Nokia EKSOS N20 DIY carrying case » History » Version 2
laforge, 08/27/2023 11:38 AM
1 | 1 | laforge | h1. Nokia EKSOS N20 DIY carrying case |
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3 | In preparation of the first hacker event where we wanted to offer ISDN Uk0 service (see [[ISDN_at_CCC_Camp_2023]]) we wanted to build portable, self-contained and ruggedized systems from the Nokia EKSOS. |
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5 | The systems should contain |
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6 | * EKSOS N20 shelf with mandatory NCU and some subscriber line cards |
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7 | * a number of subscriber ports broken out to RJ45 connectors |
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8 | * a 48V power supply |
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9 | * an [[Osmocom_icE1usb]] plus an embedded Linux board to run TDMoIP for the V5 back-haul |
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10 | ** should have at least two Ethernet ports so we can also back-haul the Q3 management interface to a remote location |
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11 | * some fans for active cooling as it is getting rather hot in the sun outdoor on a camp |
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12 | * ruggedized enclosure to make sure the equipment survives transportation unharmed |
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14 | h2. Enclosure |
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16 | h3. Fans / Cooling |
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18 | h2. Power Supplies |
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20 | h2. Subscriber port break-out |
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22 | h2. icE1usb + Linux SBC |
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24 | Given that we needed multiple Ethernet ports in a Linux SBC with passive cooling, there weren't really all that many options on the market. I went for a *nanopi R5S*, which has 3 ethernet ports. |
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26 | h3. nanoPI R5S 12V DC re-work |
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28 | For some weird reason, the nanoPi R5S *only* supports USB-PD. There is no straight DC supply connector for feeding e.g. 12V to it. Not even an unpopulated header on the circuit board. |
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30 | This meant that it simply wouldn't power up at all if 12V were applied from the 12V mean-well power supply in the unit. Luckily, @tnt and I came up with some hardware re-work to modify the R5S to accept a 12V DC input without any USB-PD signaling: |
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32 | FIXME: Describe the rework |
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34 | h4. Unmodified R5S |
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35 | 2 | laforge | |
36 | !20230809_233333.jpg! |
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38 | h4. R5S with removed resistor |
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40 | !20230809_233308.jpg! |
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42 | h4. R5S with additional pull-up resistor |
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44 | !20230809_233231.jpg! |