R-B | Embedded Lab

Author Archives: R-B

Arduino capacitance meter

Posted on November 2, 2015 by R-B One comment

Electro-Labs’ DIY capacitance meter can measure capacitors rated from picofarads to millifarads. The circuit is based on Atmega328P and is Arduino IDE compatible. The capacitance is computed by measuring the capacitor charging time and is displayed on a Nokia 5110 LCD.

DIY capacitance meter

The main component of the circuit is Atmega328P microcontroller (MCU) and it runs at 16MHz. RESET, MOSI, MISO, SCK, RX, TX, 5V and GND pins are extended to the connectors from J4 to J11 to let the user use an Arduino or an AVR programmer to program the microcontroller in ICSP mode. MCU reset button, a general purpose button and a general purpose LED are also connected to the MCU. You can check out this tutorial to see how to burn a Arduino bootloader to a new microcontroller and then program it using the Arduino IDE.

There are two linear voltage regulators on the board. L78L05 and L78L05 generate 5V and 3.3V from 9V input. The MCU needs 5V and the LCD needs 3.3V to operate. The current consumption of the board is low, so no cooling is required.

Making a simple follow-me robot

Posted on October 10, 2015 by R-B 2 comments

Saurav Chakraborty has shared his making of a very basic DIY follow-me robot that uses no microcontroller. It uses two sets of IR photodiodes and an IR LED to sense the presence of an object in fron of it. When the object is sensed, two DC motors are turned on using transistor switches and the robot moves forward. The robot can also follow left and right path based on the motion of the front object.

DIY follow-me robot

Energy meter using Atmel 90E24

Posted on September 24, 2015 by R-B 3 comments

Atmel’s 90E24 is a high-performance active and reactive energy metering device for single-phase two-wire, single-phase three-wire or anti-tampering active and reactive energy meters. Here is a demo power line monitor project using Atmel 90E24 and allows voltage, current, true power, apparent power, reactive power, power factor, phase angle, and line frequency to be accurately measured.

AC power line monitor using Atmel 90E24

Arduino controlled low-cost robotic arm

Posted on September 24, 2015 by R-B One comment

Induatrial robotic arms are quite expensive. Dan Royer is building an Arduino-controlled open-source robotic arm affordable to the DIY makers community.

Open-source 5-axis robotic arm

Industrial arms starts at $10k each and go up from there. With low cost hardware everywhere now, I see a market opportunity for low cost arms to serve small industry. I’d like to drive the cost down by making an arm that others can tinker with, improve on, and build community around. I’d like to see two arms assemble a third.

Tell Elon Musk I need his rockets – lets put Marginally Clever robots to work building that lunar colony.

PIC24-based game console

Posted on September 23, 2015 by R-B One comment

Voja antonic‘s single chip game console is based on PIC24EP512GP202 microcontroller, a 16-bit Microchip’s MCU which is programmed to generate the VGA signal, music and sound effects for playing Jumping Jack.

Single chip game console

As the video signal and the corresponding sync signals are generated by software, the console contains a minimum of hardware. There is also an audio signal output with five binary tone channels, mixed by a passive resistor network. Two of those channels are used for sound effects, similar to ones used in video games of that time (early eighties) and three for background music. This output is capable of driving line output for PC speakers or headphones.

It should be noted that there is no video processing unit, PGA or any special purpose chips, and that PIC microcontrollers are not designed for video signal generation. Everything is achieved by a series of different design tricks and some compromises. As te game does not run on PC but on stand-alone unit, screenshots are taken by camera from VGA monitor or directly from Photoshop, which was used in bitmaps creation process.

Video and audio generators, which are the vital parts of the firmware, are the parts of the operating system, which will soon be documented, and can be used for any other game or application. As the timings are critical, those parts are written in assembly language, but all the other parts of the program (scenario for some other games or any other application) may also be written in some other programming language, preferably Microchip’s C. In this case all parts are written in Assembler, but only as a result of author’s preference.

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