Industrial io board

Baseboard for industrial applications. Project Finished

Board Box open



Project background

The idea is to create base board for mbed that could be installed and used in industrial environment. Possible applications could be, from monitoring production equipment to PLC applications.


  1. Based on mbed NXP LPC1768
  2. 2 x RS232
  3. 4 Digital inputs (PNP, sourcing) with 2.5V logical state change, max input level +30V
  4. 4 Analog inputs (0-10V), can be used as digital inputs in 24V systems
  5. 2 Digital PNP outputs with PWM, each which can drive up to 1Amp (24VDC) based on P-MOSFET NDT454
  6. 1 Digital PNP out with 5V output shared with USB host power (even if 24V is applied as system voltage)
  7. 1 Analog out (0-10V) driven by operational amplifier (only with >10V power supply)
  8. Short circuit protected outputs
  9. Fused USB host and programming USB
  10. Onboard temperature sensor MCP9701AT
  11. both USB and Ethernet with ESD suppressors
  12. USB Host detect
  13. USB Host power reset capability
  14. External programming USB with Programming detect
  15. Hard reset (resets everything, etc mbed-interface)
  16. microSD card
  17. 4 mbed's LEDs indicate the working status
  18. Onboard prototyping area for remaining mbed pins
  19. Free locations on external connector for prototyping
  20. Aluminium enclosure supporting DIN rail installation

Power specs

  1. Board power supply: input 5V to 30VDC
  2. Onboard 5V converter 1Amp
  3. 2 power options, USB 5V or 6.5-30VDC from terminal connector. No power plug.
  4. Compatible with 24VDC industrial power supplies
  5. 1 output can supply 5V for external systems
  6. Max 30VDC voltage range e.g. cannot be used for switching 120-240VAC

8 comments on Industrial io board:

28 Feb 2012

Looks very promising.. Interested definitely!

28 Feb 2012

Good start. I also work with this kind of applications. The problem, always the wrong choice. So now I'm trying to work more with i2c extensions. An I / O with 24v inputs (2803 in reverse) and 24v darlington outputs(for (proximity)switches and solenoids). An I2C LCD board with switches on the unused io the MCP23017 or other. Btw how is the analog part working when you use only 5V.

29 Feb 2012

I noticed "DIN rail installation". Does this mean you expect the end product to operate outdoors? If so, be sure the mbed can handle your temperature / moisture requirements. ...kevin

01 Mar 2012

Thanks for replies,

Kevin Braun wrote:

I noticed "DIN rail installation". Does this mean you expect the end product to operate outdoors?

Not necessarily. DIN rail installation means that it can be installed on indoor machines. Outside installations would require a "field box" anyway. I have written page about protecting Mbed from environment Conformal Coating Mbed

hugo stoutjesdijk wrote:

Btw how is the analog part working when you use only 5V.

Yes, this configuration gives us @5V max 5V/3 at voltage divider, which is not expected maximum 3.3V for AnalogIn. We are working on that, but if there's no good ideas, then one has to expect lower voltages at AnalogIn and program the device accordingly.

01 Mar 2012

Actually analogin is not a problem, it should be working even in case we are using 5V power, but analogout won't work with 5V power, we don't get out 0 to 10V, we get only 0 to 5V, if we want to use analogout 0 to 10V, we need certainly additional power at least 10V.

12 Apr 2012

Needs at least rs232 and rs485 ports for plc connections. I see a mixture of both and is always a pain having to keep getting 232 to 485 converters.

02 Aug 2012

Hallo, it's very good idea, but my question is, do you implemented CODESYS for programming in IEC61131-3?

02 Aug 2012

Thanks for your interest, we are currently working on hardware. More to come..

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