Which 433mhz module to order?
- Thread starter Jeff Haas
- Start date
Without knowing more about your application...Here is an option you might want to look at.
$12 not including shipping for the TX/RX pair, and I was in business...I used this product to interface with a PIC I'd programmed to act as a USB Keyboard...the receiver end (and the PIC) are plugged into a USB port..and then I can send "keystrokes" from the transmitter...I've programmed it to send, "WIN-L" (Lock the workstation), "WIN-D" (minimize all windows, restore all windows), "TAB", "CAPS LOCK"...
For the record, I built this to use on my OWN computer, and absolutely did NOT build it to be an elaborate prank device at work which would serve only to frustrate others, and provide HOURS of entertainment.
$12 not including shipping for the TX/RX pair, and I was in business...I used this product to interface with a PIC I'd programmed to act as a USB Keyboard...the receiver end (and the PIC) are plugged into a USB port..and then I can send "keystrokes" from the transmitter...I've programmed it to send, "WIN-L" (Lock the workstation), "WIN-D" (minimize all windows, restore all windows), "TAB", "CAPS LOCK"...
For the record, I built this to use on my OWN computer, and absolutely did NOT build it to be an elaborate prank device at work which would serve only to frustrate others, and provide HOURS of entertainment.
lbenson
Senior Member
If you're just looking to experiment, others have reported success with these, and I have used similar myself: http://www.ebay.ca/itm/Popular-Utility-1pcs-433Mhz-RF-transmitter-and-receiver-link-kit-for-Arduino-/281110165612?pt=LH_DefaultDomain_0&hash=item417378b86c
They need to have antennas soldered on--a section of wire, 17.3cm for 433mhz.
For better control and to increase range, use with rev-ed nkm2401 Radio Encoder/Decoder chips: http://www.techsupplies.co.uk/epages/Store.sf/en_GB/?ObjectPath=/Shops/Store.TechSupplies/Products/NKM2401
A good option for two-way transmission is to use two 14M2s, each using the RFOUT command to a transmitter for TX and one nkm2401 with receiver for non-blocking RX.
Note that these receivers require 5V. Others which are more flexible are available.
They need to have antennas soldered on--a section of wire, 17.3cm for 433mhz.
For better control and to increase range, use with rev-ed nkm2401 Radio Encoder/Decoder chips: http://www.techsupplies.co.uk/epages/Store.sf/en_GB/?ObjectPath=/Shops/Store.TechSupplies/Products/NKM2401
A good option for two-way transmission is to use two 14M2s, each using the RFOUT command to a transmitter for TX and one nkm2401 with receiver for non-blocking RX.
Note that these receivers require 5V. Others which are more flexible are available.
There is a huge difference between modules. Some are dumb with no error correction. Some have onboard serial TTL firmware some use SPI to interface with the Picaxe. Some have network ID's. Some include a configuration utility. Some have an SMA connector for the antenna while others have a PCB wiggle antenna or just use a piece of wire. You generally get what you pay for.
As others have suggested, the more information you can provide about the application/range , and what you can budget for the modules, the better suggestions you will get.
Also, don't rule out 2.4GHz modules. IHAOS has some decent transceiver modules that are SPI based with a Range of > 200 meters up to 1000 meters. About 12 bucks each including a matched SMA antenna. The drawback with these is that an X2 Picaxe is needed for hardware SPI and the Picaxe code is more challenging.
At this point I don't have a specific project but I'm more interested in learning. What got me interested was a fire sculpture I saw at the SF Bay Area Maker Faire last weekend. Here's a YouTube video about it:
http://www.youtube.com/watch?v=Z78yYVYq6mY
They were using these, called a Wixel:
http://www.pololu.com/catalog/product/1336
When I chatted with them, one of the reasons that they liked the Wixel is that it has some sort of encoding built-in, so that electrical noise won't interfere with the control. I got to press the button, the direct control over the fire was impressive! But an individual Wixel is $20.00, and since I've never even tried any wireless control, I figured I'd spend $5.00 or so to get a transmitter/receiver pair just to learn. I've gone through multiple threads here as well as the manual on RF controls. But when I find ebay listings like this one, it made me wonder what the differences were between the modules out there:
http://www.ebay.com/itm/1pcs-433Mhz-RF-transmitter-and-receiver-kit-for-Arduino-project-/261041100836
Even though I've built a number of microcontroller projects, I haven't touched any sort of remote control, so it's all new to me.
http://www.youtube.com/watch?v=Z78yYVYq6mY
They were using these, called a Wixel:
http://www.pololu.com/catalog/product/1336
When I chatted with them, one of the reasons that they liked the Wixel is that it has some sort of encoding built-in, so that electrical noise won't interfere with the control. I got to press the button, the direct control over the fire was impressive! But an individual Wixel is $20.00, and since I've never even tried any wireless control, I figured I'd spend $5.00 or so to get a transmitter/receiver pair just to learn. I've gone through multiple threads here as well as the manual on RF controls. But when I find ebay listings like this one, it made me wonder what the differences were between the modules out there:
http://www.ebay.com/itm/1pcs-433Mhz-RF-transmitter-and-receiver-kit-for-Arduino-project-/261041100836
Even though I've built a number of microcontroller projects, I haven't touched any sort of remote control, so it's all new to me.
If you're looking to send data, and have full control of the RF communications, then buying one of those cheap RX/TX pairs will do the trick...it's not difficult to work with them...I've had a pair talking for about 3 years...just use the qualifier, and a simple checksum and you're in business...(I'm not controlling any fire breathing wolves or anything though...but I am sending around 8 bytes of data every 15 seconds).
If you just want an easy "remote control" setup, then check out the setup in my post above (#4)...I've loved that kit...and $12 is a nice price... especially since the TX comes in a nice key-fob setup...they have different receivers as well...a "Latching" receiver, a "Momentary" receiver, and a "Radio Button" type latching...so check it out. The down-side is, you don't get to know much about the RF protocol...but it does "just work" which is handy...and you don't even need a PICAXE to make it work...
Good luck!
If you just want an easy "remote control" setup, then check out the setup in my post above (#4)...I've loved that kit...and $12 is a nice price... especially since the TX comes in a nice key-fob setup...they have different receivers as well...a "Latching" receiver, a "Momentary" receiver, and a "Radio Button" type latching...so check it out. The down-side is, you don't get to know much about the RF protocol...but it does "just work" which is handy...and you don't even need a PICAXE to make it work...
Good luck!
lbenson
Senior Member
As others have indicated, there are many ins and outs. The TX/RX pair you linked to should work, so you could have everything you need for testing two-way transmission--2 08M2s, 2 TX, 2 RX for under $7US (with this gear, your RX will be "blocking" with 2-way RX, so you can't do something else while waiting to receive). Add two nkm2401s and use 2 14M2s and you should be around $10US, with non-blocking tx/rx.
If you go this route, make sure you have it working wired before you insert the wireless modules.
If you go this route, make sure you have it working wired before you insert the wireless modules.
I can not tell you how fun this has been...keeping a straight face is the hardest part!The thought never occurred to me