[maxspongebob]

I have been doing conversions and full builds of systems for a while now and I am always running into the same problem. Most of my designs are based on smart controllers like the Ethernet Smooth Stepper or the Pokeys boards. What I have found is that there are several good Break Out Boards (BOBs) available but none are very sophisticated and they are all very dumb.

Most of the systems I use are Windows and Mach based. This combination is common among hobby users but when you want to add tool changers, add control consoles, or do anything more complex the BOB becomes a limiting factor.

What I want is a BOB that has an onboard Micro-controller, some communications ports (Modbus, RS-485 and RS-422) and some intelligence between the pins of the 25 pin parallel ports and the outputs. Things that would be helpful in a BOB:

• Communications ports.
• Onboard Micro-Controller(s).
• Serial LCD display port.
• Control panel/Pendant connection without 25 fricking wires.
• A single power supply for everything (12 Volts preferred).
• Multiple built in E-Stop ports.
• Motor control for a mix of steppers and ClearPath servo's (use the right connectors).
• Detection circuit for disconnected cables.
• All external connections use Shielded CAT-5/6 cables for easy connections.
• Properly ground ALL I/O.
• Some high power DC outputs to directly drive solenoids, relays, coolant pump, disconnects...
• Modbus or direct control of VFD/BLDC controller.
• Circuit for Axis error feedback.
• Simplify wiring. 1 Shielded Cat 5 for all limit switches, 1 for probing, 1 for spindle encoder.
• Easily programmable.

I am interested in finding out if anyone else is interested in this? I have the first version of the board complete where all the circuits have been tested and the software is complete.

[ger21]

I think the issue is going to be cost, as most people tend to be cheap.
I think an MB3 is more than most want to pay, and this would likely cost even more, correct?

[ericks]

I am currently working on a bob design with micro controller for added logic etc

.....also a 5 motor stepper driver board 50V/DC 0.5-6A

[maxspongebob]

I am currently working on a bob design with micro controller for added logic etc

.....also a 5 motor stepper driver board 50V/DC 0.5-6A

Sounds interesting. Lets share designs.

[ericks]

I found most bob's i used had limitations, also wiring to them was a pain so i decided to make my own and add logic with the micro. Due to work and other commitments it's a slow process. The 5 motor controller is to have the five drives and have it in a compact unit yet with 24V i/o. This 5 drive unit design is progressing...drives sorted and tested, busy with the serial comms between the micro and the motor drives. There will be two way comms between the micro and each individual drive

[maxspongebob]

I am using a little different approach. I use the ESS to provide all the Motor control signals (Step, Dir, Enable) and I feed it some limits. All the rest of the I/O from the ESS comes from/to the micro-controller. This lets me use a single cable to talk to all the rest of the devices like VFD, Consoles with lots of switches, MPG's, Relays. My BOB will support 6 motors, spindle control, Limit switches, probes, E-Stop, and whatever else you can connect to it via the serial port or via Modbus.

The BOB has 2 micro-controllers on it. They are ATMEGA1284's. Each one has an RS-485 port, an RS-422 port, a FTDI port, and an I2C port. The I2C port provides inter MCU comms.

Most of the connections to the board are via shielded RJ-45 connectors.

I will post my schematics if you are interested.

[ericks]

I am using the uc400eth for the motor signals...the micro is for additional programmable i/o and stepper drive configuration and monitoring

[ericks]

Good luck on your project, it sounds very interesting !!

...for my design i an using a pic micro

[ericks]

How is your project going?

With mine i have done the communication between the drives and micro, now busy experimenting with isolation. Using my old pc with parallel port....making sure i get the isolation/interface right.

[maxspongebob]

I'm still waiting on some IC's to arrive. The USB interface chips are coming from China and COVID has everything backed up in customs.

Post a schematic, I am interested to see what you have. I usually use optoisolators when doing that type of interface where a level shift is occurring also. Differential/Receivers have a good bit of isolation as well and are very immune to noise.

[ericks]

I'm still waiting on some IC's to arrive. The USB interface chips are coming from China and COVID has everything backed up in customs.

Post a schematic, I am interested to see what you have. I usually use optoisolators when doing that type of interface where a level shift is occurring also. Differential/Receivers have a good bit of isolation as well and are very immune to noise.

Not good...hopefully you will get them soon. I am using my old LPT port pc and Mach3 for testing. The bus transceiver i used for level shifting seem to work well, still deciding whether to add high speed opto couplers for step/dir signals too.
No issues with motion through Mach3....Sorry i don't have a schematic to post

[Sterob]

Very interesting projects guys.

Sent from my SM-G920I using Tapatalk

[ericks]

Wondering how your project is progressing?

[maxspongebob]

While waiting for those chips, several other projects got priority. I automated a good portion of my ammunition reloading process and built a 3D printer. So I have still not gotten back to it, but it is still on the list.

That reminds me, I did not create a build thread for the printer.

