dalex
Hi Hardware,
I have a HC-SR04 Distance Sensor plugged into my ez-b (or some other device that needs both digital input and output). I want to unplug the connecting digital wires, and in their place, send the digital signals via some kind of RF transceiver. So there would be one module connected to the ez-b, and other connected to the HC-SR04 Distance Sensor, simply performing the function of the two digital wires. Preferably the transceiver should act like a "blackbox" i.e. acts the same as the two digital cables without any extra programming required.
Does such a thing exist? What's the cheapest version of it?
David.
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No extra smarts required?
if yes, that would be about $8 per connection. Can it be done cheaper?
Waarvandaan ?
You need an intelligent transmitters that requires a built in micro-controller to be involved.
The hard way and the cheap one is to add nRF24L01 to a mC of your choice to handle the same functionality .
With some additional programming you may can connect to multiple remote sensors modules if needed.
A lot of article on google for arduino can help in that.
Updated: The easiest but sure not the cheapest is to add another EZ-B as per @DJ suggestion
Also, keep in mind that you would not be able to transmit the actual digital port status from the HC-SR04. This is because the digital ports on the HC work in nano seconds. They also cannot have any delay or latency. You would need to determine the distance at the HC-SR04 with a Microcontroller, then transmit the distance as a value to the other micro or PC.
How an HCSR04 works is by sending a ultrasonic ping. the time it takes for the ping to return can be calculated into a distance. This is all measured by the speed of sound, which is very fast. Any digital to analog frequency transmitter/receiver would not be able to encode/transmit/decode at that speed.
This is probably the cheapest route at the moment:
http://lifehacker.com/5989906/build-your-own-arduino-clone-for-less-than-5
(also adding a bluetooth module).
But it's hardly 'out of the box', which is what I need since I'm not a hardware person.
https://www.sparkfun.com/products/8945
Specifically it says:
"Use these components to transmit position data, temperature data, even current program register values wirelessly to the receiver."
and
"The theory of operation is very simple. What the transmitter 'sees' on its data pin is what the receiver outputs on its data pin."
Surely this does what I was hoping for? Maybe there are some sensor modules that require exact timing between more than one pin (ping sensor?) but to control a servo or read from a single digital wire on a sensor, this should work as far as I can see. Bought a couple to test them out, since they were only a few bucks.
Also, a servo works in nanoseconds also. You can watch the servo hardware videos on our support page to see how a servo works