[SOLVED] Stacking Hats

[kohnworkshop]

Hi Everyone,
I’m using a pi5 with a Raspberry M2 hat.
I also have a Raspberry Dac Pro.
They each work separately, but if I try and stack them the pi does not start (well as best I can tell).
I do not yet know how to access the Pi through the command line.
Do you know if I can stack hats, and those two in particular?

Thanks.

[Tim Curtis]

The symptom suggests the M2 HAT is using one or more header pins the DAC HAT also needs. If thats the case it's prolly one of the 5V power pins but I'm not sure why a an M2 PCIe board needs power since IIRC the Pi5 PCIe bus already supplies 5V, 1A or in watts 5W.

In any case what I use is an NVMe base board that only gets power from the PCIe bus.

- Pimoroni NVMEe base
https://shop.pimoroni.com/products/nvme-...9587178579
- Crucial CT1000P3SSD8, a 1TB NVMe PCIe Gen3 SSD (3W max)
https://www.crucial.com/ssd/p3/CT1000P3SSD8

[kohnworkshop]

The symptom suggests the M2 HAT is using one or more header pins the DAC HAT also needs. If thats the case it's prolly one of the 5V power pins but I'm not sure why a an M2 PCIe board needs power since IIRC the Pi5 PCIe bus already supplies 5V, 1A or in watts 5W.

In any case what I use is an NVMe base board that only gets power from the PCIe bus.

- Pimoroni NVMEe base
https://shop.pimoroni.com/products/nvme-...9587178579
- Crucial CT1000P3SSD8, a 1TB NVMe PCIe Gen3 SSD (3W max)
https://www.crucial.com/ssd/p3/CT1000P3SSD8

Thanks Tim for so much for your answer.
It also seems that both hats no longer work, and the pi5 turns on but I cannot log into the moode interface or find it on the network.
I tried redoing the SD card setup but no difference.
So this was sadly an expensive trial. Bummer.
But I haven’t been able to find anything about NOT stacking hats.
Curious if there’s a resource I can reach out to at least understand what went wrong. Maybe at Raspberry?
Thoughts welcome.
And thanks for the Moode server software which is great.
Daniel.

[TheOldPresbyope]

The symptom suggests the M2 HAT is using one or more header pins the DAC HAT also needs. If thats the case it's prolly one of the 5V power pins but I'm not sure why a an M2 PCIe board needs power since IIRC the Pi5 PCIe bus already supplies 5V, 1A or in watts 5W.

In any case what I use is an NVMe base board that only gets power from the PCIe bus.

- Pimoroni NVMEe base
https://shop.pimoroni.com/products/nvme-...9587178579
- Crucial CT1000P3SSD8, a 1TB NVMe PCIe Gen3 SSD (3W max)
https://www.crucial.com/ssd/p3/CT1000P3SSD8

Thanks Tim for so much for your answer.
It also seems that both hats no longer work, and the pi5 turns on but I cannot log into the moode interface or find it on the network.
I tried redoing the SD card setup but no difference.
So this was sadly an expensive trial. Bummer.
But I haven’t been able to find anything about NOT stacking hats.
Curious if there’s a resource I can reach out to at least understand what went wrong. Maybe at Raspberry?
Thoughts welcome.
And thanks for the Moode server software which is great.
Daniel.

Probably your best bet is to ask about stacking hats on the PasberryPi Forum. 

Regards,
Kent

[mgarman40]

Hi kohnworkshop,

I'm using this hat for nvme m2 from Waveshare:
https://www.waveshare.com/pcie-to-m.2-hat-plus.htm

My stack is Pi 5, m2 hat (with 2tb 2230 ssd) and then Allo Digione hat in this case:
https://kksb-cases.com/products/kksb-ras...and-cooler
As you can see the pins can go through to provide for the next hat in the stack. Besides I think the m2 hat is taking power only from the ribbon cable.
Also I had to buy a box of mixed sizes stanoffs (size 2.5) to accommodate the stack in the case.

The other concern can be that your m2 and dac hats are using more power than your Power Supply can handle. In my case I'm using Raspberry Pi 5 Power Supply (Official) USB-C PD 5.1V 27W. It's providing enough juice to power the lot.

Hope this helps
Cheers

[kohnworkshop]

Hi kohnworkshop,

I'm using this hat for nvme m2 from Waveshare:
https://www.waveshare.com/pcie-to-m.2-hat-plus.htm

My stack is Pi 5, m2 hat (with 2tb 2230 ssd) and then Allo Digione hat in this case:
https://kksb-cases.com/products/kksb-ras...and-cooler
As you can see the pins can go through to provide for the next hat in the stack. Besides I think the m2 hat is taking power only from the ribbon cable.
Also I had to buy a box of mixed sizes stanoffs (size 2.5) to accommodate the stack in the case.

The other concern can be that your m2 and dac hats are using more power than your Power Supply can handle. In my case I'm using Raspberry Pi 5 Power Supply (Official) USB-C PD 5.1V 27W. It's providing enough juice to power the lot.

Hope this helps
Cheers

Thanks mgarman
I hadn’t thought of the power supply issue.
Hoping to meet with a friend tomorrow who can help me troubleshoot.
Daniel.

[mgarman40]

You are welcome.
mg

[kohnworkshop]

Thank you all for your replies.
It’s like the joke.
"OK. Is your computer plugged into the wall?”

It turns out it was …
the power supply.

Once I tried it again with a proper power source, it took a while to restart, but eventually came back online, alone, with M2, and then with M2+ DAC.
So it works at least in that order.

My friend and I were both glad the answer was this simple.