USB Bluetooth dongle for Arduino Uno + battery power questions ?

Hi there, I had a look at previous posts but couldn't find exactly what I am looking for. I have an Arduino Uno which is connected to about 8 sensors of different types via USB to the PC. I was wondering if there was a simple way of just plugging in a USB Bluetooth dongle to replace the USB cable and if so how could I power the Arduino in the absence of a USB cable ? It would have to be battery powered as I wont have mains near the arduino (thus the BLuetooth). What sort of power consumption might I be looking at and whats the longest lasting battery power option (and smallest physical space) ? cheers, Gus

to about 8 sensors of different types

Without knowing the specifications of the sensors, how can we estimate current requirements? Look at the data sheets and try to find the specs for power for each. Look at the Bluetooth module data sheet, too. Add the currents up. Add about 50mA for the Uno. Multiply The sum of sensor currents plus Uno and Bluetooth current by the number of hours that you want the project to run between battery charge or change. That is the ideal minimum amp hours (Ah) for the battery (1.5 to 2X more realistic). If you want long battery life you will need to ditch or modify the Uno and be able to power the sensors and Bluetooth off (or sleep) while sleeping the processor.

groundFungus: Without knowing the specifications of the sensors, how can we estimate current requirements? Look at the data sheets and try to find the specs for power for each. Look at the Bluetooth module data sheet, too. Add the currents up. Add about 50mA for the Uno. Multiply The sum of sensor currents plus Uno and Bluetooth current by the number of hours that you want the project to run between battery charge or change. That is the ideal minimum amp hours (Ah) for the battery (1.5 to 2X more realistic). If you want long battery life you will need to ditch or modify the Uno and be able to power the sensors and Bluetooth off (or sleep) while sleeping the processor.

Let me rephrase my questions.

  1. Is there a way of just plugging in a USB Bluetooth dongle into an arduino uno to replace the USB cable to get data from the arduino into the PC ?

  2. What is the best (best = occupying the smallest space and last longest)and most efficient way to supply 5V (500 ma max) to the arduino via batteries if the USB port is occupied by a Bluetooth dongle. According to this article its AA batteries :

https://cybergibbons.com/uncategorized/arduino-misconceptions-6-a-9v-battery-is-a-good-power-source/

Gusss: I was wondering if there was a simple way of just plugging in a USB Bluetooth dongle to replace the USB cable

Once you have ensured the dongle is OK for simple data connection in SPP protocol, you might find you can do this by using a USB host shield. When you get that sorted, it likely to dawn on you that paying $3-50 for an HC-05 was a pretty good idea. A bluetooth 4 module like the HM-10 is clearly a better choice when using battery power, and they don't cost much more than an HC-05 these days.

whats the longest lasting battery power option (and smallest physical space) ?

Since the staying power of a battery is more or less commensurate with its volume, only you can make that value judgement, particulalrly since are disinclined to mention time, but, if you are serious about using battery power, you probably won't be using a Uno anyway, and quite likely not an HC-05 either. The article you quote doesn't say AAs are best, it just says they are a better choice than a 9v PP3, which is actually true, and then goes off on a fairytale about the virtues of a step up module that would be barely adequate to drive a Uno.

You might find a pair of 18650s a fair place to start, and use them with a decent 5v regulator. And then swap out the Uno for something smaller, like a ProMini or something.

Gusss: 1. Is there a way of just plugging in a USB Bluetooth dongle into an arduino uno to replace the USB cable to get data from the arduino into the PC ?

The simple answer is NO. A USB dongle is designed to plug into a USB host and an Uno is also designed to plug into a usb host.

You need a bluetooth module such as a HC-05 - but I believe they won't work with Apple Macs and I can't remember which type of Bluetooth module is needed for working with a MAC.

...R

Gusss: What sort of power consumption might I be looking at and whats the longest lasting battery power option (and smallest physical space) ?

Did you measure the actual current consumption ?

A real figure is going to be a lot better than everyones guesses.