Nokia EKSOS N20 DIY carrying case » History » Version 8
laforge, 08/27/2023 01:10 PM
1 | 1 | laforge | h1. Nokia EKSOS N20 DIY carrying case |
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3 | 7 | laforge | {{>toc}} |
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5 | 1 | laforge | 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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7 | The systems should contain |
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8 | * EKSOS N20 shelf with mandatory NCU and some subscriber line cards |
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9 | * a number of subscriber ports broken out to RJ45 connectors |
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10 | * a 48V power supply |
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11 | * an [[Osmocom_icE1usb]] plus an embedded Linux board to run TDMoIP for the V5 back-haul |
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12 | ** 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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13 | * some fans for active cooling as it is getting rather hot in the sun outdoor on a camp |
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14 | * ruggedized enclosure to make sure the equipment survives transportation unharmed |
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15 | 7 | laforge | |
16 | !20230805_160617.jpg! |
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18 | 1 | laforge | h2. Enclosure |
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20 | 3 | laforge | The enclosure is made of wooden panels. |
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22 | h3. wood corpus |
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24 | h4. Assembled enclousre body |
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26 | !20230801_203832.jpg! |
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28 | h4. Milling left and right sides to accomodate screw heads |
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30 | 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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32 | !20230801_203546.jpg! |
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34 | h4. Bottom side / gliders |
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36 | !20230801_203821.jpg! |
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38 | 1 | laforge | h3. Fans / Cooling |
39 | 8 | laforge | |
40 | h3. Bill of Materials |
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42 | |_.Qty|_.Description|_.Source| |
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43 | |2|Multiplexplatte 18mm 400x250mm (Seitenteile Korpus)|| |
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44 | |1|Multiplexplatte 9mm 480x268mm (Unterteil Korpus)|| |
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45 | |1|Multiplexplatte 18mm 480x400mm (Rückenteil Korpus)|| |
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46 | |4|Teflongleiter 22m grau|"Hornbach 6163633":https://www.hornbach.de/p/tarrox-ptfe-gleiter-mit-schraube-22-mm-rund-grau-4-stueck/6163633/ (4-pack)| |
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47 | |1|Kistenverschluss ohne Schließhaken 93x24mm|"Hornbach 734963":https://www.hornbach.de/p/kistenverschluss-ohne-schliesshaken-93-x-24-mm-galv-verzinkt-dickschichtpassiviert/734963/| |
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48 | |1|Schliesshaken für Kistenverschluss 25x33mm|"Hornbach 734974":https://www.hornbach.de/p/schliesshaken-fuer-kistenverschluss-25-x-33-mm-galv-verzinkt-dickschichtpassiviert/734974/| |
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49 | |2|Möbelband links, vernickelt 50x40mm|"Hornbach 8673847":https://www.hornbach.de/p/moebelband-links-vernickelt-50x40-mm-10-stueck/8673847/ (10-pack)| |
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50 | |2|Kistengriff Metall verzinkt 82x72x10mm|"Hornbach 8095113":https://www.hornbach.de/p/kistengriff-metall-verzinkt-lochabstand-80-mm-lxbxh-82-72-10-mm/8095113/| |
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51 | |1|Multiplexplatte 9mm 480x400mm (Vorderteil Deckel)|| |
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52 | |2|Multiplexplatte 18mm 354x100mm (Seitenteile Deckel)|| |
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53 | |2|Multiplexplatte 9mm FIXME (Ober/Unterteil Deckel)|| |
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54 | |1|Edelstahlblech 2mm 475x263mm (Luefter/Deckelblech) "eksos-fanmount.dxf":https://gitea.osmocom.org/electronics/osmo-small-hardware/raw/branch/master/eksos-fanmount/eksos-fanmount.dxf|| |
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55 | 1 | laforge | |
56 | h2. Power Supplies |
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58 | 4 | laforge | The power supplies are mounted in the rear part of the bottom panel |
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60 | !20230804_192817.jpg! |
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62 | h3. 48V: MeanWell RSP-150-48 |
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64 | This supply is used for powering all 3 rails of the EKSOS shelf: |
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65 | * odd numbered line cards |
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66 | * even numbered line cards |
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67 | * signaling voltage |
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69 | I've used the trimmer potentiometer to trim the output voltage to the maximum (+5%). |
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71 | h3. 12V: MeanWell RSP-12-35 |
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73 | This 12V supply is used to power the nanoPi R5S as well as the fans. |
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75 | 5 | laforge | h2. Subscriber port break-out |
76 | 4 | laforge | |
77 | 5 | laforge | Initially, I started with a 1U RJ45 ISDN patch panel at the bottom of the enclosure. Later, I switched to a PCBA + IDC ribbon cable approach to reduce the amount of manual labour. |
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79 | 5 | laforge | h3. Original approach: ISDN patch panel + wiring |
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81 | This approach was implemented in the first two units. It consists of |
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82 | * a 50-port 1U ISDN patch panel mounted to the bottom of the rack |
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83 | * three telephone cables of each 16x2x0.6mm |
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84 | * three DIN connectors |
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85 | * lots of heat shrink tube 1.6mm |
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87 | !20230805_090346.jpg! |
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89 | h3. Updated approach: Ribbon cable, IDC connectors + custom PCBA |
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91 | The idea of this approach was to |
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92 | * build a custom break-out PCBA which can be slided into the EKSOS shelf (removing a subscriber line card) |
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93 | * build a ribbon cable with IDC connectors towards the EKSOS subscriber line card (DIN connector) and a 64pos 2-row header (break-out board) |
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95 | h4. break-out PCBA |
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97 | 6 | laforge | The boards has 16 RJ45 connectors. The center two pins (4+5) are routed to the first (left) IDC connector. The two surrounding pins (3+6) are routed to the second (right) IDC connector. This allows a single break-out board to carry either 16 or 32 subscriber ports. |
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99 | 5 | laforge | !20230811_120723.jpg! |
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101 | h4. ribbon cable with IDC connectors |
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103 | !20230811_120736.jpg! |
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105 | h4. break-out PCBA with IDC ribbon cable plugged in |
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107 | !20230811_120809.jpg! |
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109 | h4. subscriber line cards + breakout boards installed in rack |
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111 | !20230811_140854.jpg! |
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112 | 1 | laforge | |
113 | h2. icE1usb + Linux SBC |
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115 | 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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117 | h3. nanoPI R5S 12V DC re-work |
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119 | 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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121 | 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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123 | FIXME: Describe the rework |
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125 | h4. Unmodified R5S |
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126 | 2 | laforge | |
127 | !20230809_233333.jpg! |
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129 | h4. R5S with removed resistor |
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131 | !20230809_233308.jpg! |
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133 | h4. R5S with additional pull-up resistor |
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135 | !20230809_233231.jpg! |