I am a C# developer with no experience with microcontrollers. Now I want to build a small device which should water my garden.
This device should do nothing else than except commands over WiFi (802.11b or better) to switch 9 relays (1x220V + 8x24V). And it should be as cheap as possible.
I looked at several mainboards GHI offers and what I like most so far is the Cerbuino. Compared to the Cerberus (and Hydra) I wouldn’t need the USB Client DB Module and the XBee Adapter Module (it has to run 24/7 without a computer). I like the plug and play design from Gadgeteer. As I have almost no electronics experience this is exaclty what I need.
Now to my questions:
When do you estimate to be able to ship the Cerbuino?
How long will the firmware need to be finished? Can I do anything without it?
What else do I need to connect it to my WiFi? Can you give me an url to a good XBee WiFi module?
Are there any bigger relay modules/shields available? I would need 3 modules with 4 relays each. Can I use 3 such modules at the same time with the Cerbuino? It does have 3 Y sockets, so it should be possible.
Or should a beginner refrain from the Cerbuino for now and take a Panda II? Hydra and Spider are to expensive, there I would prefer a Netduino (Go) instead.
Another pro of the Cerbuino is the microSD slot. Currently I plan to make a small application on my webserver which I can use to control the watering system. If the Cerbuino is strong enough, then I could also move this app to the Cerbuino completely. But this would just be a pet project and is no requirement.
For what you describe, the Cerbuino is “eventually” going to be perfect for. That being said, it will probably be a few more months before it will be solid enough to be able to do so without any problems. If you want to help beta test this board while building your project then jump into the deep end with us. Given that you are new to micros and we want your first experience to be great then I would recommend you go with a Panda-II if you don’t want to go with a Spider or Hydra. You’ll find that the Panda-II has more than enough power to do what you are trying to accomplish.
Another option you might consider… Since you can normally replace one Gadgeteer mainboard with another with almost no code changes, you might consider getting a Spider or Hydra as a primary development board and then when the Cerbuino is ready then you can just replace your more expensive board with it for your “production” app. Then you still have your other board to start the next project with!
Let us know if you need any other help along the way!
You can’t compare Hydra/Spider to any other devices you mentioned. This is like saying: a Ferrari costs more than a Fiat so I will buy a Fiat Yes both have 4 wheels and both will take you to work.
Thank you for your answers! Then I will order my Cerbuino as soon as it is available. Delivery will probably take longer than the firmware anyway.
[quote=“Gus”]
You need this http://xbee.codeplex.com/[/quote]
I was wondering what hardware I should use.
Also if the WiFi library is not finished yet, when will it be? I’m fine with using beta code, but I want to connect to my existing 802.11 network and not build a new 802.15.4 or whatever other network which would need additional hardware connected to my other machines.
[quote=“Gus”]
I would suggest not adding so many relays to the system. Instead, use Load Module and connect your own relays.[/quote]
If the load module can switch up to 50V/3A then this should be fine for the small things. But it only has 7 connectors and I also need to switch one big pump with 220V. Should I then use 1 load and 1 relay module?
[quote]I was wondering what hardware I should use.
Also if the WiFi library is not finished yet, when will it be? I’m fine with using beta code, but I want to connect to my existing 802.11 network and not build a new 802.15.4 or whatever other network which would need additional hardware connected to my other machines.
[/quote]
Xbee is simply a wifi connection over serial port. so it is not that hard to write code for.
I meant to use the load module to control any relay you may find suitable, not to use the module directly.
This is an open source project, so it will be done when it is done. It is summer in my part of the world, which is typically not a productive time for these kinds of projects. If you’re looking to water your lawn this season, I would suggest going with an alternate design.
Xbee is simply a wifi connection over serial port. so it is not that hard to write code for.[/quote]
I guess I will go with the RN-XV WiFly Module. This should fit onto the Cerbuino.
Unfortunately I learned electronics only for 1 year in school and this was about 20 years ago. I can solder a plug onto some cables but thats about it. So I was looking for a simple module which I can plug in and it would work.
But I also found a relay board which is meant to be connected to a computer via RS-232 or USB. I guess I will try to connect this board to the Cerbuino and communicate via an UART.
Given that you are new to micros and we want your first experience to be great then I would recommend you go with a Panda-II if you don’t want to go with a Spider or Hydra. You’ll find that the Panda-II has more than enough power to do what you are trying to accomplish.