Dear Community,
I would like to know how much power is needed in terms of watt for a fully functional Lime SDR mini (V 1.3) board while its transmitting signal in full power? basically i am running SRSLTE with RPi 4 with a lime sdr mini board, just after running the software for 5 minutes the signal connection is lost. I believe this is because of power issue as i tried to run srslte with same limesdr board in intel core i5, where the signal is stable.in case of the pi is not being able supply much power.
So, I would highly appreciate your assistance on how much power a fully functional lime mini board needs and also how much is the limit of current and voltage a lime mini board can tolerate?
Regards
Hi Rozana
I have been using LimeSDR Minis (hardware versions 1.1, 1.2 and 1.3) with Raspberry Pi 3s and Raspberry Pi 4s for a few years now.
They draw about 450 mA on transmit and need the voltage at their input to stay above 4.8v for correct operation. A good quality USB cable is essential avoid voltage drop. Also make sure that you have 5.2v applied to the Raspberry PI - this gives you more margin.
To check what is happening, monitor the voltage on the VCC5P0 terminal on the edge of the LimeSDR Mini with both an oscilloscope and a DMM.
Regards
Dave
3 Likes
Hi Dave,
Thank you so much for your valuable information.I really appreciate your help! 
Best regards,
Rozana
Hi Rozana,
I can see you are running srsLTE with limeSDR mini. I’m playing with srsRAN from last couple of weeks using LimeSDR-mini as both enb and ue.
For me the connection is very very unstable. I tried everything with low n_prb, gain, different earfcn as per the documentation. Every single time after successful attach, it work perfectly for 2/3 minutes and then connectivity lost between enb and ue (same for cots-ue). Subsequent reattach request also failed after that and I had to restart the enb/ue app once again.
Just wondering have you noticed this behavior in your setup using limeSDR mini with stable power supply?
Your problem may also be because of heat. With the LimeSDR USB I have to put it next to a fan, else the transmissions don’t work well.
1 Like
Hi Phoenix,
In my case while I run the eNB on my pc the setup is quite stable.can run quite long period but the problem arises while running it on raspberry pi.you may try with
tx_gain = 80
rx_gain = 40
This power worked well for me.but please make sure that you are providing enough power to your PC and lime mini,also keep any cooler or fan near by while working.i don’t think the earfcn value is going to affect the connection.try to run the eNB with 25 and 50 physical resource block.
Best wishes!
2 Likes
