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Which is the right hardware for me?


#1

Please let me know the board/display i need to buy to fulfil the following requirements

  1. I need a 7 inch display where i wish to show some buttons.
  2. Need PWM so that i can give variable voltage output (0V to 5 V output)
  3. I will also be using a piezo module, thermometer module and a variable resistor module.
  4. Cost effective

Please let me know the details so that i can purchase the same.


#2

All you need is here, I recommend FEZ Hydra
http://www.ghielectronics.com/catalog/category/265/

The 7" display will be there in about couple weeks.


#3

Thanks for the speedy reply. I am a .NET Architect. I am new to embedded systems so pardon my ignorance. I have couple more questions

  1. I guess i will not get a 5V output from any of the Fez boards. Am i right? they are all 3.3 V output. in that case how would i get 5V output?
  2. which 7 inch display should i use? can i use any 7 inch display? for e.g. there is a 7" tft touch display for $100 from ghi. can i purchase that.

Following i guess are the things i need to order then… I am in india that is the reason i am writing the list of items here. sorry about the list…

  1. Fez Hydra
  2. USB Client SP Module
  3. 7 inch display

Is there anything else i am missing?


#4

Ok I see now. Think if this as building a PC. You need motherboard (mainboard), power supply, and monitor, and maybe sound card :slight_smile:

You need FEZ Hydra (mainboard) then you need the better power supply since you will add a large display. In embedded world, a 7" display is considered very large! So go with USB Client DP Module.

You may want to add a Button and LED7R modules to get you started learning. Of course you can pick and choose of any of the other modules, including a 3.5" display available today. If you need sound, add the music module.

As for the 7" display, it is not available today but will be in few weeks.


#5

Thanks a lot.

I already got a fez panda 2 kit and have experimented with it. I was able to do the entire project on that except i had the following issues

  1. It is a very small screen and does not support bitmap and higher graphics
  2. did not give me a 5 V output.

What about the 5 Volt output? Any chance i can get around that?


#6

Do you mean 5V power or 5V IO levels? All sockets provide 5V power. If you must have 5V IO levels then you’ll have to use a transistor to amplify the 3V3 signal.


#7

I mean 5 V I/O. I will need to set the voltage output using the touch screen and then the same voltage output power will be used to power a laser for example.
Is there a article or something that tell how to convert the 3.3 to 5 v?


#8

Even if you have 5V out on a processor pin, you can NOT use the processor pin to power relays, laser diode…etc. Processor pins are only to “signal” things and not to “power” things.

You can either use a relay module or use this “load” module http://www.ghielectronics.com/catalog/product/364


#9

Here’s the usual circuit.

Where Vin is your IO and Vout is 5V. Also, you’ll want to add a 10K resistor between Vin & the transistor. The other resistor can be 1K. Vcc is your 5V source.


#10

@ ianlee74 the load module does just that and there is 7 of them :slight_smile:


#11

I understand but the load module isn’t yet available. If he wants to go ahead and get something done this will work in the meantime. Besides, everyone needs to learn this :wink:


#12

You didn’t indicate what kind of transistor it is, teacher.


#13

Sorry, I usually use 2N2222 or 2N3904.


#14

2N2222 can switch a shocking (hah! see what I did there?) amount of current for such a small, ubiquitous, cheap, easy-to-interface device. If you can’t find them for under $0.10 per, you’re doing it wrong.


#15

I bought a couple hundred off eBay last time for under $0.03 each :wink: