| ▲ | micw a day ago |
| Does anyone know if it's a good idea to base a product on Pi CM4/5 (or has experience with this)? I wonder how the availability any price in large quantities is (like 10k per year) and how reliable the connector is in comparison to a soldered SOM. |
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| ▲ | davidhyde a day ago | parent | next [-] |
| 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. |
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| ▲ | the__alchemist a day ago | parent | next [-] | | 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. | |
| ▲ | jacobmarble a day ago | parent | prev | next [-] | | 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. | | |
| ▲ | davidhyde 15 hours ago | parent [-] | | 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 |
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| ▲ | Joel_Mckay a day ago | parent | prev [-] | | 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, =) |
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| ▲ | nsnxjxnd a day ago | parent | prev | next [-] |
| While we have never used the compute module in large quantities, we have used it numerous times for small batches with 1-2k/month and had no issue there If you plan on using it for small series of <10k/a I wouldn't worry too much |
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| ▲ | pyb a day ago | parent | prev | next [-] |
| Even if it were reliably available in such quantities, I'm not sure Pi's pricing would make sense in the context of any mass produced product. |
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| ▲ | awjlogan a day ago | parent | next [-] | | They are available in that quantity. They do make sense up to around that number, although the around 1K is the sweet spot. Laying out and certifying a high speed design (not just a noddy A9 with DDR2) is expensive and it's all NRE cost. The cost of the components for the CM is driven down by the combined volume significantly - if you want to buy 1-10K of those by yourself, you will pay a premium over what RasPi gets them for. You might not need a full 6/8 layer board for the whole product as well. As important, the software support is great as it's just a standard RasPi - you don't have to support your own custom image. | | | |
| ▲ | detaro a day ago | parent | prev | next [-] | | They are far from the most expensive SOMs on the market. | |
| ▲ | pyb a day ago | parent | prev | next [-] | | There are apparently products based on the CM (Ableton Move?), not sure how they sell these at a profit. | | |
| ▲ | hobofan a day ago | parent | next [-] | | The Formlabs Form 4 uses a CM AFAIK and at a 4-5k price point it's not hard to see how they sell them at a profit. | |
| ▲ | Joel_Mckay a day ago | parent | prev [-] | | Design for Manufacturability paradigms sometimes generate odd choices that only make sense in certain use-cases. When scaling up to over 50k pcs/month the incremental costs do get ugly fast. However, for many of the same reasons a 3k USD PLC makes sense in many low volume long-tale market applications (i.e. pre-certified and stamped hardware.) Best of luck, =3 |
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| ▲ | eptcyka a day ago | parent | prev | next [-] | | Mass producers do not buy at retail prices. | | |
| ▲ | Joel_Mckay a day ago | parent [-] | | Sometimes we do, but it hits both us and the end customer. Recall the chip shortages... =3 |
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| ▲ | Joel_Mckay a day ago | parent | prev [-] | | Volume pricing on custom commercial Pi SoM are not common, but do happen at the Pi foundation. I have seen 3 or 4 products with these pi+Debian SoMs running network services etc. Getting them to be reliable is a different set of issues with dozens of edge cases, but its the same with every other vendor. Best regards =3 |
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| ▲ | Joel_Mckay a day ago | parent | prev | next [-] |
| In general, the pi SoM usually offer 8 to 12 year availability maps, and haven't pulled price ballooning after launch. If you are producing less than 1k pcs a month, than it certainly makes sense for smaller design runs. That being said, it is probably safer to eat the cost on the standard 0.1" ribbon cable header form-factor if you plan to run the line for a few years. The compute-modules have a tendency to change, and the micro-contact headers could be a failure point in some situations. Also, hardening the Pi design to be more reliable takes extensive testing, and experience. Compared to other SoM manufacturers the Raspberry Pi foundation has a good reputation in both the open source community, and commercial roles. The pi4/5 FCC modular pre-compliance also saves around 11k USD when you go for lab testing. Also, pushing pi SoM production volumes higher means lower unit costs for everyone, and a double win is always nice. If you don't need the gpio, than a mini PC form factor may offer more value. There is also the Kria KR260 kits around, but it will not offer anywhere near the software/kernel ecosystem support of the pi community. Best of luck, =3 |
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| ▲ | a day ago | parent | prev | next [-] |
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| ▲ | sitzkrieg 18 hours ago | parent | prev | next [-] |
| i have. avoid pis in retail products period unless you work at broadcom or want to sell a subpar device |
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| ▲ | cess11 a day ago | parent | prev [-] |
| Probably a better idea to go for the ROCK-chip TFA is using in the benchmarks or something similar. |
