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).

root@lemaker:~# cat /proc/cpuinfo
Processor : ARMv7 Processor rev 1 (v7l)
processor : 0
model name : ARMv7 Processor rev 1 (v7l)
BogoMIPS : 405.50
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 : 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.


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

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:

 


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

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:
root@lemaker:~# iwconfig
wlan0 IEEE 802.11bgn ESSID:"TVS" Nickname:"<WIFI@REALTEK>"
Mode:Managed Frequency:2.457 GHz Access Point: 70:62:B8:6B:A6:3C
Bit Rate:72.2 Mb/s Sensitivity:0/0
Retry:off RTS thr:off Fragment thr:off
Encryption key:****-****-****-****-****-****-****-**** Security mode:open
Power Management:off
Link Quality=97/100 Signal level=-54 dBm Noise level=0 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

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 :/