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Did an experiment with a CH330n serial chip. — Parallax Forums

Did an experiment with a CH330n serial chip.

alatnetalatnet Posts: 80
in Propeller 1
Found about the CN330n serial chip.
It's around $3 + shipping on ebay and possibly cheaper on other sites (probably as low as $0.33 or so).
The only issue is that the only datasheet is translated from a poorly made chinese datasheet.
Chinese datasheet: https://datasheet.lcsc.com/szlcsc/1811151442_WCH-Jiangsu-Qin-Heng-CH330N_C108996.pdf
Hackaday info about it: https://hackaday.io/project/162389-ch330n-33-usb-to-uart-info-and-applications
Translated datasheet: https://cdn.hackaday.io/files/1623896947650976/CH330DS1.zh-CN.en.pdf

I did a test with it and it works really well.
Baud rate of 115200 with the Parallax Serial Terminal Demo.spin loaded worked beautifully.
The only thing to note is that instead of DTR for reset, you need to use RTS.
But for a SOP8 package at around $3 + shipping or less, it's quite nice.

Breadboard of it is attached.
20191229_013632.jpg
3492 x 4656 - 5M

Comments

  • Cluso99Cluso99 Posts: 18,069
    For $4 I can use a real FT232RL.
    Or I can buy a complete CP2202 on a pcb for $1.30 shipped from Alicexxxx on eBay.
  • alatnetalatnet Posts: 80
    Well, for a crystal-less usb to serial sop8 chip that cost lest than $0.50 (link) that works with just two capacitors and 3v3, it's a pretty nice little chip that works out of the box with little setup.
    Good for designs that want to incorporate an on board usb to serial adapter for easy programming of a propeller.
  • AwesomeCronkAwesomeCronk Posts: 1,055
    (Off topic, sorry)

    What power board is on that pcb??
  • alatnetalatnet Posts: 80
    AwesomeCronk wrote: »
    (Off topic, sorry)

    What power board is on that pcb??

    MB102
    Specifically the Mini USB one (should be the last one in the dropdown).
    It works decently but the 5v converter chip gets hot if you put in more than 7 volts or so. Gets really hot if you stick a 12v supply to it. Though i dont think it can handle much in terms of amperage...
  • yetiyeti Posts: 818
    Does the CN330n have a unique serial number or can it be changed in some EEPROM?

    Because...
    —▷ http://hintshop.ludvig.co.nz/show/persistent-names-usb-serial-devices
  • alatnetalatnet Posts: 80
    I think? I cant really tell since im on windows.
  • jmgjmg Posts: 15,173
    alatnet wrote: »
    Well, for a crystal-less usb to serial sop8 chip that cost lest than $0.50 (link) that works with just two capacitors and 3v3, it's a pretty nice little chip that works out of the box with little setup.
    Good for designs that want to incorporate an on board usb to serial adapter for easy programming of a propeller.

    Yes, the So8 is simple to handle, and gives a good plain-vanilla solution for a simple, modest speed serial link.

    This thread has info on sped tests, and the CH3xx series are modest, showing starting to slow down sustained rates, above ~500k Baud
    https://www.eevblog.com/forum/microcontrollers/ch340-usb-uart-speed-tests/msg2528121/#msg2528121

    Many systems are fine with lower baud speeds.
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