Low power radios

Community General Discussions
1

I would like to start a discussion revelent to low power (cost) radios and embedded electronics such as robots, environment sensing, and remote control of household or shop equipment. I am NOT an RF engineer.

To date I have experimented with:

  1. Raw, very cheap, tx or rx modules and transceivers
  2. NRF24L01 transceivers
  3. Hope RTM69 transceivers
  4. ESP8266 Wifi modules

I also have some other WIFI boards (Digilent PmodWiFi) that are still untouched.

Again, antenna and RF design are NOT part of my skill set!!!

2

nrf24l01
My experience with the NRF series is mostly transmitting sensor data from a robot to a base station. Usually about 10 messages per second. I have found that transmission quality quickly deteriates after 10 meters and implementing retransmit algorithms to be difficult.

There are quite a few flavors of the NRF24L01 available today ranging in price from less that $2.00 to $30.00 with various antenna options.

On a side note, how do you get the forum to reconize paragraphs. This message should contain 3 paragraphs.

3

Bluetooth

Bluetooth it’s a nice kind of wireless control which it’s embedded in most of cell phones, serial chip HC05 costs around 3-6 dollars. The range of bluetooth varies from 1m to 100m, cell phones usually have a range of 9-14m in open field.

Bluetooth has various implementations, but the most common it’s 2,4GHz, class 2, range about 10m, version 2, which draws about 12mAh, and about 30mAh for continuous use(tested myself). Nice things about bluetooth it’s that error checking, pairing, channel hopping, example code, simple security and other software it’s already available. HC05 chips often even have a status led which helps to debug.

Going to buy nRF24L01+ chips too:)

4

Add < p > before start

Add < p > before start paragraph and close with < / p > the paragraph in html editor, without the spaces between the symbols

5

html control codes
You manually insert the "< p >"text!! I’m looking at the “Input format” options. It might accept two RETURNs to denote a paragraph.

6

Bluetooth
Thanks for adding the Bluetooth to the mix. I have been unable to get started with Bluetooth. Went to a ST Micro ARM demo where they used their Arduino compatible board to control a Bluetooth. I don’t own a smart phone to do the demo.

7

I like Bluetooth LE
I like Bluetooth LE (LowEnergy) for robots.

Adafruit makes a BT LE breakout board using the nRF8001 chip. This board is around $20. This should send and receive data out to about 10 meters. If you don’t have another gadget with BT 4.0, which includes BT LE, Adafruit sells a very small USB device. It should work on Window 7+ without needing a driver, and can work under Linux for about $11.

You might be able to get these things cheaper on eBay.

Also you can write apps using BT LE without going through the legal hoops you need under iOS.

Adafruit also has other interesting BT devices: one simulates a small keyboard, another is a standard serial link with the outputs lined up so it can also program an Arduino over this.

I like BT because. Most of the hard work is already done for me.

Have a nice morning.