. Since 2006 it became quite popular among hobbyists thanks to its simplicity and usability. Version B is described here.

The interface is compatible with every software that supports JTAG ICE, it works perfectly with AVR Studio and Linux tools.

Aquaticus PWM guide

Introduction

This guide describes principles of PWM for Atmel AVR micro controllers. It is not complete documentation for PWM nor AVR timers but tries to lighten some practical aspects of PWM. Some of the PWM aspects are simplified, some are not mentioned at all. Usability was the main factor when writing this text. Full PWM description can be found in Atmel AVR documentation.

Although the article was written based on ATmega16 and ATmega32 documentation, information is useful for any chip from AVR family.

BLDC controller
BLDC controller

After examining BLDC controllers available on the net (mostly for RC airplanes), I decided to design and build my own controller for robots.

Requirements

  • Sensorless
  • Max voltage: 12V
  • Max current: 10A
  • I²C for control
  • RS232 (5V) for diagnostic and configuration
  • No SMD parts
  • Minimum additional elements
  • ISP connector for programming

Controller is based on Atmel ATmega8 chip with limited number of external components. Preliminary design is finished.

Control unit
Control unit

Device was designed to be used as control unit for ROV or any other remotely controlled robot. As primary communication interface is used RS485. It allows controlling robot using 1200m long cable.
Several other interfaces allows reading data like temperature, depth and heading.

Normally ROV receives commands from the surface and sends back data read from sensors. Special software has to be written to perform this task.


Main features

  • Atmel Atmega16 or Atmega32 microcontroller
  • 1×RS485 for communication with surface
  • 2×RS232 to control devices with serial interface, for example Roboteq motor controllers.
  • 5×I²C header to connect any I²C device like CMPS03 digital compass, temperature sensors or BLDC controllers.
  • 3×multi purpose header to be used as:
    • ADC input for sensors with voltage output, or
    • ADC input for sensors with current output like pressure sensor, or
    • digital input, or
    • digital output, or
    • servo controller
  • 1-Wire bus
  • LANC or IR interface to control camera
  • 2×leak sensor
  • ISP header to program microcontroller
  • 15 pin header to connect Motor Controller
  • Power voltage sensor
  • JTAG support

ROV sensor board
ROV sensor board

One of the best methods to visualize ROV data is to show them as overlay on images from camera.
This project can be used in any ROV. It presents data read from sensors mixed with video signal from camera. It can read data from analog 4-20mA sensors and from I²C chips. Although project assume usage of specific sensors, any I²C or 4-20mA sensors can be used. Only software needs small modifications.
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