2 channel Relay driver project can be controlled by feeding 2-12V trigger voltage, Very useful project for application like Micro-Controller based projects, Remote controller, Lamp on Off, and any circuits which required isolated high current and high voltage switching by applying any TTL or CMOS level voltage. Two LED works as operation indicator while in , 3 pins screw terminals to connect load and provides both normally open and normally closed switching.
Input: 12 VDC @ 84 mA
Output: Two SPDT relay
Relay specification: 5 A @ 230 VAC
Trigger level : 2 to 12 VDC
Header connector for connecting power and trigger voltage
LED on each channel indicates relay status
Power Battery Terminal (PBT) for easy relay output connection
Four mounting holes of 3.2 mm each
PCB dimensions 49 mm x 68 mm
2 Channel Relay Board - [Link]
8 Channel Relay Board is a simple and convenient way to interface 8 relays for switching application in your project. Input voltage level support TTL as well as CMOS. Easy interface with Microcontrollers based projects and analog circuits.
8 Channel Relay Board - [Link]
Add a video monitor to your arduino via serial !! You can use it as your prefered output or as a secondary screen for the results of your sketch.
All you send through the serial will be printed out on your TV screen. (You can use an old TV).
On Arduino, you must connect TX from arduino to RX (blue borne) of this my rig adapter. Or on a PC, you can connect direct via USB cable.
Add a video monitor to your Arduino using USB Serial TTL to RCA TV input - [Link]
Hemal Chevli wrote an article detailing his new tool the GLCDTerm that reads serial data without PC on GLCD:
I’m calling it GLCDTerm(spin-off from GTKTerm), this handy tool reads TTL serial data and displays it on GLCD. This is the first time I’ve used a GLCD in any of my projects. It runs on m328 using arduino bootloaer and the awesome GLCD library. I first made a prototype on one of my arduino clones, Below is the video running diagnostics program.
Read serial data without PC on GLCD – [Link]
bogdan informed us about his latest post on electrobob.com. It’s about a level translator for WS2812 LEDs. He writes:
WS2812 LEDs are one of my favourite toys. Apart from all the things that you can do with them in terms of lighting, displays or even light painting you can also use them for your projects as indicator lights.
The great advantage comes from the fact that you can use a single pin to drive so many of them and it takes just 3 wires ran across the whole box for practically any number. This in turn comes with the disadvantage of more complex control and problems driving them (5V devices) from a 3.3V microcontroller.
WS2812 level translator - [Link]
Ralph shared his auto-reset feature of his Arduino board. He writes:
Various versions of the Arduino will reset the board by toggling the serial DTR line, a feature called auto-reset. Since it relies on the DTR line, it won’t work with TTL serial adapters that don’t break out the DTR line. After writing my half-duplex serial UART, I thought of using the TTL serial break signal which holds the line at 0V for several ms. Normal serial communications would also send 0V, but at 57.6kbps, it would never last more than 160us before returning to the idle high voltage state. So what I needed was a circuit would not reset when the line is low for 160us, but would reset when the line is low for 100ms or more.
Zero-wire serial auto-reset for Arduino - [Link]
asidorenk @ obddiag.net pointed us to this great little USB to Serial board:
This USB to serial (TTL) converter project is easy to build, it is simple and inexpensive. It is based on the PL2303SA USB to USART bridge from Prolific. The PL2303SA chip is not required an external crystal as the internal clock oscillator is continuously tuning up to USB bus frequency. Having chip in SO-8 packaging does not require special soldering skills to assemble the project. Please note: the TX and RX signal levels are 3.3 Volts.
USB to Serial Breakout Board for Prolific PL2303SA - [Link]
Chris from pyroelectro says that designing circuits with pure TTL chips is fun, something that i totally agree with. This time, he used an analog tilt sensor to read the tilt of the board, and an 8 by 8 led matrix for display. He used only analog chips to implement this project. Good work!
Pure analog tilt sensor - [Link]
This morning I decided its about time I learn how to use the UART hardware in most PIC microcontrollers. I started off with a USB-RS-232 converter that I got for US$3 from DealExtreme. There are a few reasons why I used a converter, firstly being because my main PC no longer has an RS-232 port since its old tech, but also because I thought it’d be alot neater for my projects to have a USB connection and it means I can interface with TTL signal levels (0-5v) instead of the RS-232 standards -12v – +12v which would have added complications, but we’ll get back to that just now…
Learning Serial Communication - [Link]
The last project I built, the Masochist’s Video Card reminded me of how fun pure TTL digital design can be and since the 7400 contest seems to be allowing multiple entries, I figured why not build something else?
The accelerometer is an interesting sensor that is now extremely tiny thanks to MEMS technology. Specifically, the accelerometer senses gravity, and since earth has a constant 1 g-force always pulling toward the center, we can use that reference to find the tilt of any object. With some digital design and LEDs added to the mix we can even build a tilt sensor as I will show you in this article.
TTL Tilt Sensor - [Link]