LAOS Mainboard v0.3¶

• Table of contents
• LAOS Mainboard v0.3
  • Design files
  • Bill of materials
    • Common parts
  • Connectors
    • Phoenix
    • JST (HPC LS3020 Pro)
    • JST (HPC LS3020)
  • Pololu Stepper Drivers
  • Other parts
    • Power regulation
  • Older versions
  • Attachments

Design files¶

The KiCAD design files for this PCB are available on Github, see https://github.com/LaosLaser/Hardware/tree/master/laos-board-rev3

For a PDF of the schematics, as well as a top view image of the board, see the attachments at the end of this page.

Bill of materials¶

The BOM lists all recommended components. You will need to modify this list to suit your needs. Common choices:

• Connector types. The HPC laser uses JST connectors. Our reference design uses Phoenix connectors, they are nice but not cheap. You may omit connectors for functions you do not require.
• The 7805 voltage regulator (U3) is not needed if you have a stable 5V power supply.
• The pololu steppers (J8,J17,J23,J32) can be omitted if you use external steppers.
• The TIP110 (or equivalent) transistors (Q1,Q2) and associated components can be omitted if you do not want to switch external 24V loads.
• The CAN bus transceiver (U1) and associated components can be omitted, as the CAN bus is not in use by the firmware yet.
• The USB connector can be omitted. USB file systems are not implemented yet in the firmware yet.
• R2 and R3 can be omitted if you use an Ethernet connector without LEDs (one would suffice, as they both just connect to the power supply).

The Ethernet connection and the SD card are essential parts of this design.

Common parts¶

These parts are needed for every board, no matter the type of laser it will be used for.

Count	Component	RS Part No.	RS Price	Farnell Part No.	Farnell Price	Comment
1	ARM mbed LPC1768 Module	703-9238	€ 49,53	1761179	€49,73	Mbed
1	Hirose DM1B-DSF-PEJ	685-0788	€ 2,22	1764373	€2,65	reverse SD Memory Card connector
2	DIL socket,0.3in pitch, 16 pin	402-771	€ 0,18	1077315	€2,17
2	Harwin M20-7832046	681-6851	€ 5,31	9688862	€ 7,07	Mbed Footprint
1	MAGJACK SI-60002-F	741-8477	€ 4,38	1137981	€6,27	Network connector (with LEDs: Farnell:1137983)
2	IC KB847	619-2026	€ 1,96	2001656	€1,37	(5 pcs min)
1	2GB SD card	539-7804	€ 9,40			SD Card (cheaper at Mycom: € 4,99)
1	100R resistor	707-7587	€ 0,02
1	120R resistor	707-7599	€ 0,02
4	330R resistor	707-7622	€ 0,02
15	1K resistor	707-7666	€ 0,02
2	2K2 resistor	707-7690	€ 0,02
11	10K resistor	707-7745	€ 0,02
5	100nF capacitor	721-5240	€ 0,07
1	22nF capacitor	721-5268	€ 0,12
1	100 µF capacitor (ELCO)	520-0996	€ 0,28			min. voltage: 12V
1	1000 µF capacitor (ELCO)	520-1090	€ 1,31			min. voltage: 25V (depending on your motor voltage)
1	Red LED	708-2753	€ 0,09
1	Green LED	708-2756	€ 0,11
1	Yellow LED	708-2769	€ 0,11
1	Laos PCB Rev 0.3		€ 15,00			Available from our WebShop

Connectors¶

Phoenix¶

Count	Component	RS Part No.	RS Price	Farnell Part No.	Comment
7	Phoenix 4-pin terminal block	189-6032	€ 3,05	3705377
7	Phoenix 4-pin PCB header	189-6127	€ 1,04	3705195
3	Phoenix 2-pin terminal block	189-6010	€ 1,746	3705353
3	Phoenix 2-pin PCB header	189-6105	€ 0,51	3705171
1	pin-header 1x4	251-8632	€ 1,056

JST (HPC LS3020 Pro)¶

The HPC LS3020 Pro uses low cost JST connectors on their cables.

Count	Component	RS Part No.	RS Price	Farnell Part No.	Farnell Price	Comment
1	WUERTH ELEKTRONIK 3WAY PCB connector RIGHT ANGLE 5.08mm	189-6571	€ 0,62	1641987	€ 0,60	PCB Power connector
5	JST 4 pin PCB connector B4B-XH-A (LF)(SN)	543-2733	€ 0,16	1516278	€ 0,20	Stepper drivers, Endstop & Laser and I2C
2	JST 4 pin housing XHP-4	353-1636	€ 0,07	1516266	€ 0,10	For endstop and laser cable (usually provided with laser)
1	JST 2 pin housing XHP-2	353-1614	€ 0,05	1516264	€ 0,05	To add laser power modulation
2	JST Socket insert BXH-001T-P0.6	353-1591	€ 0,04	1516301	€ 0,05	To add laser power modulation

Note - You need to modify the cables a bit to connect to the correct pins, see description in the HPC installation section. Connectors may have significant minimum order quantity. You may ask Peter if he has some he can supply when ordering the PCB.

JST (HPC LS3020)¶

The HPC LS3020 uses low cost JST connectors on their cables.

Count	Component	RS Part No.	RS Price	Farnell Part No.	Farnell Price	Comment
1	WUERTH ELEKTRONIK 3WAY PCB connector RIGHT ANGLE 5.08mm	189-6571	€ 0,62	1641987	€ 0,60	PCB Power connector
3	JST 4 pin PCB connector B4B-XH-A (LF)(SN)	543-2733	€ 0,16	1516278	€ 0,20	Stepper drivers, Endstop & Laser and I2C
2	JST Socket insert BXH-001T-P0.6	353-1591	€ 0,04	1516301	€ 0,05	To add laser power modulation
1	FFC / FPC connector	718-8772 (straight, untested)	€ 0,18	1816463	€ 0,30	This connector combines X-axis and endstops!

Pololu Stepper Drivers¶

Number	Component	RS Part No.	RS Price	Farnell Part No.	Farnell Price	Comment
2-4	Pololu stepper drivers					Depending on how many axes your machine has
4-8	8x1 pin-header socket	495-8587	€ 1,25	3419101	€ 0,56	You need 2 for each Pololu

The Pololu you need is of the type A4988: http://www.pololu.com/catalog/product/1182

We recommend a heatsink with the pololu, as sold here: ultimachine.com and here: reprap.me

Other parts¶

Number	Component	RS Part No.	RS Price	Farnell Part No.	Farnell Price	Comment
1	7805	398-697	€ 0,23			Power regulation (see below)
1	2x4 DIL socket	402-759				Canbus IC holder
1	65HVD251 CAN chip	662-4321				Canbus IC
1	USB connector	719-9438		1642033		Usb Host connector
1-2	TIP 110	485-9648		9294201		Analog output

Power regulation¶

If your laser does not have a good 5V power supply built-in, you can add this 7805 power regulator. Note that it will get very hot if you feed it a high voltage. Anything between 7 and 12 volt should be ok. You can use a left-over power adapter to power the board.

The HPC series have a 5V power output built-in.

Older versions¶

The history of mainboards is available in Mainboard_Revisions

Attachments¶