Power budget of LimeSDR Mini 2.4 — max current drawn

Projects LimeSDR
1

Hello,

what is the power budgeting of the LimeSDR Mini 2.4? that is, what is the maximum power (in amps at 5V) it would consume when operated at its maximum potential.

I am asking this because I want to know if I can drive the Mini 2.4 to its maximum potential by connecting it to the Raspberry Pi 4B’s USB 3.0 connector. The Raspberry Pi docs say that a maximum of 1.2 A at 5 V is available, shared by all the USB ports.

Could someone please provide information on this, and is there a document that lists the power budgeting?

Thank you.

2

Hi

I did some tests with a Lime Mini V2.2 running typical use cases and the maximum current drain (transmitting at max power on 3.4 GHz) was 470 mA. This is less than the earlier Lime Mini V1.2 which drew 510 mA.

It runs well from a Raspberry Pi 3, 4 or 5, but you need to make sure that the supply volts to the Raspberry Pi are around 5.2v so that the Lime gets at least 5.0v.

Hope that helps

Dave, G8GKQ

3

Thanks! This might be obvious, but you connected the ammeter while the device was powered by a DC power supply, right? Or is there another way, like reading the current drain on RPi or something?

4

As I recall (it was over 2 years ago), I broke into the 5v wire in a USB lead and used an external power supply and test meter so that I could compensate for the voltage drop across the meter.

There is no way to measure the current drain from USB on a RPi.

Dave, G8GKQ

5

Ok got it, thanks a lot for the info