Wireless serial digital port maybe?

Can I just plug this into the ez-b, and have another connected to the HC-SR04 Distance Sensor?

http://products.li2.in/69-arduino-bluetooth-wireless-serial-port-module.html

No extra smarts required?

if yes, that would be about $8 per connection. Can it be done cheaper?

No that wouldn't work, that's a bluetooth ttl module, like what connects the ez-b to the pc (which are in the shop here just fyi)

Hoi Dalex,

Waarvandaan ?

PhG: 3000

I am not sure about the distance and exact usage. 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 :)

what you're looking for is a second EZ-B, or a programmable microcontroller (such as arduino). The only issue with using an arduino, is the hardware and cost would be more than a second EZ-B :)

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.

Thanks Hhammoud and DJ for your detailed answers. I guess I'll have to wait a few years till someone shrinks all the functionality of an ez-b down to a single micro-chip and sells it for $1. :)

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.

I was just searching around some more and found this:

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.

I've used those in the past for low speed uart communication. They're great. However will not work for your requirements. As stated before, the ping sensor uses speed accuracy in nanoseconds - by measuring the speed of sound. That device had a maximum speed of 4800 bps.

Also, a servo works in nanoseconds also. You can watch the servo hardware videos on our support page to see how a servo works :)