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--- blog:articles:raspberry:phys_marsclock:pi_marsv1 [2020/10/22 14:21] – [Caveats] Phil Ide
+++ blog:articles:raspberry:phys_marsclock:pi_marsv1 [2020/11/20 11:08] (current) – [Pi-Mars v1.1] Phil Ide
@@ Line 4: / Line 4: @@
 Having written several clocks that tell the time at various locations on Mars for my [[blog:aardvaark:mars_weather|Mars Weather]] page, I immediately knew I wanted to make a physical clock - something that could sit on my desk or such like, and tell the time on Mars.
 === ===
-The Raspberry Pi was a shoe-in for the job. Items required:
+The Raspberry Pi was a shoo-in for the job. Items required:
   - Raspberry Pi 4B+ 2GbRAM (£34)
   - Power Supply Unit (£8)
@@ Line 10: / Line 10: @@
   - SmartiPi Touch 2 case (£24)
-Total cost: £130.00 plus SD card (16Gb) plus p+p.
+Total cost: ~£130.00 plus SD card (16Gb) plus p+p. An 8Gb SD card is sufficient if you want to minimalize, but a 16Gb will have a longer life.
 These were all standard components that fit together in just a few minutes. Writing the software would take a bit longer - this was after all, mainly a software task. Luckily, I'm a programmer. <- Mark Watney moment, did you spot it?.
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   * write to the SD card only when absolutely necessary, to help extend its life
   * optimised code wherever possible, but maintain flexibility and readability
+v1.1 added power management options (quit the application, reboot and shutdown).
 Optimising the code was essential. Although computers are great for repetitive tasks, making them work unduly hard at high frequency rates persistently reduces their lifespan. This clock was going to perform a large number of calculations and then repeat that task up to ten times every second (user configurable). Giving the clock a breather between each trip around the loop is just taking care of the equipment.
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+~~socialite~~
+~~DISCUSSION~~