SparkFun Electronics - RF Link 2400bps Receiver

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Product Info

RF Link 2400bps Receiver - 434MHz

sku: WRL-08949

Description: Sold as a receiver only. This receiver type is good for data rates up to 2400bps and will only work with the 434MHz transmitter. Multiple 434MHz receivers can listen to one 434MHz transmitter.

This wireless data is the easiest to use, lowest cost RF link we have ever seen! Use these components to transmit position data, temperature data, even current program register values wirelessly to the receiver. These modules have up to 500 ft range in open space. The receiver is operated at 5V.

We have used these modules extensively and have been very impressed with their ease of use and direct interface to an MCU. The theory of operation is very simple. What the transmitter 'sees' on its data pin is what the receiver outputs on its data pin. If you can configure the UART module on a PIC, you have an instant wireless data connection. Data rates are limited to 2400bps.

The typical range is 500ft for open area.

This receiver has a sensitivity of 3uV. It operates from 4.5 to 5.5 volts-DC and has digital output. The typical sensitivity is -103dbm and the typical current consumption is 3.5mA for 5V operation voltage.

Features:

434 MHz Operation
500 Ft. Range - Dependent on Transmitter Power Supply
2400 bps transfer rate
Low cost
Extremely small and light weight

Documents:

KLP Walkthrough Tutorial
Good AVR Tutorial
Receiver Datasheet
Another Very Helpful AVR Tutorial - Thanks Eric Forkosh!

Pricing

	748 in stock backorder allowed

$4.95	price
$4.46	10-99 (10% off)
$3.96	100+ (20% off)

	quantity

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Comments

5 comments

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j1432

+3.7

| January 10, 2009 at 5:35 PM

Gave this board a try.

Pros:
* It is really easy to use.
* Whatever data you put onto the transmit pin more or less comes out of the RX pin on the other unit.
* You can't beat the price.
* These modules are pretty small.

Neutral:
* The latency of this board is about 10ms.

Cons:
* The data coming out of the RX pin is inverted.
* I tried sending a 10ms pulse every 400 ms. What I received was a 58ms pulse every 400ms. The pulse length shortened to 52ms with a 100ms interval. When I went down to a 10ms on 10ms off signal everything worked properly.
* The transmitter seems to only send a signal when you drive it high. When it is being driven low or is off, the receiver outputs static.

Overall, I would say go for it if you are OK with scanning your data for proper packets of data. The price is awesome.

	by j1432 +3.7 \| January 10, 2009 at 5:38 PM 0
One slight correction to my previous comment: If you are sending regular serial data or a signal such as the 10ms on 10ms off pulses that I described, the receiver will output a clean signal. It doesn't output static when you drive the transmitter low for short periods.

	by j1432 +3.7 \| January 10, 2009 at 6:13 PM 0
OK... Last comment. The data appears to correct itself from inversion when you send it at a faster rate than the pulse trains that I was sending before. The 10ms on and 10ms off might have been correct but since the two halves were of equal size, I couldn't tell.

RobBrownNZ

+3.8

| June 8, 2009 at 3:46 AM

I tried this board, and it was rubbish. There was a continuous stream of noise data from the receiver whether or not the transmitter was active. When I was transmitting data, the data would be received but with such high error rates that it was unusable. I made a dipole antenna, with balun, so the aerial shouldn't be the problem. Maybe I just live in a noisy area.

Then I tried the "4800bps" receiver, WRL-08950 (https://www.sparkfun.com/commerce/product_info.php?products_id=8950). What a difference! Data is clean with very few errors (e.g. an error every few minutes).

If you're looking for a link that doesn't give you heartburn, I'd recommend that you spend the extra $1 and get the WRL-08950 one.

Semaphore

+1.1

| January 6, 2010 at 8:10 PM

These boards are awesome for a cheap way of sending data at low speed. Just be warned that if you are not sending any data, or disconnect the transmitter, that it will begin to pick up all kinds of noise.

I worked around this by having my receiver check for a certain number of consecutive "start bits", and only accept the data if they're all there. After that you can use it like a plain ol' UART, except wireless. Woot.

They even label all the pins for you, thanks guys!