STM8 HID Multimedia Dial
This is a USB HID with a rotatory encoder. This is used to supplement old keyboard layouts by providing a more natural alternative.
Details: https://hw-by-design.blogspot.com/2018/07/hid-multimedia-dial.html
This is a port of my HID Dial project (ATMega8) to STM8S003 using STM8 VUSB library.
STM8 VUSB
The firmware only USB stack is an unofficial fork from STM8S-VUSB-KEYBOARD at https://github.com/BBS215/STM8S-VUSB-KEYBOARD
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Works with current special edition of Cosmic C (4.4.10) and current version of STVD (4.3.12)
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USB stack logic is modified for this tech demo. HID is now working.
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Code reformatted/refractored. Using my own IRQ files for STM8S003 for a much cleaner organization. Some code logic changed.
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No longer need a separate GPIO for the 1.5K pull up to connect/disconnect USB. See schematic.
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Device library calls have been changed to bare metal to minimized dependancy and reduce code size. stm8s_flash.c is the only library needed.
Note:
The USB stack calibrates the HSI clock while connected to the PC. The calibration is store in EEPROM. It can take a couple of minutes the first time before it functions correctly.
Timer 1 is used by the USB stack for filtering and interrupt. It is not actually used for counting.
Install a 10K into R1 and 3 0.1uF capacitors to the Rotary Encoder module (made in China).
Known issue & updates:
Sometimes Windows (HID) device driver would not start (error Code 10). USBtreeview would still see it as a valid USB device. This usually happen when it switched between computers (in my KVM). It happens about 5% of the time.
I have implemented a kludge that uses the hardware watchdog (IWDG) to force a reboot on the STM8 when it is not receiving host USB packets. The watchdog is activated when the encoder wheel is turned. It is not activated automatically because it causes hickups to other USB devices in UEFI/BIOS.