LAOS Laser

h1. LAOS Mainboard v0.3

{{>toc}}

!>DSC_3506.jpg!

h2. 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.

h2. 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. 

h3. 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|Laos PCB Rev 0.3| |€ 15,00| | |Available from our WebShop: http://wiki.laoslaser.org/index.php/WebShop|

|1|2GB SD card|539-7804|€ 9,40| | |SD Card (cheaper at Mycom: € 4,99)|

|1|ARM mbed LPC1768 Module|703-9238|€ 49,53|1761179| €49,73|Mbed|

|1|Hirose DM1B-DSF-PEJ(82)|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|100R resistor|707-7587|€ 0,02|9339043| ||

|1|120R resistor|707-7599|€ 0,02|9339116 | ||

|4|330R resistor|707-7622|€ 0,02|9339418 | ||

|15|1K resistor|707-7666|€ 0,02|9339051 | ||

|2|2K2 resistor|707-7690|€ 0,02|9339302 | ||

|11|10K resistor|707-7745|€ 0,02| | ||

|4|100nF capacitor|721-5240|€ 0,07| | ||

|3|22nF capacitor|721-5268|€ 0,12| | ||

|4|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| | ||

h2. Connectors

h3. 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| | |

h3. 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|

|6|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)|

|0|JST 2 pin housing XHP-2|353-1614|€ 0,05|1516264|€ 0,05|To add laser power modulation|

|10|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 [[Installation_HPC|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.

h3. 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!|

h2. 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":http://ultimachine.com/content/pololu-a4988-stepper-driver-heatsink-kit and here: "reprap.me":http://reprap.me/epages/reprap_nu_4149051.sf/en_US/?ObjectPath=/Shops/reprap_nu_4149051/Products/Pololu

h2. 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|

h3. 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.

h2. Older versions

The history of mainboards is available in [[Mainboard_Revisions]]

h2. Attachments