# LimeSDR-mini FIR Setting

**URL:** <https://discourse.myriadrf.org/t/limesdr-mini-fir-setting/7446>\
**Category:** Lime Suite\
**Created:** [6 December 2021 16:36 UTC](https://discourse.myriadrf.org/t/limesdr-mini-fir-setting/7446 "2021-12-06T16:36:43Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Nelson](https://avatars.discourse-cdn.com/v4/letter/n/dec6dc/32.png) [@Nelson](https://discourse.myriadrf.org/u/Nelson)\
**Post date:** [6 December 2021 16:36 UTC](https://discourse.myriadrf.org/t/limesdr-mini-fir-setting/7446/1 "2021-12-06T16:36:43Z")

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HI.

I use C++ to control the LimeSDR. Now I am trying to set a FIR for my LimeSDR

```
	LMS_SetLPFBW(device, LMS_CH_TX, 0, 10e6);
	LMS_SetLPFBW(device, LMS_CH_RX, 0, 1.5e6);

	LMS_SetLPF(device, LMS_CH_TX, 0, true);
	LMS_SetLPF(device, LMS_CH_RX, 0, true);

	LMS_SetGFIR(device, LMS_CH_TX, 0, LMS_GFIR3, true);
	LMS_SetGFIR(device, LMS_CH_RX, 0, LMS_GFIR3, true);
   

	LMS_SetGFIRLPF(device, LMS_CH_TX, 0, true, 10e6);
	LMS_SetGFIRLPF(device, LMS_CH_RX, 0, true, 1.5e6);
   
    LMS_Calibrate(device, LMS_CH_TX, 0, 2.5e6, 0);
    LMS_Calibrate(device, LMS_CH_RX, 0, 2.5e6, 0);

```

I am not sure this is right or not.  
And GFIRLPF always show that GFIR LPF connect be set to the requested bandwidth.  
What I want to do is using FIR to decrease the noise from the Antenna. The Sensor I use is a bit sensitivity, The result is good with cable, but when I add antenna into the system, the I cannot get the result. So, I guess it’s the noise problems.

Also, I cannot find the LimeSDR C++ API document, I have no idea the value that can set for LPF.

Anyone can help me? Thank you very much.

Also, Where is thee DC corrector on C++ library?

---

<div class="post-metadata">

**Author:** ![yt7pwr](https://avatars.discourse-cdn.com/v4/letter/y/ecd19e/32.png) [@yt7pwr](https://discourse.myriadrf.org/u/yt7pwr)\
**Post date:** [6 December 2021 19:12 UTC](https://discourse.myriadrf.org/t/limesdr-mini-fir-setting/7446/2 "2021-12-06T19:12:20Z")

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**GFIR** : set only LMS\_SetGFIRLPF with BW=0 to disable GFIR or BW=0-100% of sample rate for auto enable with desired BW (for example: 0.1\*1e6 is 100KHz GFIR bandwidth)  
**Calibration** : LMS\_Calibrate minimum BW is 5e6 (5MHz), if you set less Limesuite dll will auto correct  
**API exported function list** (with detailed explanation):

> <https://github.com/myriadrf/LimeSuite/blob/master/src/lime/LimeSuite.h>

**Parameters list:**

> <https://github.com/myriadrf/LimeSuite/blob/a45e482dad28508d8787e0fdc5168d45ac877ab5/src/lime/LMS7002M_parameters.h>

(when you hover with mouse over controls in LimeSuiteGUI hint messages are from this file)