20160119_191023

So I few weeks ago I received a LeMaker Guitar board that I won on a contest. I got really happy about that and they sent by DHL that made everything went really fast.

As usual, in Brazil the tax everything including prizes and samples, so I got R$90 of taxes over the board. I won’t complain much about it, because it was cheap and expected.

So after some time (sorry for the long time, I got really busy 🙁 ) I managed to write this review about this board!

So talking about the board specs. This is a QuadCore ARM Cortex A9 with 1GB of RAM (a 2GB version is also available according to LeMaker).
<br /> root@lemaker:~# cat /proc/cpuinfo<br /> Processor : ARMv7 Processor rev 1 (v7l)<br /> processor : 0<br /> model name : ARMv7 Processor rev 1 (v7l)<br /> BogoMIPS : 405.50<br /> Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3 tls<br /> CPU implementer : 0x41<br /> CPU architecture: 7<br /> CPU variant : 0x4<br /> CPU part : 0xc09<br /> CPU revision : 1

processor : 1
model name : ARMv7 Processor rev 1 (v7l)
BogoMIPS : 407.96
Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3 tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x4
CPU part : 0xc09
CPU revision : 1

processor : 2
model name : ARMv7 Processor rev 1 (v7l)
BogoMIPS : 407.96
Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3 tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x4
CPU part : 0xc09
CPU revision : 1

processor : 3
model name : ARMv7 Processor rev 1 (v7l)
BogoMIPS : 407.96
Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3 tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x4
CPU part : 0xc09
CPU revision : 1

Hardware : gs705a
Revision : 0000
Serial : 080f4635510a10bf

I’m also using Lemunto for Guitar distro, but it came with Android. I didn’t played much with android to be honest.

<br /> root@lemaker:~# uname -a<br /> Linux lemaker 3.10.37 #2 SMP PREEMPT Sat Jan 16 14:33:53 CST 2016 armv7l armv7l armv7l GNU/Linux<br />

The Lemunto can use Oficial Ubuntu ports (that as I remember is provided by Linaro) and that is really good because we can have most packages we need. For example I wanted rtl-sdr to starting using it as a station:

 

<br /> root@lemaker:~# apt-get install rtl-sdr<br /> Reading package lists... Done<br /> Building dependency tree<br /> Reading state information... Done<br /> The following extra packages will be installed:<br /> librtlsdr0<br /> The following NEW packages will be installed:<br /> librtlsdr0 rtl-sdr<br /> 0 upgraded, 2 newly installed, 0 to remove and 132 not upgraded.<br /> Need to get 0 B/76.1 kB of archives.<br /> After this operation, 293 kB of additional disk space will be used.<br /> Do you want to continue? [Y/n] y<br /> Selecting previously unselected package librtlsdr0:armhf.<br /> (Reading database ... 78752 files and directories currently installed.)<br /> Preparing to unpack .../librtlsdr0_0.5.3-3_armhf.deb ...<br /> Unpacking librtlsdr0:armhf (0.5.3-3) ...<br /> Selecting previously unselected package rtl-sdr.<br /> Preparing to unpack .../rtl-sdr_0.5.3-3_armhf.deb ...<br /> Unpacking rtl-sdr (0.5.3-3) ...<br /> Processing triggers for man-db (2.7.0.2-5) ...<br /> Setting up librtlsdr0:armhf (0.5.3-3) ...<br /> Setting up rtl-sdr (0.5.3-3) ...<br /> Processing triggers for libc-bin (2.21-0ubuntu4) ...<br />

20160121_190716

Also I wanted to test a 7” HDMI TouchScreen from Chalk-Elec that I have here on my desk. It usually works with any HDMI device, but I had some problems with Chromecast for example. But it works really fine for my LeMaker Guitar!

 

About the performance as using it as a RTL-SDR Spectrum Server, it was perfect. I could even sample 2.56Msps through its 72.2Mbps wireless network (sadly not 5Ghz or AC network) without loss. But be noticed that I have about full signal here:<br /> root@lemaker:~# iwconfig<br /> wlan0 IEEE 802.11bgn ESSID:"TVS" Nickname:"<WIFI@REALTEK>"<br /> Mode:Managed Frequency:2.457 GHz Access Point: 70:62:B8:6B:A6:3C<br /> Bit Rate:72.2 Mb/s Sensitivity:0/0<br /> Retry:off RTS thr:off Fragment thr:off<br /> Encryption key:****-****-****-****-****-****-****-**** Security mode:open<br /> Power Management:off<br /> Link Quality=97/100 Signal level=-54 dBm Noise level=0 dBm<br /> Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0<br /> Tx excessive retries:0 Invalid misc:0 Missed beacon:0<br />
So it might not be enough to do a full sample rate spectrum server, but if you just want to receive NOAA, or even broadcast NOAA signal using a Spectrum Server, you can make a software do to signal decimation to reduce the sample rate to 80KHz (a decimation of 32) and increase the ADC Resolution.

For now is just that. I expect to put it to work as a SDR Spectrum Station together with my Intel Edison and see which one performs better for receiving / processing NOAA APT Signals, and maybe LRPT signals. I just expected that this board came with a 5GHz / AC Wireless :/