The JGAurora A5S and JGAurora A1 are new printers released in October 2018. They feature a new 32-bit motherboard developed in-house by JGAurora, using Allegro A5984 stepper drivers with 32x microstepping, delivering much improved printing performance over their predecessor, the A5. Both of these printers also feature smart features like power outage resuming, and filament run out sensors. The A5S and A1 printers have large print volumes of 300x300x320 and 300x300x300 respectively.
In April 2019, JGAurora also released an updated JGAurora A3S MkII, with the same design as the previous A3S, but using the same modern 32-bit motherboard used on the A5S and A1.
For information on upgrading the A5S and A1 firmware, please see this page.
If you wish to flash the firmware but do not want to use the SD card, or if your bootloader is damaged, there is another way to flash firmware, using the SWD interface on the motherborad. Note: the pinout is completely non-standard, please see the image above, and follow the instructions below.
Connect this port up to an ST-Link V2 using jumper wires / dupont cables, and you will be able to backup and upgrade the firmware on the A5S & A1. I recommend NOT plugging in the 3.3V line, but instead provide power to the board via USB cable, and only use the data and GND lines on the ST-Link header connection. I recommend you use the STM32 ST-LINK Utility (STSW-LINK004). Please post on the jgaurora forum firmware discussion thread if you want any help with this!