The COVID-19 pandemic has caused a global semiconductor shortage, caused by partial shutdowns of integrated circuit production facilities due to the global lockdowns early 2020 as well as marked increase in the demand of computers and consumer electronics. As a result, many commonly available chips have become totally unavailable or the price has increased many times over. For example, a common real-time clock chip, DS3231MZ used in SH-RPi cost USD 1.61 in low quantities in August 2020, but now the price has increased to over USD 7 at low quantities, with ship date estimates around May or July, 2022. Some of these components can be easily replaced, but most require at least a partial PCB design with prototype rounds and EMC pre-compliance testing.
Sailor Hat with ESP32 (SH-ESP32) has faced shortages of the power supply buck converter chip as well as the isolated CAN transceiver. A new board revision to replace the chips has been designed and tested and a new batch is soon available. The version with an external antenna connector, SH-ESP32-ufl, has still plenty of stock.
Sailor Hat for Raspberry Pi (SH-RPi) has had issues with the aforementioned RTC chip. We have just received a new batch of boards and will update the stock as the boards are finalized and tested, but they are without the RTC (the sh-rpi-nortc version). If you have a strong preference for the RTC, I recommend making some lemonade out of the lemons: as shown in the image above, using a beefy Raspberry Pi Compute Module 4 together with a suitable IO board such as the Waveshare CM4-IO-BASE-B will actually give you a much improved embedded computer. The Waveshare IO board includes an RTC chip, and the CM4 has built in eMMC mass memory that is both faster and more reliable than separate MicroSD cards. Additionally, the combination has significantly lower power consumption that a Raspberry Pi 4B, and also incorporates an M.2 M key expansion connector that accepts NVME SSD drives. The end result is a more capable computer with a lower power consumption, while still having the same footprint as a regular Raspberry Pi 4B!