#│forum
About the 4 Micro JST connectors on the motherboard
# │forum
d
daboone72
04/09/2023, 9:41 AMThis to discuss about the 4 JST connectors next to each node.
I just learned that they appear to initially be for the Jetson modules as Raspberry Pi CM4s can't do PWM so any fan connected there won't turn on and off by itself.
Will the RC1s be able to control fans connected here?
And now knowing that it is for Jetson Orin you can find fans with the right connector. https://www.waveshare.com/orin-fan-pwm.htm
And you can see it in the docs here J9 Fan connector 4-pin 1.25mm pitch https://developer.nvidia.com/embedded/learn/jetson-agx-orin-devkit-user-guide/developer_kit_layout.html
u
_dhanos_
04/09/2023, 11:56 AMAll active Jetson coolers are using this conenctor
r
rubberduck
04/09/2023, 5:12 PMCan the pins of the connectors be accessed CM4 at all? Would be great to repurpose them for something else...
u
_dhanos_
04/09/2023, 5:53 PMWhich pins do you mean? In the SO-DIMM connector? If yes, they all have a very specific purpose, they're not GPIO
r
rubberduck
04/09/2023, 5:56 PMYes, the SO-DIMM sockets used for PWM on the Jetson modules. Was thinking they might be connected as a GPIO for the CM4.
u
_dhanos_
04/09/2023, 5:57 PMI checked that already. The pins used with the JST connector are not connected to anything on the CM4
t
terarex
04/10/2023, 12:57 AMThe GPIO pins are attached only to node1 (the first CM slot).
d
daboone72
04/10/2023, 9:52 AMAfter seeing this hopefully the Turing Pi guys can integrate the circuit into the CM4 adapter boards. https://thepihut.com/products/pwm-controlled-fan-hat-for-raspberry-pi
u
_dhanos_
04/10/2023, 11:56 AMI already shared this idea with the Team. There's this chip that's on the devboard which support is already added to the RPi OS. Maybe future revision of the adapter board will contain this
t
teslamax
04/10/2023, 5:42 PMAre the specs for the adapter board open? I’m curious if we can expect any third parties to make adapter boards with custom features like an OLED or PWM fan headers if the team choses not to?
u
_dhanos_
04/10/2023, 5:43 PMThey are not. They might be in the future. It's still unclear what might get opened.
t
teslamax
04/10/2023, 5:43 PMThank you!
r
rubberduck
04/10/2023, 7:49 PMYes, I know - but I asking about the "Slot fan" headers next to each SO-DIMM slot 🙂
t
terarex
04/10/2023, 7:54 PMYeah. We' have to look at the Turing Pi V2 board schematic(s) for that info. I don't believe that info will be open sourced. The signals on the compute module connector should match the NVIDIA Jetson Nano (B01)/TX2/Xavier pinmux. That information is available from NVIDIA.
u
_dhanos_
04/10/2023, 8:29 PMI mean I already checked that and asked about it. I thought maybe some GPIO is connected and we could utilize it, but if you look at the adapter board pins, you'll see these for the fan header are not connected - this is what I figured out by looking at the Jetson board documentation and comparing it to the adapter board. So I asked about it and learned that indeed such feature is not implemented for CM4s
So, I asked and proposed to
go the Raspberry Pi CM4 IO Board route and add a small chip, EMC2301 (I2C FAN controller) to the adapter board. As of May 2022 the controller driver is merged into the Raspberry Pi OS, so I'm guessing it'll work more out of the box.The adapter board will need this additional chip to be added somewhere and then connect to these given pins that are routed to the fan header
For now, there are no plans to revise the adapter board
t
terarex
04/10/2023, 8:41 PMYeah. I see the CM4 adapter as somewhat of a transitional tool until RK1 is fully debugged and shipping. I'm certain when the KickStarter plan was being put together, the Turing Machines folks thought that CM4s would be readily available before RK1. It's beginning to look like they'll both be available around the same time. For general-purpose use, the RK1 has significantly better price-performance. We'll see how soon RockChip can advance Linux support.
u
_dhanos_
04/10/2023, 8:43 PMYeah, I have really high hopes for RK1
But I can see another revision of the adapter board for CM4s
Or maybe one for CM5s?
People might choose CM4s for multiple reasons still, too
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