spacelab-ufsc/daughterboards

OBDH 2.0 daughterboards

daughterboards's Issues

Use the spreeadsheet "PCB Design Checklist" for the ADCS DB project

This is just a sugestion, when i was developing the memory expansion daughterboard it help me a lot for reviewing and checking the PCB. The spreeadsheet made by @krgouveia can be found in this link: https://github.com/spacelab-ufsc/pcb-library/blob/master/File%20Templates/PCB%20Design%20Checklist.xlsx, any doubts about the topics on the checklist you can ask me.

Perform a Multi Board Assembly between the Daughter Board and OBDH 2.0

Multi Board Assembly

Add a PDF file with the schematics and top/bottom view of the 3D model of the PCB

Example: Schematic_OBDH_Eng_Model_2_ALT_v02.pdf

Define architecture and topology

Create 4 core schematic files: 0_Architecture, 1_Interface, 2_Non_Volatile_Memories and 3_Communication_Buffers.

Use two non volatile memory types (micro SD card and NOR flash, MT25QL01GBBB) and 1 SPI buffer (SN74LVC125A or similar).

Create the PCB layout

Preliminary Placement Suggestion:

Light brown: SD card
Dark red: NOR Flash Memory
Light blue: Buffer IC
Green: 2.54mm Pitch Debug Headers
Small blue and green shapes: Passive components (resistors, capacitors and diodes)

Create the "1_Interface" schematic sheet

Create the OBDH female connector(Samtec FSI-110-03-G-D-AD), Power on 3V3 LED and Debug Headers (before and after SPI buffer MOSI, MISO, CLK and CS signals and alternative power supply source).

Update output files and documentation with the new changes to silkscreen layer

Changes to silkscreen are: 57cfcc7 and bf312a2

Create the "2_Non_Volatile_Memories" schematic sheet

Create SD card circuits (slot SD, capacitors and pull-up/down resistors) e NOR Flash Memory (memory, capacitors and pull-up/down resistors).

Nor Flash Memory: (MT25QL01GBBB8ESF)

From the datasheet (page 79):

"Normal precautions must be taken for supply line decoupling to stabilize the VCC supply. Each device in a system should have the VCC line decoupled by a suitable capacitor (typically 100nF) close to the package pins. At power-down, when VCC drops from the operating voltage to below the power-on-reset threshold voltage shown here, all operations are disabled and the device does not respond to any command."

Reference design: Technical Note - PCB Layout Design Guidelines

SD Card: (WM12834CT-ND)

Memory expansion board documentation

Document the project of the memory expansion daugtherboard (datasheet or user manual). Example of documetation: https://github.com/spacelab-ufsc/obdh2/blob/master/doc/build/obdh2_doc.pdf

Finish remaining output files for project

1-) .OutJob file configuration
2-) BOM.xls
3-) QUOTE.xls
4-) SCH.pdf
5-) GERBERS.zip
6-) NC Drill files.zip
7-) Pick and Place files.zip
8-) ODB++.zip

Create the "0_Architecture" schematic sheet

Create block diagrams, functions and features description, version compatibility, credits and additional info.

Create the "3_Communication_Buffers" schematic sheet

Use 4-wire buffer for the SPI channel (SN74LVC125A or similar)