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+# Precision Clock Mk IV
+
+Source code for the [Precision Clock Mk IV](https://mitxela.com/projects/precision_clock_mk_iv)
+
+There are three software projects, compiled with STM32CubeIDE:
+
+- mk4-time is the main clock source code running on the STM32L476
+- mk4-date is the secondary display running on the STM32L010
+- mk4-bootloader runs on the STM32L476 to do firmware updates
+
+In the QSPI folder, there are scripts to create firmware images with CRC that the clock will recognise, along with the scripts to create the tzrules and create a valid disk image, see [these notes](qspi/qspi.md) for more info.
+
+Timezone detection is ported from [ZoneDetect](https://github.com/BertoldVdb/ZoneDetect) by Bertold Van den Bergh and uses shapefile data from [Timezone Boundary Builder](https://github.com/evansiroky/timezone-boundary-builder) by Evan Siroky.