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interfaces:ch340g [2015/02/22 02:52] darron [RS485] |
interfaces:ch340g [2021/08/11 11:08] (current) darron [Resources] |
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| ==== Nanjing QinHeng Electronics CH340 ==== | ==== Nanjing QinHeng Electronics CH340 ==== | ||
| <wrap right> | <wrap right> | ||
| - | {{: | + | {{: |
| \\ \\ | \\ \\ | ||
| - | {{: | + | {{: |
| - | \\ \\ | + | |
| - | {{: | + | |
| - | \\ \\ | + | |
| - | {{: | + | |
| </ | </ | ||
| Line 13: | Line 9: | ||
| These devices are becoming popular, so much so that fake ch340 chips exist. | These devices are becoming popular, so much so that fake ch340 chips exist. | ||
| - | The fakes have the ch340 USB identity | + | The fakes have the ch340 USB identity |
| + | (see below). | ||
| + | |||
| + | As well as being found on general purpose serial interfaces they are | ||
| + | often found on Arduino clones and ESP8266 bridges. | ||
| === Pinout === | === Pinout === | ||
| Line 31: | Line 31: | ||
| +------+ | +------+ | ||
| </ | </ | ||
| + | |||
| === Linux === | === Linux === | ||
| + | <wrap right> | ||
| + | {{: | ||
| + | </ | ||
| == Identity == | == Identity == | ||
| Line 52: | Line 56: | ||
| / | / | ||
| </ | </ | ||
| - | udev by-id is not supported by Pickle Microchip PIC ICSP. | + | |
| === Pickle Microchip PIC ICSP === | === Pickle Microchip PIC ICSP === | ||
| + | <wrap right> | ||
| + | {{: | ||
| + | </ | ||
| + | |||
| + | Pickle ICSP supports RS232 for programming boards such as the Velleman K8048 kit. | ||
| == Velleman K8048 Configuration == | == Velleman K8048 Configuration == | ||
| + | |||
| + | The K8048 kit has an RS232 interface which is used in a bit-bang mode of operation. USB UARTS | ||
| + | are not ideal for this purpose but can operate, albeit slowly. | ||
| + | |||
| + | The .pickle configuration for the CH340 is this. | ||
| < | < | ||
| - | DEVICE=/ | + | DEVICE=TTY |
| + | IFACE=/ | ||
| SLEEP=600 | SLEEP=600 | ||
| BITRULES=0x001F | BITRULES=0x001F | ||
| </ | </ | ||
| + | |||
| + | The SLEEP value affects both the speed of programming and the reliability of operation. | ||
| === RS485 === | === RS485 === | ||
| - | Cheap RS485 adapters exist using both this chip and a fake version of this chip (bottom picture above). | + | <wrap right> |
| + | {{: | ||
| + | \\ \\ | ||
| + | {{: | ||
| + | </ | ||
| + | |||
| + | Cheap RS485 adapters exist using both this chip and a fake version of this chip. | ||
| - | The real chip is a CH340G with 16 pins and the fake chip has 24 pins in an unmarked package. The top 20 pins of the fake match those of a genuine CH340R or CH340T device | + | The real chip is a CH340G with 16 pins and the fake chip has 24 pins in an unmarked package. The top 20 pins of the fake match those of a genuine CH340R or CH340T device |
| The RS485 I/O stage varies slightly between the real and fake adapters and is constructed like this for the CH340G device. | The RS485 I/O stage varies slightly between the real and fake adapters and is constructed like this for the CH340G device. | ||
| Line 73: | Line 96: | ||
| === Resources === | === Resources === | ||
| - | [[http:// | ||
| - | [[http:// | ||
| + | [[http:// | ||
| + | [[http:// | ||
