One last board to show off.
32Khz RTC crystal
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.
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.
Looks great. Can it already be bought? What’s the price?
I have just ordered prototype boards for version 2.
- 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.
What’s it intended for - 24v furnace controller?
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.
@ 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.