Here's a rendering of the final layout with more of the big parts on it:
- ORDuinos on the way!
Apologies for the crude rendering , unfortunately my cad program has no control over color of imported 3D models. and i searched high and low and couldn't not find a step model of a simple SMT electrolytic capacitor, for the 10x10mm caps on the board. Those are overkill anyway, i may only need 1 or 2 of them after testing.
The board is 6.85" x 2.5" or 174mm x 63.5mm- Here's a quick tour:
Pluggable 3.5mm pitch terminal blocks for all 5 motor channels (including 2 digitial io's for engstops) on top edge
the 3 thermistor channels + 1 thermocouple input on the right,
and 3 more thermocouple inputs, and optional RS-485 on right bottom edge.
to the left of that is a piezo buzzer (quite loud) on a PWM pin so you can tweet any kind of melody, not just a boring 4kHz screech.
next to that is the LCD connector, then USB obviously ...
to the left of that there is the switching regulator so no problem running off 24v
beside that there's a 3-pole 5mm pluggable terminal for the 3 heater control channels-
then on the left of that the FFC connector for the special flex cable version of my heated build plate.
Right above those are more 1/4 Faston connectors for a more direct high-ampacity connection for the 3 heater outputs - the 4th on the left is heater +V power, fused at 20A.
The same connectors also serve double duty as heatsinks for the mosfets just above them.
Those have extra circuitry added for robust protection from ESD and short overvoltage events.
Also current monitoring circuitry so that can be displayed in software, and overcurrent limits can be implemented that way quite easily.
And there is a thermistor right in-between the first 2 mosfets for similar temperature monitoring and overtemp shutdown in software.
The other 3-pole terminal block to the left has the same power outlet for the heaters on the right and 2 others sharing a 10A fused circuit for extruders. Above it is another Faston tab to access that 10A circuit.
The last 2 faston tabs above that are GND and VIN. In their place i can also mount a vertical barrel jack for DC adapters- but that's not all -
In fact there are way too many options to get power into this board, and due to size restrictions its impossible to populate all of them at the same time so you will have some choices when you order :
The connector on the lower left corner is for ATX supply PCIe / CPU power cable- it can be populated as a 4-pin or 6-pin version - note you cant plug a 4-pin cable into a 6-pin socket.
Not shown is the 4-pin DIN connector in the same location on the board, which is compatible with a popular make of high-current DC adapters (laptop-style).
Right above that is another 6-pin rectangular connector, (identical to the ATX PCIe ) but a different pinout for a different brand of high-current AC-DC adapter. don't get them mixed up! Above that is yet another 3-pin pluggable terminal block for power and GND input, with an optional separate voltage input just for the motors.
Finally above that is the last optional Faston tab for same motor voltage. Motor power is fused 5 A as well as diode protected.
Just to the right of all that ( in translucent) is the 20-pin ATX motherboard connector (right-angle). this is experimental, i wont recommend that without a separate 12V inlet from the ATX supply as that only has one 18AWG wire for 12V out of the 20! but a nice feature is the 5V standby will power the CPU which also has control authority to switch on and off the main ATX supply. To use this the local switching regulator has to be disabled or not installed.
The production version of this board will likely see some of the less popular connectors eliminated , and the rest rearranged a bit for better spacing & access .
Finally skipping back to the CPU in the middle, you can see the SD card hovering over it -
On the left you have the DAC for setting the motor current limits, and the redundant trim pots near there too (one of them went for a stroll and took a nap just below the dip switches on the right of the CPU.) just above the dip switches there are the 4 R/C servo outputs(perfect for BLDC spindle motor control
There are 7 mounting screws, sized M2.5 or 4/40 ; these arranged in line through the row of motor driver IC's to insure close thermal coupling to the heatsink/ mounting bracket / handle. As you can see he layout is extremely dense (more than i expected) so not much room for more mounting points in the corners or other extra features discussed like E-stop etc. Maybe the production revision will see those added, stay tuned....
Edit: Re LCD: if you're interested in how it looks and how to use it from Arduino code, i found a compatible library with examples here and a video to go with it :
http://henningkarlsen.com/electronics/library.php?id=49http://www.youtube.com/watch?v=NoIY95XP ... e=youtu.be