chungenhung

Need this to act as a switch to turn a computer on/off. The wires will be connected to the motherboard on/off headers. These headers simply need to be shorted momentarily, and the PC would then turn on.

 

Right now, I am using a relay switch to do this, but I believe an IC or transistor would be able to do it too. Actual relay switches are expensive compared it transistor.

 

The current flowing through the transistor would be very small, and thus an actual relay switch is simply a waste.

 

How would I go about using transistors? I have 8 computers that I want to be able to control using Netduino, would it better to get an IC chip instead?

 

I don't think I need resistors, as I am simply completing the circuit (just like there is no resister in a PC on/off switch on the case).

 

Since the transistor should normally be OFF, I believe I need a NPN type. The transistor needs to be OFF when there is no current.

How would I connect the wires? Would appreciate it if you can link me a sample transistor, and a short code snippet.

 

Sorry, I am new to IC and transistors, and don't really know how to make them work.

In need of a 12V wall adapter with exposed PINs to power this

http://www.amazon.co...&pf_rd_i=507846

 

Note that the board does not use a barrel type connector, but simply takes 2 wires to be screwed down.

Is there a wall adapter with exposed wires (without the connector)? Or I would probably just need to buy a regular wall adapter and cut off the barrel connector.

 

 

Flashed the device to 4.2.0.0. When I attach the device Blue and white power light comes on. I was able to use MFDeploy to ping and check "Device Capabilities". A little while goes by, the ACT, 100, FDX lights flash, then off. The Blue light also goes off. Now, I can no longer access the device in MFDeploy. MS Development Studio also report having problem communicating with the device. What's going on? Note that, if I reconnect the device again, I would be able to access it in MFDeploy, then a minute later, the blue light would be off, and I won't be able to access it again.

Downloaded the 4.2 firmware from http://forums.netdui...-firmware-v420/ Used SAM-BA v2.11 as instructed in the "Getting Started with Netduino" book, pg 76-78. After the firmware is sent to Netduino, I did a compare file to make sure the firmware is really uploaded. The program says Match Exactly. Unplugged and plugged in as instructed in the book. Opened up MFDeploy tool. The device is not showing up under "USB". Went to Device Manager in Windows, and now the Netduino device have an ! mark next to it. What do I do now? Hopefully the netduino plus is not bricked! The netduino device had Micro Framework 4.1 before. I was developing something using Framework 4.2, that is why I did the firmware upgrade.

Got this http://www.makershed...x4_p/mkad25.htm I would like to be able to read out what numbers got punched in, then use that number to control a servo. Example: User keys in 5487. It will translate to 5.487 seconds. The servo will be in a starting position. It moves to ending position, then, waits 5.487 seconds, and moves back to starting position. How can I do this? Can anyone provide me help or teach me?