Integrate RTL-SDR into Android phone

[idoit]

Hi all,

I would like to integrate RTL-SDR inside the phone instead of having to carry the USB dongle all the time. Has anyone done a similar project?

Is it really power consuming, in that it eats battery juice quickly?

[rtlsdrblog]

I haven't seen any project doing what you describe yet. The RTL-SDR uses about 250 mA of current while active so it can be quite draining on the battery. This is why most Android users use an OTG cable with a power port, so that they can power the device from a large external battery or wall powered supply.

[idoit]

I see rtlsdrblog. So it's way more battery hungry that the internal FM radio some smartphones have, right?

Three questions in this regard:
1. How much is the power consumption of a regular FM chip inside a smartphone approximately?
2. What is the most efficient RTL-SDR dongle?
3. What is the most comprehensive and powerful RTL-SDR dongle?

[rtlsdrblog]

1) Not sure but I would guess not that much. You could check with a battery monitoring app.

2) The E4000 dongles only use about 150 mA.

3) There's not much difference between dongles. I prefer the R820T2's for general use since they have the best performance to price ratio, and are usually better than the E4000.

Also, one other factor that affects your power usage will be the fact that when using the RTL-SDR, the CPU usage will probably be quite high, causing extra drain.

[osramrtlsdr]

Nice idea. I need double OTG ports on android phones but none of the phones I have seen has that.
It allows one for the dongle inside or outside the phone and another one for the external battery or the power charger.

[AECRADIO]

With the current trend to cram as much as possible into smaller, and more restrictive form factors, getting a current RTL-SDR device to fit, will become a
major undertaking. One also needs to address the current dem, ands of the device as well, but so far, little has been discussed concerning heat generation caused from an operating 2832/r82T2 chipset. The heat expended for such miniscule devices is tremendous (my viewpoint), soI doubt you would have a
phone that survived due to the generated heat building up internally during operation of the integrated device.

Curent draw as it stands now, really is a major drawback to including these chipsets inside any handset.
Not to mention the potential for device interference during operation. Sum and difference frequencies, harmonics, image frequencies and even IMD products are possible. Shielding would become the third largest hurdle to jump over after current demands and heat generation.
Not worth the trouble to make this a workable project in my humble opinion.