Tom Uban

Sigh, I missed that in the docs, or at least I've forgotten it since I built the machine at the start of 2020. Thanks for your clarification.

I have recently noticed a problem with the EEPROM save/restore functionality. As my program grew to exceed 0x80, I discovered that only the lower half of the program is restored after the program is saved, the board is powered off/on and the program is restored. I noticed this when I was able to load the program via serial and run the program without errors, but if the program was loaded, saved, the board powered off/on, restored and run again, the program would fail due to the upper half of memory...

Awesome. I would recommend making it so that a set of wires leading from the PCB line up with the In0, In1, In2 (adding push buttons for the setting of time) as well as GND and +12v :)

The computer primarily waits on the inwait instruction for a minute to pass and then does enough calculations to update the time. The inwait hold is managed in the PIC micro controller and so no relay sequencing is performed during the wait. Generally relay wear is based on contact cycles, not on time, but I guess time would tell. Load the program (clock2.asm) and try it out...

I wanted to do something with my Relay Trainer which could run for an extended period of time, but not burn out the life of the relays. To this end, I created a clock which updates once per minute based on a simple circuit (clock_timer.jpg) which uses some CMOS parts (running at 12v) to create a 1/120Hz square wave driving the In0 input. The code displays the hours:minutes in the right four digits of the bigger display and also outputs the time on the serial console. Once running, the minutes can...

I wanted to do something with my Relay Trainer which could run for an extended period of time, but not burn out the life of the relays. To this end, I created a clock which updates once per minute based on a simple circuit (clock_timer.jpg) which uses some CMOS parts (running at 12v) to create a 1/120Hz square wave driving the In0 input. The code displays the hours:minutes in the right four digits of the bigger display and also outputs the time on the serial console. Once running, the minutes can...

Changing R204 to 1.8K has made the PC much more stable.

After my coffee, my brain kicked in better and I realized that the silkscreen on the board might indicate which relays could be the problem. I swapped a couple a couple of times and it seems better now, but bit 5 still seems on the edge. I guess I'll keep fiddling with them if it contues to flake out, at least until I run through the few extra relays I purchased.