cjfoss
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Joined: Wed Nov 27, 2013 2:14 am

Trade-offs between RaspPi and Arduino

Mon Dec 02, 2013 4:01 pm

I plan on transmitting roughly 10Mbps of CR1000 sensor data, as well as image files from a Logitech webcam. I was originally planning on using the RaspberryPi model B board, however, I would like control of power consumption, as to minimize it in times of low usage. This feature is not available with the RaspberryPi board, but is common with most Arduino's(say the mega 2560). I also plan on using a Wifi dongle to send and receive commands from a computer up to 50m away.

Since I need to be able to drive the camera and be able to send/receive commands and data, what are the trade offs between the RaspberryPi Model B and Arduino Mega 2560? One clear difference I was able to notice was that the Rpi has much more memory and processing power, will this drastically affect transmission speeds and throughput in my application?

hunternet93
Posts: 336
Joined: Mon Dec 12, 2011 4:34 pm

Re: Trade-offs between RaspPi and Arduino

Tue Dec 03, 2013 3:15 am

It sounds like the Raspberry Pi or a similar full-fleged computer would be the way to go, using a USB webcam with an Arduino and streaming the video would be difficult. You'd need to write the driver (unless there's one already), write a highly efficient video transcoder and streamer, and have to figure out multitasking. I doubt the Arduino would have the processing power to keep up. The RPi Model A has significantly less power consumption, you could look into using that.

cjfoss
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Joined: Wed Nov 27, 2013 2:14 am

Re: Trade-offs between RaspPi and Arduino

Tue Dec 03, 2013 3:43 am

I actually only need snap shot pictures from the webcam, does that change things?

Also if I went with the Model A is it possible to put the Ethernet 10/100 connector on it and the 2xusb connectors?

ame
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Location: New Zealand

Re: Trade-offs between RaspPi and Arduino

Tue Dec 03, 2013 3:58 am

cjfoss wrote:I actually only need snap shot pictures from the webcam, does that change things?

Also if I went with the Model A is it possible to put the Ethernet 10/100 connector on it and the 2xusb connectors?
Do you know how to take a snapshot from a webcam using Arduino? If you do, then you can decide the answer for yourself.

You can not add the Ethernet and 2xUSB sockets yourself. It needs another chip and it would be a pain to solder.

You can add a USB hub to the Model A, and plug a USB->Ethernet adapter into it, plus a couple of other USB devices, but why would you want to do that instead of buying a Model B?

hunternet93
Posts: 336
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Re: Trade-offs between RaspPi and Arduino

Tue Dec 03, 2013 4:04 am

The Ethernet/USB hub chip in the Model B is the reason the Model B uses more power than the Model A, if you need Ethernet then you're better off with the Model B. Since you mentioned Wi-Fi in your original post I assumed you would use it to transfer the data.

The Raspberry Pi and the Arduino are two very different devices, the Pi is a full Linux-based computer while the Arduino is a microcontroller development platform. Both are very useful in their particular areas, what you'd like to do is solidly in the Pi's (or other computer's) domain.

cjfoss
Posts: 8
Joined: Wed Nov 27, 2013 2:14 am

Re: Trade-offs between RaspPi and Arduino

Thu Dec 05, 2013 9:41 pm

I would like to use the model A because it has half of the power consumption than the model B board.

Regardless, the devices i plan on connecting to either board can be connected using a Rs232 to USB( a Campbell Scientific Datalogger with transmission rates up to 10Mbps), USB(a logitech webcam for snapshots), and possibly two other free floating analog sensors?

Will the model A board be able to handle this?

thanks

hunternet93
Posts: 336
Joined: Mon Dec 12, 2011 4:34 pm

Re: Trade-offs between RaspPi and Arduino

Thu Dec 05, 2013 10:01 pm

cjfoss wrote:I would like to use the model A because it has half of the power consumption than the model B board.

Regardless, the devices i plan on connecting to either board can be connected using a Rs232 to USB( a Campbell Scientific Datalogger with transmission rates up to 10Mbps), USB(a logitech webcam for snapshots), and possibly two other free floating analog sensors?

Will the model A board be able to handle this?

thanks
Yes, it should work fine. I'd recommend using a powered USB hub for all those USB devices. The model A doesn't have onboard Ethernet (which is part of why it uses less power), so you also will need a USB WiFi or Ethernet module.

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ZacharyI123
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Re: Trade-offs between RaspPi and Arduino

Thu Dec 05, 2013 10:25 pm

cjfoss wrote:I would like to use the model A because it has half of the power consumption than the model B board.

Regardless, the devices i plan on connecting to either board can be connected using a Rs232 to USB( a Campbell Scientific Datalogger with transmission rates up to 10Mbps), USB(a logitech webcam for snapshots), and possibly two other free floating analog sensors?

Will the model A board be able to handle this?

thanks
You will need a USB hub for two USB devices as the model A only has one (whereas the model B has two).

The analogue sensors will connect to the GPIO.

They the A can handle this but rather than powering a model A and a USB hub, you could just power a model B without a USB hub!
Don't be mean, I'm only thirteen 8-)

ame
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Joined: Sat Aug 18, 2012 1:21 am
Location: New Zealand

Re: Trade-offs between RaspPi and Arduino

Fri Dec 06, 2013 12:33 am

cjfoss wrote:I would like to use the model A because it has half of the power consumption than the model B board.
The reason it has half the power consumption is because the Ethernet chip (with 2 USB ports) is not present. If you buy a model A and then plug in a hub and an Ethernet adaptor then your total power consumption will go up to the same level as a model B. I'm not sure this makes much sense.

If you use a model B then you can connect wired Ethernet immediately, and your serial port adapter and webcam. The (future) analog sensors could be connected to GPIO somehow (maybe I2C or similar).

Anyway, since you have neither I think it's more important to buy either a model A or B and try it. I suggest the model B, to get things working, then you can look at optimising it later (perhaps by using a model A, but it may turn out that a model A is unsuitable).

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