Past Sulu Assemblies

Owned by Joshua Alexander
Last updated: Mar 30, 2022
5 min read

Testing notes can be found at: https://docs.google.com/spreadsheets/d/14XAfxGwL6wk_KUb9GTKfo5KeL4-N5aEMuYoCTwm1jF0/edit?usp=sharing

L6/L7:

  • Sulu V1 boards

Immediately after getting boards from Digicom:

  • L6 had noticeable epoxy deformation on Quik-Pak SCuM. L7 no noticeable deformation.

  • Pin headers hand-soldered by us. Josh tested both connections to SCuM and could program both initially.

A mistake on the BOM led to inductors not being soldered on by Digicom so DC-DC converters did not work. Alex was able to reheat the solder on the inductor pads for both boards to add the inductors. Afterwards:

  • After adding the inductors, L6 DC-DC converters functional but SCuM disconnected. We thought that heating the board to the point that the inductor pad solder melted might have loosened the SCuM Quik-Pak and a very small movement might have disconnected it.

    • When tested with 1.8 V 2/11/22:

      • 300 uA on VBAT

      • 2.2 mA on VDDD

      • 0.4 uA on VDDIO

  • After adding the inductors, L7 functionality did not change. It could still easily be programmed, but DC-DC converters were still disconnected. Due to L6 issues, we decided not to retry soldering on inductors.

    • When tested with 1.8 V 2/11/22:

      • 18 mA on VBAT

      • 48.5 mA on VDDD

      • 2.3 uA on VDDIO

L8/L9/L10:

  • Sulu V1 boards

  • Pin headers soldered on by Austin.

  • All 3 boards did not draw current when connected to VBAT.

  • Due to last minute changes with which inductors were used, Digicom initially placed the old inductors and later swapped them out for the correct ones. Digicom said they looked at the board under and xray machine and the connections looked ok.

  • Deformations in L8

    • When tested with 1.8 V 2/11/22:

      • 0 uA on VBAT

      • 0 uA on VDDD

      • 0 uA on VDDIO

  • L10

    • When tested with 1.8 V 2/11/22:

      • 0 uA on VBAT

      • 0 uA on VDDD

      • 0 uA on VDDIO

L14/L15/L16:

  • Sulu V2 boards

  • L15 had noticeable epoxy deformation on Quik-Pak SCuM.

    • When tested with 1.8 V 2/11/22:

      • 425 uA on VBAT

      • 0 uA on VDDD

      • 0 uA on VDDIO

  • Pin headers soldered on by Digicom

  • L14 and L16 did not draw current when connected to VBAT. L15 did draw expected current when connected to VBAT, but did not draw current when connected to VDDD.

  • All 3 SCuM were confirmed 5 days earlier to successfully program with 3WB using the probe station.

L17/L19:

  • Sulu V2 boards

  • L19 had noticeable epoxy deformation on Quik-Pak SCuM.

  • L17 had a noticeable crack in the epoxy.

  • Pin headers soldered on by Digicom

  • No current drawn from either board from any location.

  • Both SCuM were confirmed 1 day earlier to successfully program with 3WB using the probe station.

 

L24/L25:

Digicom Assembly Steps:

Clean board and bake it to get rid of moisture

Print solder paste onto board

Use a machine to place smd components

SCuM placed by hand

Use oven to reflow.

Use no clean solder so there is no need to clean it again

Check if the board needs to be touched up

  • Both boards could be programmed to communicate with Open Mote when received from Digicom

  • No through hole components/pin headers were added initially

  • L24 has pin headers added and L25 has pin headers and SMA connector added after process below.

Austin and Josh testing results:

 

L2/L3/L4/L5/L11/L12/L13/L18/L31/L37/L43/L49

  • Assembled by Digicom using low temperature solder and no pin headers or through-hole SMA connector.

  • Before adding headers/SMA connector optical bootloader boot testing

    • L11/L12/L13/L18/L31/L37/L43/L49

      • Booted using optical bootloader

      • Normal current profile for AllGPIOToggle

      • Tested packaged SCuM 1 week before assembly

    • L2/L3/L4/L5

      • L2 has lower than expected current, but does appear to change on boot

      • L3-L5 did not appear to boot

      • Tested packaged SCuM ~4 months before packaging and assembly

        • possible mixup identifying SCuM before packaging

  • After adding headers/SMA connector to L11/L12/L13/L18/L31/L37/L43/L49

    • Confirmed to work under 3WB/optical bootloader

    • Transmits to and from SCuM to and from an OpenMote

    • Transmits IMU data over UART

 

L20/L21/L23/L28/L30/L32/L34/L35/L36/L38/L39/L40/L41/L42/L44/L45/L46/L47/L48/L50

  • Assembled by Digicom using low temperature solder and no pin headers or through-hole SMA connector as previous group of 12.

  • Before adding headers/SMA connector optical bootloader boot testing

    • L21/L23/L28/L30/L32/L34/L35/L36/L38/L41/L42/L44/L45/L46/L47/L48/L50

      • Booted using optical bootloader

      • Normal current profile for AllGPIOToggle

      • Tested packaged SCuM 1 week before assembly

    • L20/L39/L40

      • L20 Stays around 270 uA with VBAT + GND, 164 uA with VDDD also.  Does not boot

      • L39

        • See delta of ~50 uA on boot as if a Tap board without VDDD, but see no change on boot with VDDD connected

        • Could just be poor connections by directly connecting wires

      • L40

        • 19-20 mA with just VBAT + GND connected.

        • Normal 0.145mA when VDDD connected, but doesn't boot

    • Tested packaged SCuM ~2 weeks before packaging and assembly

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