Outputting near max power during setup phase

General Discussion
1

Hi there, this is my first post as a member so please be patient.

I’m writing python test code to control a Lime-mini with a Raspberry Pi. The code in question is just meant to hold the lime mini at a specific frequency and power for a short time to better understand how the Mini is controlled and to calibrate the power measurement devices used in my final product.

However, while setting up the mini in the first section of the script, the device outputs maximum power for the given frequency( ~-10.5 dBm @ 2.45GHz ) for around 2.5 seconds before the devices recognizes my coded power and adjusts down to it. I’m not sure if -10.5 dBm is actually max power at that frequency, but it is much higher than what I’m telling it to output.

I can control the power level with code after that point, but I can not preempt the max power event and it may be the culprit behind some amplifier blow-outs I’ve had.

Before I share any code, I just wanted to ask if any of you had encountered this before and know the fix off the top of your head, whether this is normal behavior, or if its an obvious symptom of a failed device.

Thanks for reading, I’m sure the geniuses out there can help me.

2

Hi @bnwallace,

You are not alone :slight_smile: Which version of the LimeSuite are you using ? Are you using SoapySDR or direct c++ coding ?
I saw in the recent git commit that they have probably fix something related to a «calibration» leak. Perhaps you can give it a try … (that’s on my todo list, but I lack of time).

Best regards,

3

Thanks for the input. I actually inelegantly fixed it by setting the gain to 0 during the instantiation portion and now the power spike is only a fraction of a second, most likely occurring with the change over in gain. I think I’ll just live with this solution for the time being.