[maxspongebob]

Here it is.
https://www.cnczone.com/forums/gener...ml#post2396750

[ericks]

While waiting for those chips, several other projects got priority. I automated a good portion of my ammunition reloading process and built a 3D printer. So I have still not gotten back to it, but it is still on the list.

That reminds me, I did not create a build thread for the printer.

Sounds very interesting...good work

[maxspongebob]

I had let this project languish for a while but now I am back on it. Here is a block diagram of the board. An actual board will be ready in a couple weeks.

Here are some of my design ideas that I used to define how the board works.

1. Basic functionality includes I/O for limit switches, 6 step/direction motors, multiple E-Stop inputs, VFD spindle ready, switched high power outputs for disconnects and solenoids.
2. Make the board simple and usable for a person who is a beginner programmer. This means that if you don't want to wright your own code the board will work for you with basic functionality.
3. Minimize the custom cabling going to the machine. This means that the I/O is mostly wired using a standard STP Cat5 cable. These shielded cables are properly grounded and impedance matched to the circuitry. I/O signals are also all differential to eliminate EMI and allow very long cables.
4. Wherever I could, things like limit switches, encoders, console switches will have a BOB extender board that is mounted on the machine. This simplifies the wiring between the machine and the controller.
5. Advanced features that will require programming include 2 RS-485 (Modbus) ports, 2 RS-422 ports, USB ports. These ports are intended for Manual Pulse Generators, console LCD's and switches, low speed I/O for things like tool changers, Modbus control of VFD's and PLC's.
6. Use a single 12VDC power supply for all devices and eliminate excess power wiring for each device. Something like an encoder that requires 5VDC is powered from the Encoder BOB extender board. There is no power supply for +5 volts in the control cabinet to power the encoder. 12 volts is sent through the Encoder Cat5 cable to the BOB extender where 5VDC is produced for the encoder. The encoder sends it's 5V signals back to the BOB and they are sent back to the ESS over the Cat5 cable.
7. All 3 ports of the Ethernet Smooth Stepper are used and every bit is wired. Some of the ESS I/O has a dedicated function like E-Stop or Step/Dir. Some of the ESS I/O is programmable and can be used as either input or output based on your needs and ability to use the BOB micro-controllers. At least 16 bits of I/O is configurable by the user.
8. The BOB has 2 Atmel Micro-Controllers. These are ATMEGA1284P. There are 2 so that as your machine expands you can test and debug your code for new functions without modifying the existing/working code. Onboard there are 2 SPI ports, and 2 USB ports for programming functionality. There is also a L2C port that can be connected to other devices like a LCD screen for information and status/debug display.

Here is the block diagram for the board.

[maxspongebob]

I finally received the board and populated it. Yes, it looks "Old School". Some of the components are SMD, but most are through hole. A couple more weeks of testing and software debug and it should be fully functional. That is an Ethernet Smooth Stepper mounted upside down. One 12 Volt connection powers everything including the external interface boards. Chips are socketed so that you can replace one if the smoke gets out.

BOB before configuration and programming.


In addition to the main board there are other small interface boards that mount on the machine where needed.

Limit switch interface


Encoder Interface


Console Controller with I/O for 10 switches and 3 MPG's.

[maxspongebob]

Also I wanted to post a pic of the console I created for my router. Now that all my machines will get a standardized interface (RS422 port). This can be plugged into the lathe, mill, or router and all the controls will be customized for where it is plugged in.

[joeavaerage]

Hi,
like you I decided to make my own breakout board for my ESS, then I could have exactly what I want and nothing that I don't.

My breakout board was split int two boards, well technically three as there is a power supply board also.

Board 1:
Connected (ribbon cable) to port 1 of the ESS
10 differential outputs for up to five step/dir axes.
1 output Enable-to all servos
1 output Reset-to all servos
5 inputs Alarm-one per servo
1 24VDC output switched with Enable signal for Z axis electromagnetic brake

Board 2:
Connected (ribbon cables) to ports 2 & 3 of ESS, pins 2-9 of each port as inputs.
26 general purpose inputs (24VDC sourcing 5mA) (6 Limit switches, 3 Home switches, 1 Probe input, 5 wired pendant inputs)
1 output- relay for spindle on/off
1 output- spindle PWM
1 output- coolant pump SolidStateRelay
5 general purpose outputs (24VDC totem pole ie sourcing or sinking up to 50mA)

I have had these boards in service now for six months and they work well. There are a number of improvements I wish to make, and so will design and build another
over the next few months.

I used high speed dual op-amps to generate the differential step/dir signals but am less than happy about noise immunity of them. I will use a dedicated line driver IC (AEIC7272) in my next board.
The linearity of analog voltage output to PWM duty cycle is fair , about 90%. My next design will have totem pole output prior to the LPF for 97% plus linearity
I have a second spindle based on an AC servo, so my next design will have six step/dir outputs that would allow me to use the secondary spindle as a C axis for rigid tapping.
My next design will be on one PCB that the ESS plugs in directly rather like yours or an MB3.

Craig