Post has attachment
MegaADK R3, USB Host Shield V2, with MAX3421E and second SPI device?

There are two versions of the R3 boards for sale which is quite confusing as they have different schematics: (I have one of each)

I tried UHS3 with the MegaADK R3 board and could not get the SS pin to change from 10 to 53. So the qc didnt work or any of the examples. I failed locating the solution to this. I switched to UHS2 library and I don't have to change anything in the library files or examples and it works (great job btw!).

I spent a while looking how to assign the SS and INT to alternative pins for a second SPI device but am only getting confused. At this webpage:
it indicates that you must modify UsbCore.h and MAX3421E.h. Is this correct?

I want to use interrupts for both SPI devices, is this possible/practical or do?

How does the SPI library get SS value? It looks to me that for the MegaADK board it is under variants (C:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\mega\pins_arduino.h).

For the MAX3421E I see SS redefined in UsbCore.h but don't see how that actually gets passed.

Bottom line, I think that I have to have the different device libraries modified to use alternate values (MAX3421 sticks with SS/INT as defined in the variants file) and SS1/INT1 for the second library that uses SPI.

Does this work then if each library instantiates its own SPI and executes SPI.begin and end?

AS you can see, some clarity would be greatly appreciated. New to Arduino but been bit banging for decades.


Hi, I want to use usb host shield to communicate with my slave arduino from master arduino. I know, that it is is possible by tx and rx pins but I want to try this for some other reason. So is it possible to achieve the following communication

master arduino....>> usb host shield.......>> slave arduino.

Also when I am attaching the shield on top of my arduino the Arduino IDE states that error uploading the code. when I remove the shield, then I can upload it successfully.. Why is it so??

Добрый день Олег.

Нашел ваше сообщение по поводу работы с BLDC мотором и контроллером A4963 (
Подскажите, перепробовал уйму вариантов запуска с различными настройками контроллера, но запустить чисто, без рывков и ошибок, так и не получается. Двигатель использую: GT2215/09 .

Заранее благодарю!

Hi There,

I had a question about the PTP library, I use a Nikon camera and wanted to try and use the library to control the camera, and obtain the filename of the most recently captured image.

I had a few questions if you don't mind,

1. With the most recent image, do I have to poll this after I capture an image or is it like an event driven thing where once an image is captured the PTP library can forward the image info?

2. I noted the PTP library supports exposure bracketing, when exposure bracketing is set up and enabled, do I call the PTP.capture command once and it does all three images, or do I have to call it three times, one for each bracket?

3. Is there any way to know through the PTP library when the camera has finished writing an image to the memory card, or the buffer is no longer full.

The main reason for number 3 is that instead of putting delays in my arduino code, it would be far more efficient if I could find out from the camera if it has finished taking the shot, one that is done I could move to the next position and take the next shot making the process as efficient as possible, with exposure bracketing, due to the bufferring issues this would become more important.

Not sure if I have explained myself well enough?

Post has attachment

Not sure if this is the right place to ask about the PTP library?

Post has attachment

Post has attachment

Post has attachment

I have a stepper motor controller which works through USB. The author states that it will work with any device which supports "USB Serial Port". It does work with Windows and Linux, using the standard USB serial port drivers. Will it work with USB Host for Arduino?
Wait while more posts are being loaded