HW improvement wishlist

[paigeadelethompson]

• trackball should have a tactile button underneath it and kinda depends on it for structural support (the trackball travel is greater than it would be if it met with the resistance of a tactile button and doesn’t roll as accurately the more its pushed down
• something for time keeping would be nice (NTP isn’t always reliable: https://www.pishop.us/product/ds3231-real-time-clock-module-for-raspberry-pi/)
• A tpm would be cool but would depend on the soc:
  Raspberry Pi 4 TrustZone Support OP-TEE/optee_os#3205
  https://developer.arm.com/documentation/100690/0201/Security-requirements-addressed-by-TrustZone-technology-for-Armv8-M

There are some higher end compute modules on the market but whether or not they could be made to work (depends on dtb and availability, documentation, pin compatibility) but they might have better options, like NXP: https://www.compulab.com/products/computer-on-modules/cl-som-imx8plus-nxp-i-mx-8m-plus-system-on-module-computer/

[paigeadelethompson]

NXP UCM SoM documents https://www.compulab.com/products/computer-on-modules/ucm-pin2pin-system-on-module-family/

[paigeadelethompson]

Various system on modules info https://portwell.com/products/sodimm-som.php

[paigeadelethompson]

Some of these SoMs may require something like yaffs2/units if they don’t have built in wear leveling (bare mtds, possibly some emmc?) tldr slight change to partitioning / imaging

[paigeadelethompson]

Haven’t figured out yet if the CPI 3.14 connector is pin compatible with anything https://forum.clockworkpi.com/t/rpi-cm4-adapter-for-devterm-cpi-v3-14/8663

[paigeadelethompson]

https://www.reddit.com/r/RASPBERRY_PI_PROJECTS/comments/p2uwh3/what_is_the_connector_on_cm4_called/

[paigeadelethompson]

NXP uses Hirose Electric Co., Ltd. connectors in some of its products, including the NXP HoverGames drone development kit and the i.MX53 Quick Start-R Board:

https://ronetix.at/product/i-mx8mp-compact-cm-cpu-module-som-with-nxp-i-mx8m-plus/ This one has three..

CPI has two but two of them are at least 100p:

DF40C-100DS-0.4v
DF40HC(3.0)-100DS-0.4v

https://ronetix.at/product/i-mx8mn-compact-cm-cpu-module-som-with-nxp-i-mx8m-nano/ This one has two

[paigeadelethompson]

Imx8 nano compact datasheet & pinout http://download.ronetix.at/boards/doc/i.MX8MN-COMPACT-CM/i.MX8MN-COMPACT-CM_Datasheet.pdf

tldr it does not appear to be pin compatible with the cm4
https://datasheets.raspberrypi.com/cm4/cm4-datasheet.pdf

But it needs an adapter anyway to work with the uconsole and the cad files for the adapter I think these are it but need to check https://github.com/antmicro/raspberry-pi-cm4-csi-adapter/blob/master/rpi-cm4-csi-adapter.kicad_pcb

Making a carrier board for the cm4: https://www.digikey.com/en/maker/projects/creating-a-raspberry-pi-compute-module-4-cm4-carrier-board-in-kicad/7812da347e5e409aa28d59ea2aaea490

kicad footprints for an sodimm:
https://github.com/Wallbraker/SODIMM

*Dimensions / specs in the imx8 data sheet

Uconsole sodimm pinout https://github.com/clockworkpi/uConsole/blob/master/clockwork_Mainboard_V3.14_V5_Schematic.pdf

I’ll try to piece together an adapter if possible and send a vervet to pcbway or something, the horse connectors are surface mount and I don’t think they’ll take hot air without melting so it’d probably have to be put in an oven, I’ve heard some of the pcb quickie sites will place some or all parts for a small additional cost (we shall see)

[paigeadelethompson]

https://ronetix.at/product/i-mx8mp-compact-cm-cpu-module-som-with-nxp-i-mx8m-plus/ This one has three..

this guy has a lot of good info about compute modules:
https://github.com/geerlingguy/sbc-reviews