khoj
Posts: 2
Joined: Mon Oct 09, 2017 8:23 pm

RP 3 or Zero W - which one is enough for my project?

Mon Oct 09, 2017 9:23 pm

Hello,

I am totally new to Raspberry Pi so please excuse me if I don't yet know all the obvious things. I am looking for guidance on what all components I would need to buy to do a little project I am planning to build using RP.

The project I have in mind:

When an object comes closer, take a picture, store it on a SD card, send it to a remote server, receive the confirmation from the remote server and finally lit up a LED.

Little more technical details/steps:

- A camera attached to RP will take a picture when an object is detected by the IR sensor.
- The picture doesn't have to be a very high resolution one, but camera should be able to take clear pictures in low light conditions.
- Picture will first needs to be stored on an on-board SD card and then sent to a remote server (somewhere on internet) over HTTP (via REST API POST call).
- The response from the remote server will be a very small JSON document that will be processed/read and the value of one of key in the response document will be stored on SD card.
- Once everything is successfully completed, a small LED light will be lit to indicate the success.


My questions:

Q1: Will RP Zero W be powerful enough for this project or would I really need the extra power that RP 3 provides?

I would like to have the whole round trip (object coming in proximity sensor's field to LED lighting up) to not take more than 10 seconds. Keeping in mind that once picture is posted to the remote server, it takes about 5 seconds to receive the response document. Meaning, would like RP side of things to not take more than 5 seconds.

Q2: What other components would I need. Here is what I am thinking:
I don't have:
- Small camera

I already have:
- Infrared Obstacle Sensor (I have one of those cheap 4-pins avoid sensor module)
- Small LED light
- USB (if using RP3) or wireless/BT enabled (if using RP Zero W) keyboard and mouse
- microUSB cable
- microSD card
- An external monitor or TV
- HDMI or VGA cable to connect RP to monitor
- A small breadboard
- Several jumper wires

Is that it or did I miss something? Would I need any specific cable/wire/adapter to connect any of these components to RP? Which camera module should I buy? I will highly appreciate if you can tell me the exact component model (and maybe place to buy too). I have been Googling around and getting lost.

Thanks you all in advance for helping me start exploring RP and get going with this project.

W. H. Heydt
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Joined: Fri Mar 09, 2012 7:36 pm
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Re: RP 3 or Zero W - which one is enough for my project?

Tue Oct 10, 2017 4:48 am

At a quick glance, a Pi0 or Pi0W should work. However, it is far easier to work with a Pi3B. This is especially true if you are going to use any G{IO pins (such as controlling a LED) as the Pi3B has the header block installed at the factory.

So...my advice would be to get your project working with a Pi3B and then--should you wish--shift it to a Pi0/Pi0W. After that you can redeploy the Pi3B for some other project.

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B.Goode
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Location: UK

Re: RP 3 or Zero W - which one is enough for my project?

Tue Oct 10, 2017 7:03 am

Q2: What other components would I need. Here is what I am thinking:
I don't have:
- Small camera
Both the RPi3 and the PiZero[W] models have the connector for the dedicated Raspberry Pi Foundation camera module.

So the Raspberry Pi Foundation camera module would be a simple choice that is known to work.

https://www.raspberrypi.org/products/camera-module-v2/

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hansotten
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Re: RP 3 or Zero W - which one is enough for my project?

Tue Oct 10, 2017 7:16 am

" but camera should be able to take clear pictures in low light conditions."

This rules the Raspberry Pi Camera Module out I fear. The NOIR variant may work better here, but with the obvious IR coloring.
http://duinorasp.hansotten.com for Raspberry Pi and Arduino and ESP8266
http://retro.hansotten.nl for retrocomputing with the 6502 cpu

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Gavinmc42
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Re: RP 3 or Zero W - which one is enough for my project?

Tue Oct 10, 2017 8:02 am

If you are totally new start with the Pi3, the Zero's are not a beginners Pi's.

If it is a fixed, Ethernet cable version you don't even need a Pi3, a B+ or Pi2 will work.
If you need WiFi then Pi3. Lowest power batter version then Zero W.

We have been playing with Cameras now on Ultibo.
Ultibo WiFi is not working yet but a PIR sensor could turn on power to the Pi and the first image can be captured in about 3 seconds.
This would save battery power for portable versions. Game camera etc
An alternative way to do WiFi, is use a WiFI module ESP8266 or similar to the uart on the Zero.

For night time, PIR turns on Pi plus IR LED, you need the NOIR camera.
For daytime, a solenoid or RC servo makes a IR block filter move in front of the lens.

If you get a 3 and Zero W you can watch images from the Zero W on the 3.
Use Raspbian to get this going and to get familiar with Pi's
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

khoj
Posts: 2
Joined: Mon Oct 09, 2017 8:23 pm

Re: RP 3 or Zero W - which one is enough for my project?

Tue Oct 10, 2017 6:01 pm

Thanks you all for your input. Sounds like I should go with Pi3B and a NOIR camera.

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