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I have brought a USB HOST Mini a few years ago. It’s really cheap (29.5 Yuan/$4.6964). But there is no document for it and very hard to use. And I began to study it this month. At last, I make a covert board for it. You can use it with Teensy 3.2. Before start, we should know below things: 1. All the pins use on this USB Host Mini is 3.3V, it can be connected to Teensy directly(and don’t do it on your Arduino Micro Pro which is 5v) 2. You should know the difference between original board [pic1] and Chinese version[pic2], I have marked in red and green cycles. I think that’s the only difference between them. Pic1 Pic2
3. Before using the USB Host Shield you have to make some rework on it. 3.1 cut the wire in the red circle. Reason：it’s the power pin for USB device. And if we don’t cut it, the USB device will only get 3.3v. We cut the wire and send 5V power from outside(green in the below picture) 3.2 Connect the reset pin directly to the 3.3v pin. In this way, reset pin is always high.
4. The pin on this board is as below. DON’T trust the pins naming on backward board side[ref:1] 5. I think there is something wrong with SPI4Teensy Library. Please make changes in \libraries\USB_Host_Shield_2.0-master\settings.h to disable SPI4Teensy Lib #if defined(CORE_TEENSY) && defined(KINETISK) //move this #define USING_SPI4TEENSY3 USE_SPI4TEENSY3 #else #define USING_SPI4TEENSY3 0 #endif //Add++ #define USING_SPI4TEENSY3 0 //Add++
I have make a simple table for Teensy to UHS connections. You can connect them directly. Teensy UHS GND GND D13 SCK D12 MISO D11 MOSI D10 SS D9 INT VIN 5V It’s for USB device. 3.3V MAX_RST As you can see, I have connect 3.3V to the MAX_RST on the board, but I don’t know why it’s not work (too thin?). That’s the reason why you should make 3.2 rework. PCB: Schematic:
Note：as you can see, I have connected the Reset Pin of UHS to 3.3V, but I don’t know why UHS doesn’t. But after I connect theses pin with a wire, it works well. Teensy is much faster than Adruino.
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发表于 2018-8-25 15:17
楼主