hi
i’m totally new to micro electronics and robotics etc, but keen to learn.
as a simple first project, i’d like to add a very small blue LED light to a model R2-D2 in a terrarium. ideally i’d like the light to activate if someone approached the terrarium and then switch off, maybe after a short amount of time. Being in a glass bowl, i’ll need to use a battery, but this and the PIR can be hidden under/within a fake rock etc, with a small cable running into the model R2.
the Octopus Hardware Bricks look simple to connect and use, but I have no idea what to buy and how to connect them (i can’t find any instructions online). I don’t want to spend too much money, but individually they look really affordable.
without getting too carried away too soon… the moisture sensor that they do could perhaps notify us if the plants need watering, by activating a different coloured PIR…?!
any help appreciated!
cheers
Ric
Hi,
If you are interested in the octopus, this Arduino Starter Kit is a great place to start because it comes with all the connexion instructions and code examples.
Here is the documentation, it will show you how it is done: robotshop.com/media/files/zip/dodumentation-ef08061.zip
If you want the cost down a little bit, you can buy the board only and the selected sensor.
Freaduino UNO Microcontroller with the bricks of your choice ( 1x PIR, 1x Humidity sensor and 2X led)
We have this battery for arduino that works with this charger
You could also buy a standard Arduino Uno, Mega ou Due board with this shield to make it compatible with octopus modules and it would also provide terminals to add any battery or a regular AA battery holder. The thing is it will be a little bit more complicated if you are totally new to Arduino. Documentation for the shield is not excellent.
Let us know if you have other questions.
Best regards,
thanks Simon!
since i posted, i did a little more research and found that I could simply add the sensor to an LED and a battery and it will work… perhaps using these components:
PIR: robotshop.com/en/mini-pir-motion-sensor.html
LED: robotshop.com/en/various-led … -35pk.html
resistor: robotshop.com/en/resistor-se … k-22k.html
battery connector: robotshop.com/en/9v-battery-snap.html
cables: robotshop.com/en/arduino-jum … -65pk.html
but i’m assuming this will simply switch the LED on when it detects motion and then off straightway…? it might just make the light flicker too much…?
if i did want to try the more extravagant option, with soil moisture sensor etc, so that i don’t have to add the micro controller to the terrarium, is there a way to program this and then transfer the “program” to a much smaller cheaper “thing”…?!
i’ll probably look at getting the starter kit anyway, just to mess around and see what else can be done… i’m an architect/home builder and keen to see how some of this technology can be implemented into our homes 
cheers
ric
Hi,
I did some experimentation with this module not long ago and this module stays on for about 15-20 seconds when it detects movement. After that there is a 5 second reset time to tune on again if movement is detected. This is not what the datasheet says but this is what I experienced. I don’t know if this module supplies enough current for the led but if it does it could be a good cheap option.
We don’t have any solution for the humidity sensor without any programming. If can be done but it requires electronics knowledge and probably pcb design.
Arduino can be very nice for home automation !
Best regards,
cheers Simon, but with any programming, does the micro controller need to remain in the terrarium?
- can the program be added to a simpler, smaller, cheaper device connected to the sensors and LEDs?
ric
Hi,
Yes the micro-controller needs to remain in the terrarium (or be outside and connect sensors with long wires.)
There are really small version of Arduino board that could be great for you application since you don’t require a lot of processing power.
Iteaduino Tiny Arduino
Cuteduino Arduino
Arduino Pro Mini 328
This one even has bluetooth onboard
Bluno Beetle
Sincerely,
excellent, thanks Simon. the first one is cheap enough not to worry about it being in the terrarium, i just need to ensure it’s protected well from water etc (i believe you need to spray/water the plants!), and with it being a glass bowl, i can’t run any cables out of it without it being very unsightly.
thanks again for your help.
hi Simon
i’m going to place an order… having a go! would you be able to help me check that i’ve got the right combination of components please?
so, i’m proposing to go with (from the UK store):
]PIR: robotshop.com/uk/mini-pir-motion-sensor.html/:m]
]soil sensor: robotshop.com/uk/octopus-soi … brick.html/:m]
]micro processor: (like the idea of Bluetooth - messing around with the programming without having to fish it out of the terrarium every time - I assume I can do this with a Mac or iOS, from what i’ve read…?)/:m]
]battery: robotshop.com/uk/lithium-pol … 10mah.html - i think the micro processor has an operating power of 5V so not sure if this is enough power? - can you please recommend?/:m]
]ideally 3mm LEDs: something that can change from white or blue to red if the soil sensor shows that the soil is dry…? robotshop.com/uk/5mm-triple- … -20pk.html - although 5mm, might have to do?/:m]
]a resistor for the LED?/:m]
]cables: can you please recommend some simple plugin/connection cables? i can solder if required./:m]
]anything else i need?/:m]
thanks
ric
Hi,
- PIR: robotshop.com/uk/mini-pir-motion-sensor.html -> Not the best choice for you application, it needs to work at 9V and you chose a 3.7 V battery.
This one should do but it does not stay on 20 seconds but more around 3 seconds: robotshop.com/uk/pir-motion-sensor-arduino-compatible.html
- soil sensor: robotshop.com/uk/octopus-soi … brick.html -> Wil work but I am not sure the cable is included.
This one comes with a cable: robotshop.com/uk/dfrobot-moisture-sensor.html
- micro processor: (like the idea of Bluetooth - messing around with the programming without having to fish it out of the terrarium every time - I assume I can do this with a Mac or iOS, from what i’ve read…?)
According to the documentation it can be done but we have never tried. Probably form a mac but not sure about IOS because you need arduino program.
- battery: robotshop.com/uk/lithium-pol … 10mah.html - i think the micro processor has an operating power of 5V so not sure if this is enough power? - can you please recommend?
Not enough, you will need something with 5V or more and 110 mah is way too low, it will only last a couple of hours ( if you dont use the leds much).
-Best option: Go with 4 x AA battery holder soldered directly to the board.
robotshop.com/uk/4xaa-square … cover.html
robotshop.com/uk/battery-hol … =RB-Cyt-49
-Option 2:You could always go with a lipo battery but you will need to make a connector for the microcontroller and also buy a charger
- ideally 3mm LEDs: something that can change from white or blue to red if the soil sensor shows that the soil is dry…? robotshop.com/uk/5mm-triple- … -20pk.html - although 5mm, might have to do?
a resistor for the LED? --> The classic is 220 ohm but maybe you will need to double check for this led.
cables: can you please recommend some simple plugin/connection cables? i can solder if required. --> Apart from the led maybe, you should not need any other cable with the parts that I proposed. Because there is no connectors on the bluno you will have to cut the cables included with the sensor and solder them to the board but you should have everything.
anything else i need? You should be all set.
If you have the chance, post some pictures and information of the evolution of the project !
Best regards
