Hardware platform similar to d-link 320 router?

Question

linux

I am engaged in software and ask for advice on hardware.
We have a young project of our software on Linux on intel atom for telemetry.
There was a need to switch to another hardware platform, to make it cheaper than intel atom, more compact.
The first thing that came to mind was the d-link dir-320 router, custom firmware based on Linux, working with usb, serial ports, modems, etc. suits our needs perfectly.
I looked, there is a Broadcom BCM5354 processor, but it’s specifically for routers, as I understand it, it has something for Wifi that we don’t need. We can do something general.
Raspberry Pi is a compact thing, but it's expensive and you don't need hdmi, etc.
Who can advise which processor to choose and the platform scheme in order to get a device on which you can upload Linux, such as dd-wrt, so that you can make usb on the platform for further connection of a 3G modem, for example, and serial 232 ports.
Where to collect - we will find.
Criteria: low cost, availability, stability of the firmware with Linux.

Answer 1

$25 is expensive? It seems to me that you will not find a cheaper board for Linux. You can save money if you switch to cheaper processors, but Linux will not be there, you will have to rewrite the software, and cheap processors rarely have USB.
Unless if you need 1000+ pieces, you can order boards from the Chinese, well, they will cost 17-20 dollars, but how much hemorrhoids ...

Answer 2

Why is the presence of Wi-Fi in the router so annoying? Well, there will be an extra module inside the crystal, cut it off and you will never turn it on if it is not needed.
If it meets all other criteria, then this is a very good option. In addition, these routers are just clouds, the same one that has become popular, the MR3020, which generally costs 800 rubles.

Answer 3

In general, the algorithm is as follows: take any debugging board that can run Linux - on the processor that is easiest to get and which is cheaper - look at which it has already been ported and runs stably. Schematics always go to debugging ones. Googled elementary.
Cross out the superfluous from the schematic - ethernet and other goodies are built into the central processor, usually only a harness outside, such as an ethernet decoupling - so do not look at the fact that the board supports ethernet, a display or something else.
After you breed the board and give it to production.
But. I guarantee you that the production and assembly of these boards will cost you more than buying any ready-made debug boards, including RP. Unless, of course, you plan to produce millions of pieces.