Cerbuino I/O Shield

Archive
1

One last board to show off.

6-36Vdc Input
32Khz RTC crystal
RTC Battery
4 - 24Vdc, 100mA Sinking Outputs
4 - 24Vdc inputs
2 - 0-10Vdc inputs (voltage divider)
1 - RS485 with SPI UART

I hope the RS485 UART works. I haven’t written the driver yet to test it. I am using the MAX3107 SPI UART with 128-word FIFO. http://www.maximintegrated.com/en/products/interface/controllers-expanders/MAX3107.html
If anyone has any experience with it and want to pass along any pointers I would appreciate it.

9 Likes
2

Nice work @ Skeller. There’s a lot to be said for the satisfaction felt when you create something from just a set of requirements. I’m waiting for a PCB that will have four mains rated zero-voltage switching triacs (4Amps) on board and another with a pair of serial-in/parallel-out and parallel-in/serial-out shift registers. Can’t wait to get them built and tested.

Good luck with the driver.

Let us know how you get on.

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Looks great. Can it already be bought? What’s the price?

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I have just ordered prototype boards for version 2.
Changes:

  • Moved battery to clear Xbee module for use on Cerbuino Bee.
  • Added SPI 2K MAC EEPROM. (Microchip: 25AA02E48)
  • 220Ohm bias resistors for RS-485 output.
  • Added level translators and solder jumpers to optionally connect RS-485 chip to TX and RX of Arduino headers. (Arduino Header RX pin (PB11/I2C/_SDA/UART3_RX) on Cerbuino NET is connect to ENC28 WOL# pin so I assume that renders that serial port unusable on the Cerbuino NET. ) RS-485 driver chip is MAX13487.

I also fixed schematic problem. I miss labeled my SPI CLK signal so no trace for CLK got routed to the SPI UART. :-[

Will update soon with progress and availability if anyone is interested.

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What’s it intended for - 24v furnace controller?

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No, I plan on using it for small industrial control applications instead of a micro PLC. (I hate ladder logic programming.)
I am sure it could be used for furnace control although I think most home furnace circuits are 24Vac not Vdc. This is designed for Vdc inputs.

I also have a G120 based board I am working on that has similar I/O. https://www.ghielectronics.com/community/forum/topic?id=16605
It is more geared to applications that require remote data logging with cellular modem, PPP and SQLite.

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@ skeller -
Dear Mr. Skeller
I’m planning to use MAX3107 to my new design.
I highly Appreciated to have your recommendations based on your pervious experiments about using this chip.
Best Regrads!