using bare metal embedded system



I am a long-time embedded system designer, but a newbie to embedded cellular connectivity and I need help. I have a client who wants me to develop a product for him to be sold in moderate volumes. The system is an industrial controller and falls under FCC Class A.

He wants:

  1. global coverage (North America, the EU, China, some in Africa);
  2. a protocol that offers some longevity into the future;
  3. the system to be fully encapsulated except for some application-specific connectors;
  4. moderately low cost;
  5. highly reliable (it will be operational 24/7)

I think that items 3, 4 and 5 mean that it will be a custom-designed bare-metal system (no off-the-shelf operating system except perhaps a certified real-time operating system). Items 1 and 2 mean that I should be exploring MVNOs (which is why I am on this site). Items 1 and 2 also make me lean toward LTE Cat M but I am open to any and all advice.

I also need help with the certification process for this system. My understanding is that by using a module that has an FCC modular grant, I reduce the cost and time for certification substantially, but having never done this, I don’t know.

So my questions:

  1. Does a bare-metal system make sense for this? Reliability and robustness are key, and I have experience successfully designing many such systems bare-metal systems and creating reliable software for them. I don’t foresee a problem in that regard.

  2. What are the issues that I face in both hardware and software for integrating a suitable module into my system? I have experience integrating XBee modules, peripheral devices for which a protocol is required, using SPI, I2C, UARTs and similar protocols, etc.

  3. What are my certification requirements to be able to deploy the product world wide?

  4. How can I reduce the certification requirements as much as possible?

I would welcome any help that anyone can offer me.

Best regards,



Howdy Peter,
I am working on a similar project I believe.
Perhaps we should speak directly, my email is
We can summarize and post back to this thread after we speak.

My device is based on debian unix, requires no updates and is bulletproof.
Talks to the world over Nova cellular Modem
The Hologram system uses different modem styles to fit your needs.
Can send and receive SMS messages which can be used to run any command.
All of the coding is simple unix shell commands, python, ruby or whatever your poison.
We use ftp macros and wget to download new firmware(software) on a schedule from cron.
We have 15 devices out in the world in our test phase which we rolled out last week.
We are very happy with the results so far.
Our production program will start with 1000 devices and will be driven by demand.
We pay $10.00 for the computer module and our hardware is about $300.00 total per unit in our case.
If you have looked at the Cellular modem like the Nova for example, data costs are reasonable.
We have gone through certification for emissions and I can look up those costs.
Feel free to send me an email -


Hey Gents,

Haven’t seen an posts here so wanted to chime in and see if there is anything I can help with from the Hologram side of things.



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