As well as providing the ability to automatically timestamp Project Oberon files it can be used with the Astrobe HCFiler filesystem functions to implement accurate datalogging applications.
The RTC device is available as a convenient Deadon RTC breakout board from SparkFun:
- DS3234 Breakout
- rtc.jpg (16.6 KiB) Viewed 37315 times
(There are cheaper knockoffs of the breakout board available on the Internet. However, we tried a couple and wasted a whole lot of time before realising that the battery backup didn't work on both so be warned ...)
What you need to do to make it all happen:
1. Unzip the attached source code files into the folder containing System.Mod and Oberon.Mod.
2. Connect the breakout board to the corresponding pins of the SPI1 port of a Project Oberon system. e.g. the Pmod-D port of the Digilent Arty-7 and Arty-S7 FPGA Development boards. Note: for these systems the GND and VCC connections are reversed.
3. The RTC device uses SPI Mode 3. This requires a change to the RISC5 Verilog file SPI.v :
Change the 0 in the following line to a 1:
assign SCLK = (~rst | rdy) ? 0 : fast ...
i.e.
assign SCLK = (~rst | rdy) ? 1 : fast ...
(a big thanks to Paul Reed for suggesting this change!)
4. Regenerate the FPGA Bitstream file using the Xilinx tools and reconfigure your target FPGA board.
5. Add RTC to the IMPORT list of Files.Mod, Oberon.Mod and System.Mod and replace calls to Kernel.Clock and Kernel.SetClock in those modules with the corresponding calls RTC.Clock and RTC.SetClock.
6. Rebuild your Project Oberon system.
7. Restart Project Oberon and enter the command System.Date with the current date and time in dd/mm/yy hh:mm:ss format to set the date. Enter the command System.Date without any parameters to display the current date and time:
- System.Date Screenshot
- SystmDate.JPG (51.49 KiB) Viewed 37315 times