Nokia EKSOS N20 DIY carrying case » History » Version 3
laforge, 08/27/2023 11:43 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 | 3 | laforge | The enclosure is made of wooden panels. |
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| 18 | h3. wood corpus |
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| 20 | h4. Assembled enclousre body |
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| 22 | !20230801_203832.jpg! |
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| 24 | h4. Milling left and right sides to accomodate screw heads |
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| 26 | Unfortunately the EKSOS shelf mounting flanges contains a number of screw heads and other protrusions, which require the side panels to be milled |
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| 28 | !20230801_203546.jpg! |
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| 30 | h4. Bottom side / gliders |
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| 32 | !20230801_203821.jpg! |
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| 34 | 1 | laforge | h3. Fans / Cooling |
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| 36 | h2. Power Supplies |
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| 38 | h2. Subscriber port break-out |
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| 40 | h2. icE1usb + Linux SBC |
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| 42 | 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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| 44 | h3. nanoPI R5S 12V DC re-work |
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| 46 | 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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| 48 | 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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| 50 | FIXME: Describe the rework |
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| 52 | h4. Unmodified R5S |
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| 53 | 2 | laforge | |
| 54 | !20230809_233333.jpg! |
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| 56 | h4. R5S with removed resistor |
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| 58 | !20230809_233308.jpg! |
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| 60 | h4. R5S with additional pull-up resistor |
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| 62 | !20230809_233231.jpg! |
