Test run of VFD display using Arduino

Among my electronics junk, I found a VFD (Vacuum Fluorescent Display) display and wanted to make sure it still works and can be used in projects. It’s a 16T202DA1E display manufactured by Samsung. It can replace standard HD44780 based liquid crystal display out of the box. First of all, it only requires a 5V supply. The voltage step-up circuit for lighting fluorescent display is already on board. The controller accepts the same commands as any 2×16 LCD does. The pin-out of display is as follows:

Continue reading

Testing LCD keypad Shield for Arduino

arduino lcd keypad shield

Recently I’ve got an Arduino LCD keypad shield. Haven’t decided yet where will it be used. But why not to plug it to Arduino board and see it working. The shield was initially introduced by DFRobot who has some cool open-source stuff including robotics related. This LCD keypad shield is a cheap and convenient solution for adding 2×16 LCD and five push buttons (+1 reset) to Arduino design. LCD here is interfaced using 4-bit mode and occupies 4 (D4), 5 (D5), 6(D6), 7(D7), 8(RS), 9(E) and ten digital pins. Pin 10 is used to control LCD backlight through transistor key. All five buttons are connected to single Analog pin 0 using a resistor-based voltage divider. This lets us keep other pins for general use. The shield is designed to work with 5V based boards.

Continue reading

Understanding and interfacing LDR – light dependent resistors

light dependent resistor

LDR (Light Dependent Resistor) is a simple, cheap electronic device. Simply speaking this is a resistor in which resistance varies depending on light intensity. You’ve probably seen typical LDR in some projects where light intensity has to be taken in to account. They can be used to activate light switches, alarms, adjust display brightness and more. Light-dependent resistors can be different types. They vary in light-sensitive material used. Visible spectrum LDR is made using Cadmium Sulphide (CdS) or Cadmium Selenide (CdSe). This material is sensitive to the wavelength range from 400nm – 850nm. For near infrared spectrum (1μm – 3μm) there are PbS or PbSe materials used. For deeper infrared range (3μm – 1000μm) there are InSb and InAs.

Continue reading

Drive DC motor using Arduino motor shield

arduino motor shield with dc motor

This is a continuation of the previous post where we have tried to run a servo using arduino motor shield. This was a simple task to do with the Arduino Servo library. Today we are going to push things a bit forward and drive DC motor using the same motor shield. This motor shield is capable of running small DC motors that require less than 0.6A of current and operating voltage is less than 25V. In my drawer, I found a small 12V motor which will fit for this demo. Before we begin programming, we need to connect the motor to the Board. We are going to use M1 connector.: Since the motor requires a 12V power supply, we are going to use an external power supply. It can be connected to the External power screw terminal. Be sure to remove the jumper as well.

Continue reading

Testing Arduino motor shield with servo motor

Arduino motor shield

Recently I’ve got an Arduino motor shield. It is based on ladyada first mshield circuit. It uses two famous L293D quadruple half-H divers. It is a cheap and reliable shield to drive various motors. These can be two hobby servo motors, four bidirectional DC motors or 2 (unipolar or bipolar) stepper motors. The load current is limited to L293D chips. The specification says that each channel can provide constant 0.6A and peak 1.2A. There is also a thermal shutdown to prevent the circuit from damaging. Motors can be externally powered using voltage range from 4.5V to 36V. Each motor control channel is pulled down with a resistor to disable any motor at power up. In this post we are going to try servo motor control There are couple connectors on motor shield where you can connect two servo motors using standard 3 wire connector (GND, VCC and PWM).

Continue reading

Alamode – an Arduino that sits on top of Raspberry Pi

Raspbery Pi isn’t that convenient when speaking of controlling thins using GPIO. First of all Hardware. Raspberry Pi pin control might be a bit scary for new players, while Arduino is rich in libraries and information. Alamode designed by wyolum team is somewhat compromise that binds Arduino and RasPi. This is practically an Arduino board that connects to Raspberry Pi GPIO header. Alamode has everything it needs to run as stand alone Arduino as well, but this wouldn’t be a fun and there are other Arudinos that already does that. How can you benefit by putting Alamode on RasPi? Simply speaking you can run a simple Api on Arduino that responds to commands coming from Raspberry Pi. This way you get convenient I/O module with internet integration. RaspPI can be programmed using any language (It’s a Linux). Even Arduino can be programmed directly from Pi. Alamode has more than I/O pins. Atmega on board automatically adds Analog ability to RaspPi. There is a Fastrax UP501 GPS connector broken out if you want to add this functionality. Another feature that Pi lacks is RTC. Alamode has a DS3234 Real Time Clock with battery backup. So it can send time stamps to…

Continue reading

Adding DAC to Arduino or any other microcontroller

Most of the 8-bit microcontrollers lack integrated DAC (Digital to Analog Converter) functionality. This is handy when you need to generate analog signals out of digital information. Adding DAC to any existing microcontroller is a piece of cake. But before you start why not to look at various options available. Embedded newbie provides a review of Arduino DAC solutions. Beginning with the R-2R ladder solution list goes through multiple ways of converting digital to analog. Depending on your needs and speed required there can be a PWM DAC converter that is nothing more than digital signal passed through low pass filter. This is how motor control works. Its relatively slow, but serial that gives an advantage when small pin count microcontrollers are used. In the other hand is signal speed is an issue then parallel DAC – same R-2R ladder probably with an output buffer circuit. And lastly, there is always an option to use specialized DAC chips that can be interfaced through one of the available interfaces like SPI. These save space and MCU pin and still provide high resolution and speed.

Continue reading