Timeline for Raw mode control of USB device via TTL
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 21, 2022 at 7:59 | comment | added | Justme | @Francesco Yes, that's an USB host chip. But like I said in my first comment, that chip alone is more expensive than a MCU with built-in USB host. If you want to pay for a non-USB MCU and the USB host chip, by all means. Then you need to develop drivers for the USB host chip and then drivers how to use CH340 through the USB host chip drivers. That means writing generic CDC drivers or CH340 specific drivers, so drivers anyway. | |
| Sep 21, 2022 at 7:43 | comment | added | Francesco | MAX3421E here you go.... | |
| Sep 21, 2022 at 7:39 | comment | added | Justme | Well, you can try to find how many bit-bang USB host implementations exist, and how many of them are actually usable, to see why "it's just voltage signal levels" is a gross understatement. And if you say CH340 is a CDC device instead of custom device, why I only find info it's not a CDC device and that's why it needs custom drivers? | |
| Sep 21, 2022 at 7:24 | comment | added | Francesco | @Justme This does not convince me. How is it possible that a USB host functionality cannot be "emulated"? After all it is just voltage signal levels. Moreover, this is a bare USB CDC which actually does not need a real "driver" but only an inf file with a signature id. | |
| Sep 21, 2022 at 5:40 | comment | added | Justme | @Francesco You don't seem to understand how USB or how "simple" USB serial chips or devices work. You need to know what to communicate with the CH340 chip to make it do what you want. Just like you need drivers to communicate with USB CDC or USB storage devices, you need drivers to communicate with CH340. And USB host can't really be emulated, you need an actual MCU with actual USB host. | |
| Sep 21, 2022 at 5:17 | comment | added | Francesco | @Justme Nope. I do not need drivers. It is just a simple serial interface. That's why I wrote "raw mode" communication. Even far more complex devices, such as printers, can be interfaced in raw mode. Thus, the USB host functionality is the only thing that I am missing. Any idea how to emulate that? | |
| Sep 20, 2022 at 21:26 | answer | added | jonathanjo | timeline score: 2 | |
| Sep 20, 2022 at 21:02 | comment | added | Dejvid_no1 | I agree with Justme. The cheapest you can get away with (time and cost wise) is probaby a Raspberry Pi or similar. | |
| Sep 20, 2022 at 20:58 | comment | added | Justme | You need anything with USB host and drivers for CH340. You will need to spend much more than a budget microcontroller anyway so you might as well use something that can directly communicate with it, such as a cheap Windows PC or single board computer that runs Linux. But any MCU with USB host will do, as long as you can write drivers for CH340. | |
| Sep 20, 2022 at 20:37 | history | asked | Francesco | CC BY-SA 4.0 |