Hacker News Reader

Comment by davidhyde | Hacker News Reader

As someone who spent many months designing a product around CM4 and then waiting for more than 2 years for modules to arrive over the parts shortage era (eta kept being pushed out by the distributor) I will never put myself in that position ever again. The solution I have found was to skill up and learn how to do hardware design myself. At that point there are many more options. Understandably that's not ideal for a lot of people.

View on HN

Unfortunately, chips EOL all the time, charge pin-outs, and the temptation to in-house an integrated SoM solution may add hundreds of thousands to the cost. If you are not moving >3m chips a quarter, than you are still vulnerable.

We also had to violate the Design for Manufacturability guidelines to adapt to the shortages and part skelpers hitting JIT lines. Even today, we incur a questionable 12 USD labor cost on every product to ensure a generic carrier PCB drop-in population option is always available (0.1" pins 1980's style).

Training slide deck: "Rule #21: No unicorn parts, and no excuses"

We dodged the CM4 choice luckily due to my concerns, but still were tagged by a proprietary missing RF module needed for legacy system interoperability. The vendors lied about inventory levels, and kept the order tied up for years before the spools arrived.

Best of luck, =)

I see your point, and in most cases I would agree with you; this was an unusual time; you would have had the same problem using STM32s, etc.

Can you highlight the resources that you used to level up this way? I can design my own microcontroller boards, but the complexity of SoCs and required peripherals seems too much for this part-timer.

Admittedly I ended up building a board with a microcontroller rather than a microprocessor because I could interface with the modem over spi too. However, this YouTube channel was great to work through:

http://www.youtube.com/@PhilsLab

It has some high speed stuff with ddr memory, fpga’s gigabit Ethernet and usb3 too so I’m pretty sure you could use the same concepts to build a board with a microprocessor on it. Proper grounding, emi, impedance control and length matching are well explained. I think he has some more advanced courses via his website too.

Additionally, this was an ah-ha moment video for me: https://www.youtube.com/live/ySuUZEjARPY?feature=shared

Reply on news.ycombinator.com