So, today's hero is this little guy:
https://hackaday.com/tag/ch552/I'm working on my FPGA board, and part of the cost optimization is to get rid of any expensive parts (such as FT2232H), plus to get rid of parts that need pre-programming (implies DFU).
It looks like CH552E is a good option -- small package, $0.21, with HW UART/SPI, DFU bootloader, and up to 24MHz 1T 8051 core and 14kB of RAM (16kB if you nuke the bootloader).
Since it's stupidly cheap and LCSC doesn't carry it (LCSC has its TSSOP20 version, CH552T, which I don't have the PCB space for), I have to buy some from Taobao.
Due to the again, stupidly HIGH shipping cost to US (if the seller doesn't have an export license and a contract with China Post ePacket) and my bad patience, I decide to go with DHL or SF-Express.
Therefore, I'm looking at $30 on shipping for $0.21 parts, which brings the question:
Is there anyone interested in this little chip? We can make a group buy. I need 100pcs.
Some English resources of this chip:
https://www.electrodragon.com/w/WCH#MCU_.2B_USB_CH55x_Serieshttps://github.com/Blinkinlabs/ch554_sdccSome Japanese resources of this chip:
https://github.com/hakura040/CH552_SampleCodehttps://hakura03.hatenablog.com/entry/2019/03/30/115430USB DFU downloader:
https://github.com/rgwan/librech551*: CH551 is stripped down version of CH552 (no analog, less ROM/RAM, SOP16 only), which is stripped down from CH554 (removed USB host).
*: Blinkinlabs GitHub repo has a translated English document.
*: I will upload my journey with this thing on YouTube, so there will be plenty more English resource on this chip.
*: I will NOT have time to translate the whole DS to English unless WCH pays me to do so.
There was not an SDCC-version of CH552-specific header in the wild (though you can use CH554.h, just don't use registers that are not on chip), so I made my own.
Comments are stripped for the sake of formatting, I will add them back and translate them to proper English once I have spare time. Attached below.