12VDC mini PC / LCD / SDR

[RobDLG]

I'd become accustomed to buying refurbished business-class PCs from Dell, then a couple of years ago, I read about inexpensive mini PCs here in the RR Forums.

I subsequently ordered two "BMAX" mini PCs from Amazon for about $90 each. My initial assessment was that they clearly didn't have a lot of processing power, but they had an intriguing attribute: a 12VDC power supply. This suggested they could be operated using a number of readily-available portable power sources, including battery, solar, and automotive systems.

Last week, I finally got around to testing 12V battery power:



Here, a Westinghouse iGen200s is providing 12VDC power to the BMAX mini PC and a 7" 1024x600 LCD. The mini PC is about 4.75" on each side, and its four USB ports are powering a GPS receiver, mini keyboard, and, most importantly, two RTL-SDR Blog V4 dongles.

(The large USB hub is only for debugging. Also, I originally meant to use a touchscreen, but neither the on-screen keyboard nor full mouse emulation is working, yet. The mini PC has built-in Bluetooth, but it has been unreliable. Too bad, because that could free up a USB port.)

The mini PC has a two-core Celeron processor at 2GHz, 8G memory, and is running Fedora 44 with trunk-recorder. In the picture, the two SDRs are tracking and recording all calls on the A Mountain site of NM-DTRS. The power consumption reported by the iGen200s typically varies from 6W to 12W, depending on processor load. (For comparison, an SDS200 is steady at just over 4W.)

The most recent trunk-recorder release, v5.2.1, doesn't actually support Fedora 44, but there is a patch available.

The "htop" program reveals that trunk-recorder with two SDR dongles can push the mini PC to its limit. In particular, the calls to "ffmpeg" consume most of the processing power. This leads me to conclude that one processor core per dongle is a good rule when provisioning SDR. Also, it's notable that only a fraction of the 8G of memory is used.





Eventually, I'd like package the mini PC, LCD, and USB devices in a luggable case, maybe something from Harbor Freight or Tractor Supply Co. My next step, though, will probably be to fit everything in a plastic crate from Dollar Tree, maybe with a small 12V battery.

 

[N9JIG]

I have been a big fan of the original NUC series from Intel, they can often be found rather cheaply these days. There are other current manufacturers of small form factor (SFF) PC's and Thin Clients. Most of these can be used to run Windows 10 and before as well as various Linux distro's. Newer ones can run Windows 11 as well.

I saw a reseller that had a bunch of mini-PC's recovered from Point of Sale (POS) systems that looked fairly similar to yours. They came with some form of a thin Windows OS but were able to have regular Windows 10 installed. A friend used several of these for remote clients in place of Raspberry Pi's, which had become too expensive. 8GB of RAM and a 512MB SSD came with them for about $50 or so each, bring your own OS.

These little gems are great for singular task deployments, like a remote scanner or SDR, home automation etc.

 

[jeepsandradios]

I use the beelink mini PC for most of my remote sites since NUC stopped selling them. Some are 12v as I have DC on site. Been using them for a few years and its a solid platform for my use. The beelink comes with W11 installed so I just power on, go thru basic setup and install my software and done.

 

[sdabbey]

I use the beelink mini PC for most of my remote sites since NUC stopped selling them. Some are 12v as I have DC on site. Been using them for a few years and its a solid platform for my use. The beelink comes with W11 installed so I just power on, go thru basic setup and install my software and done.

FYI, NUCs are still a thing. Asus picked up manufacturing and support when Intel dropped it and are still making new NUC models.

 

[RobDLG]

Correction: The CPU in the BMAX MaxMini B1 Pro is more accurately described as an "N4000", despite the fact that /proc/cpuinfo includes a "Celeron" designation.

processor    : 0
vendor_id    : GenuineIntel
cpu family    : 6
model        : 122
model name    : Intel(R) Celeron(R) N4000 CPU @ 1.10GHz
stepping    : 1
microcode    : 0x2e
cpu MHz        : 2582.218
cache size    : 4096 KB
physical id    : 0
siblings    : 2
core id        : 0
cpu cores    : 2
apicid        : 0
initial apicid    : 0
fpu        : yes
fpu_exception    : yes
cpuid level    : 24
wp        : yes
flags        : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf tsc_known_freq pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg cx16 xtpr pdcm sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave rdrand lahf_lm 3dnowprefetch cpuid_fault cat_l2 pti cdp_l2 ssbd ibrs ibpb stibp ibrs_enhanced tpr_shadow flexpriority ept vpid ept_ad fsgsbase tsc_adjust smep erms mpx rdt_a rdseed smap clflushopt intel_pt sha_ni xsaveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts vnmi umip rdpid md_clear arch_capabilities
vmx flags    : vnmi preemption_timer posted_intr invvpid ept_x_only ept_ad ept_1gb flexpriority apicv tsc_offset vtpr mtf vapic ept vpid unrestricted_guest vapic_reg vid ple shadow_vmcs ept_violation_ve ept_mode_based_exec tsc_scaling
bugs        : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass rfds bhi spectre_v2_user old_microcode
bogomips    : 2188.80
clflush size    : 64
cache_alignment    : 64
address sizes    : 39 bits physical, 48 bits virtual
power management:

 

[RobDLG]

I haven't yet field-tested my "portable SDR", but I did realize the "cyberdeck" potential.

Of course, there are a couple of issues.

1. I have little interest and limited resources for creating a (requisite?) "steampunk" enclosure for the LCD/PC/SDRs.
2. A built-in 12V battery would be a challenge, especially since I wouldn't plug it in without a regulator (or "stabilizer" as kids call it nowadays).

Nevertheless, Cyberdecks are evidently a thing.

This Mini Cyberdeck Is Packed with Interesting Hardware

When TechAirSpace ordered parts for this mini cyberdeck, it seems that they slipped and accidentally ordered everything.

www.hackster.io