E7EPD Database Specification

Rev 0.5

Specification Notes

Components

All components, when specified, will be based of the GenericPart table spec that contains common columns. Note that the GenericPart table doesn’t exist by itself but is used in this document as columns that every other table should have

Different Tables Per Components

To allow for the parameterization of parts, and due to SQL’s column nature where it’s usually unchanged, each specific component type (like resistors, IC, etc) will have its own SQL table.

Table Spec

GenericPart Table

Name	SQL Type	Required?	Description
id	INTEGER PRIMARY KEY	YES	Each row in the database will contain an unique SQL ID
stock	INT	YES	The number of parts in stock
mfr_part_numb	VARCHAR	YES	The manufacturer part number, used to distinguish each part from another
manufacturer	VARCHAR		The manufacturer of the component
package	VARCHAR	YES	The part’s physical package
storage	VARCHAR		The part’s storage location
comments	TEXT		Comments about the part
datasheet	TEXT		The datasheet of the part

Resistor Table

Append the GenericPart Table to this table. Table Name: resistance

Name	SQL Type	Required?	Description
resistance	FLOAT	YES	The resistor’s resistance
tolerance	FLOAT		The resistor’s tolerance as a float (so a 5% resistor will be stored as 5)
power	FLOAT		The resistor’s power rating in W

Capacitor Table

Append the GenericPart Table to this table. Table Name: capacitor

Name	SQL Type	Required?	Description
capacitance	FLOAT	YES	The capacitor’s capacitance
tolerance	FLOAT		The capacitor’s tolerance as a float (so a 5% capacitor will be stored as 5)
voltage	FLOAT		The capacitor’s maximum voltage rating
temp_coeff	VARCHAR		The capacitor’s temperature coefficient
cap_type	VARCHAR		The capacitor types, which should only be ‘electrolytic’, ‘ceramic’, ‘tantalum’, ‘film’. If a type is not listed, you can enter a custom type, just make sure that it’s consistent for different parts (also create an Issue on the Github page so we can all have it :)

Inductor Table

Append the GenericPart Table to this table. Table Name: inductor

Name	SQL Type	Required?	Description
inductance	FLOAT	YES	The inductance of the inductor
tolerance	FLOAT		The inductor’s tolerance as a float (so a 5% inductor will be stored as 5)
max_current	FLOAT		The inductor’s maximum current

Diode Table

Append the GenericPart Table to this table. Table Name: diode

Name	SQL Type	Required?	Description
diode_type	VARCHAR	YES	Diode Type (Regular, Zener, Schottky, etc)
max_current	FLOAT		Max/Peak Current
average_current	FLOAT		Average Current Rating
max_rv	FLOAT		Max reverse voltage

IC Table

Append the GenericPart Table to this table. Table Name: ic

Name	SQL Type	Required?	Description
ic_type	VARCHAR	YES	The IC type, for example microcontroller, ADC, comparator, etc.

Crystal Table

Append the GenericPart Table to this table. Table Name: crystal

Name	SQL Type	Required?	Description
frequency	FLOAT	YES	The frequency of the crystal
load_c	FLOAT		The load capacitance (in pF) of the crystal
esr	FLOAT		The ECR (in Ohms) of the crystal
stability_ppm	FLOAT		The stability (in ppm) of the crystal

MOSFET Table

Append the GenericPart Table to this table. Table Name: mosfet

Name	SQL Type	Required?	Description
mosfet_type	VARCHAR	YES	The MOSFET type (N-Channel or P-Channel)
vdss	FLOAT		The max Drain-Source voltage of the MOSFET
vgss	FLOAT		The max Gate-Source voltage of the MOSFET
vgs_th	FLOAT		The Gate-Source threshold voltage of the MOSFET
i_d	FLOAT		The max continuous drain current of the MOSFET
i_d_pulse	FLOAT		The max pulsed/peak drain current of the MOSFET

BJT Table

Append the GenericPart Table to this table. Table Name: bjt

Name	SQL Type	Required?	Description
bjt_type	VARCHAR	YES	The BJT type (NPN or PNP)
vcbo	FLOAT		The max Collector-Base voltage of the BJT
vceo	FLOAT		The max Collector-Emitter voltage of the BJT
vebo	FLOAT		The max Emitter-Base voltage of the BJT
i_c	FLOAT		The max continuous collector current of the BJT
i_c_peak	FLOAT		The max pulsed/peak collector current of the BJT

Connector Table

Append the GenericPart Table to this table. Table Name: connector

Name	SQL Type	Required?	Description
conn_type	VARCHAR	YES	The connector type (Banana, Rect. Header, Test point, etc)

LED Table

Append the GenericPart Table to this table. Table Name: led

Name	SQL Type	Required?	Description
led_type	VARCHAR	YES	The LED’s color (Red, Blue, RGB, etc)
vf	FLOAT		The LED’s forward voltage
max_i	FLOAT		The LED’s maximum forward current

Fuse Table

Append the GenericPart Table to this table. Table Name: fuse

Name	SQL Type	Required?	Description
fuse_type	VARCHAR	YES	The fuse type (Glass, PTC, etc)
max_v	FLOAT		The fuse’s max voltage
max_i	FLOAT		The fuse’s absolute maximum current
trip_i	FLOAT		The fuse’s trip current
hold_i	FLOAT		The fuse’s hold current

Button/Switch Table

Append the GenericPart Table to this table. Table Name: button

Name	SQL Type	Required?	Description
bt_type	VARCHAR	YES	The button/switch type (Tactile, Rocker, etc)
circuit_t	VARCHAR		The button/switch’s configuration (SPDT, SPST-NO, etc)
max_v	FLOAT		The button/switch’s max voltage
max_i	FLOAT		The button/switch’s absolute maximum current

Misc Table

This table is exactly the same as the GenericPart Table. Table Name: misc_c

PCBs

Each PCB will have parts associated with it. This should allow the user application to determine if it’s possible to build up a board given the current component’s stock.

PCB Table

Table Name: pcb

Name	SQL Type	Required?	Description
id	INTEGER PRIMARY KEY	YES	Each row in the database will contain an unique SQL ID
stock	INT	YES	The number of parts in stock
board_name	VARCHAR	YES	The board’s name. Can also be thought of as the project’s name
rev	VARCHAR	YES	The pcb’s revision
sub_rev	VARCHAR		The pcb’s sub-revision
comments	TEXT		Comments about the part
parts	JSON	YES	A JSON list containing all of the parts used for this project

Parts JSON List

The parts JSON is a list of dictionaries containing the all parts used for a particular board.

The dictionaries in this list is formatted as follows for a component:

Key	Value Type	Description
comp_type	string	The component type (resistor, bjt, etc) which corresponds to the part’s table name
part	dict	A dictionary describing the part
qty	int	The quantity of this part used in this board
alternatives	list	A list of alternative parts that can be used, each part being the same format as the part key above. This list can be left as an empty array.

The part key above is a dictionary containing a set of filter key-value pairs that narrows down a part. For example, for a part with the manufacturer part number of “PART123”, the part dict would be .. code-block:

{
    mfr_part_numb: PART123
}

As the manufacturer part number is unique to each part, this filter would only find a single part. With a resistor for example, where a specific part does not matter, the part dict would look something like .. code-block:

{
    resistance: 1000
    power: >0.125
    package: 0805
}

The > prefix in power: >0.125 indicates that the power value must be greater than 1/8W, and anything above that is fine as well.