March 18, 2011

Arduino relays

I'm putting my newly learned Arduino knowledge to practical use. Since I don't really know any electronics, I went to a local electronics supplier called ETT to see what pre-made boards they have. While looking around, I discovered that they make a custom Arduino board with a mouthful name called ET-EASY MEGA1280 Duino Mega that easily connects to their boards using a simple 10-pin connector.


This is the Duino Mega connected to a 5V relay board. The 5V board can be powered directly from the Duino Mega board which is powered from USB. Also connected is a Sharp GP2Y0D21YK infrared sensor. The sensor is a digital sensor with a 24 cm range.


Here's another relay board also produced by ETT. This is a 12V relay board that needs to be externally powered. Actually I got the 12V board first, but then I saw the 5V board that can be powered from the Arduino. But after getting the 5V board I was afraid that it might draw too much power. But both seem to work perfectly fine.

I wrote a little sketch that controls the relays using commands transferred over USB serial as well as reads the status of the infrared sensor. My first Arduino project is a motorized computer scale system. One relay is used to control the motors of the conveyor belt and the second relay is used to toggle a warning siren. The infrared sensor (which will be replaced by a laser sensor in production) is used to sense when to stop the conveyor belt in order to weigh the product.

Of course, the system has a load cell and a weight indicator that also has to be connected to work. The load cell is connected to the indicator through a special load cell connector, and the indicator is connected to the computer using a simple USB serial port converter.

8 comments:

Elton said...

Hi, I just bought two Sharp ir sensors, the analog one, GP2Y0A21YK and the digital one, GP2Y0D21YK. I am having some trouble making the digital sensor work with arduino (not sure if the sensor is good or not). I see you have GP2Y0D21YK working. I wonder if you can tell me how you connect it to the arduino board.

From your picture, you didn't put a 12kohm resister between the +V and Voutput as suggested by the page 2 of the datasheet, http://media.digikey.com/pdf/Data%20Sheets/Sharp%20PDFs/GP2Y0D21YK.pdf Will that work too?

Elton

FRiC said...

Hi, as you can probably see from the photo, I didn't do anything special in connecting the IR sensor to the Arduino board. But the internal pull-up resistor has to be enabled. In my older code, I have:

digitalWrite(SENSOR_PIN, HIGH);
pinMode(SENSOR_PIN, INPUT);

With Arduino 1.0, you would do:
pinMode(SENSOR_PIN, INPUT_PULLUP);

Elton said...

Thank you for your reply. Did you see the IR led light up through a digital camera? I can see the IR light from the GP2Y0A21YK but not from the GP2Y0D21YK. I suspect the GP2Y0D21YK are second hand and malfunction.

FRiC said...

Hi, I think your IE sensor is indeed defective. I can see infrared light using a digital camera.

Elton said...

thanks.

Parneetha S said...

This is a really good blog. I am surprised that the new technology. thanks for your informative blog.

Load Cell Manufacturers in India | Load Cell Supplier in India

Ask Vinothini said...

I admired your helpful words. Top class contribution. I really hope you’ll write more. I'll continue looking for.
Compression Load Cell | Shear Beam Load Cell

John said...

rolex replica watches for sale
rolex watches
air max
coach outlet store online
cheap jordan shoes
valentino outlet
nike outlet
fitflops sale clearance
heat jerseys
nike free run flyknit
20170614yuanyuan