Simple RF M4 Receiver - 315MHz Momentary Type

by Shaputer on Tue Mar 19, 2013 3:20 pm

I got this receiver and the Keyfob to go with it. It works but I have to be really close to the receiver with the Keyfob for it to work. I have no garage door opening or any other 315Mhz device around to interfere. Why is the range only a couple of inches ? I stretched the wire on the receiver out all the way. I powered the receiver with 9V and the VT is going to 5V.

Could someone tell me how to get better range than a couple of inches ? I'm using the transmitter and receiver to control Adafruit motorshield DC motors. THANK YOU ~! :D
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by adafruit_support_bill on Tue Mar 19, 2013 4:13 pm

Can you post a photo of your setup? Make sure that the antenna wire is clear of any possible sources of interference.
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by Shaputer on Tue Mar 19, 2013 4:36 pm

Well that's kinda of hard to do because it's connected to the car I'm using. Here's a picture anyway. The antennae is the skinny wire on the far left pointing straight up. I don't know what's interfering with the antennae that's why I asked. What would interfere with it ? It's hooked up just like the Adafruit example with the D0-D3 on the receiver going to pins 14-17 on the Arduino.

The other transmitter device you see in the picture is for video and is not connected to anything at the moment. It's 2.4Ghz transmitter. THAnks !
Last edited by Shaputer on Tue Mar 26, 2013 11:59 am, edited 1 time in total.
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by adafruit_support_bill on Tue Mar 19, 2013 6:01 pm

I hooked one up here to test. I had to go into the next room before the signal got dodgy. Some metal shelving between the transmitter and receiver seemed to cause the most signal loss.

Try a fresh battery in the transmitter. If that doesn't work, we can try replacing the receiver.
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by Shaputer on Wed Mar 20, 2013 11:05 am

Well that was not a well spent $12. The new batteries didn't work. I just received both the receiver and keyfob from Adafruit on 3/15/2013 and I only used it Monday and Tuesday of this week so I hope the batteries last longer, but still only inches in range. Thanks !

Oh, just to let you know that I had fully charged batteries on the bot with the receiver and arduino.
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by adafruit_support_bill on Wed Mar 20, 2013 11:16 am

OK then, contact support@adafruit.com with a link to this thread and ask for a new receiver.
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by Shaputer on Mon Mar 25, 2013 4:20 pm

Unfortunately the replacement does the same thing. Range is a few inches with strong dependable behaviour. I removed it from my robot and connected it to Adafruit boarduino and an LED and it acted weird at about 15-20 ft with no obstructions. Perhaps I have too much going on in my house for this frequency rf module. Would you think a 433MHz rf set would work better ? Do you have any suggestions on how to get this to work ? THANKS !!! :cry:
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by adafruit_support_bill on Mon Mar 25, 2013 5:09 pm

I removed it from my robot and connected it to Adafruit boarduino and an LED and it acted weird at about 15-20 ft with no obstructions.


So the range improved off the robot? Sounds like maybe some interference - possibly from some circuitry on the robot.
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by Shaputer on Mon Mar 25, 2013 5:25 pm

If 15-20ft is normal than I'll have to try something else. That's kinda lame for my purposes. I have a Minty-Mote remote set in a toy robot that gets much better reception using just an H-Bridge to control the motors. I can maneuver this around the corner and into another room without moving.

http://www.instructables.com/id/The-Big ... ontrolled/

It only transmits one press at a time.

But, this bot has 4 motors to run. That's why I used the motorshield this time.
The only circuitry is Arduino and Adafruit motorshield. Nothing else. Esplora and Xbee seem to be my only alternative for decent wireless. Expensive though.
Last edited by Shaputer on Tue Mar 26, 2013 12:00 pm, edited 1 time in total.
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by adafruit_support_bill on Mon Mar 25, 2013 7:13 pm

From the testing I have done here, things start getting iffy around 20 feet in my lab - more like 25-30' away from all the equipment. That's similar to what I get from a wireless PS-2 controller.

There was a post on the Adafruit blog a while back about a robot remote control made from a PS-2 controller and XBees.
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by Shaputer on Tue Mar 26, 2013 11:59 am

Wonderful. Esplora and Xbee sound much simpler. Plus it's really hard to find anything on this message board. Does this keyfob work with anything else ? Please directly answer this question.........
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by adafruit_support_bill on Tue Mar 26, 2013 12:35 pm

The remote works with the T4, M4 and L4 receivers.

http://www.adafruit.com/products/1097
http://www.adafruit.com/products/1098
http://www.adafruit.com/products/1096

The PS2/XBee blog post I mentioned can be found by searching the blog (not the forum) with"PS2 Xbee".

http://www.adafruit.com/blog/2012/04/23 ... ontroller/
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by Shaputer on Tue Mar 26, 2013 12:50 pm

Right, just Adafruit 20ft receivers. You can get both momentary and latching with the M4 depending on how program the Arduino sketch. Just need something that measures it's range in meters and not feet. Most do. I see you don't have any range documented for your units and it does work exactly the way Lada Ada demonstrated it. Technical details are on the decoder chip and not the radio circuitry. Don't care much about the decoder chip. All basically the same. Support doesn't offer any solutions or advice on possible longer range capabilities such as using antenaes ...........well it's worth the $4 I guess. Will save it for the kids and follow my own advice. esplora and xbee. Thanks anyway.
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by adafruit_support_bill on Tue Mar 26, 2013 1:22 pm

If you are not satisfied with your purchase. Please contact support@adafruit.com for a refund. Be sure to include a link to this thread.
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Re: Simple RF M4 Receiver - 315MHz Momentary Type

by Shaputer on Wed Mar 27, 2013 10:15 am

Not worth the trip to the post office to return the stuff. Cost more in gas and postage then the stuff is worth.
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