I am making a USB keyboard using stm32F0RBT6 micro-controller. I want to receive data from PC for Caps Lock and Scroll Lock leds. Do I need to initiate a callback funtion like those ones?
static uint8_t USBD_HID_EP0_RxReady (USBD_HandleTypeDef *pdev);
static uint8_t USBD_HID_DataOut (USBD_HandleTypeDef *pdev, uint8_t epnum);
Any help regarding receiving data would be appreciated. Thank you.
A USB keyboard uses the USB class HID (Human Interface Device), the specification can be found here. The state of the LEDs are set with a set_report message, which is transmitted over the setup endpoint (also called default endpoint in the document) which is also endpoint 0 (EP0).
The format of the report used for keyboards can be found in the specification (page 59).
Therefore you need to use the callback function USBD_HID_EP0_RxReady and parse the set_report message you received.
Related
I'm new to openthread and got a minimal Thread network running on two Makerdiary USB dongles based on nRF52840. Now I'd like to intercept special IEEE 802.15.4 frames and process them separately, e.g. from an energy harvesting switch. The MAC header looks like this:
Frame Control: 0x0801 (use short addresses)
Sequene Number: 1 byte
Address field: 0xffffffff (short destination address and pan id)
Source address and pan id are not included
How do I install a callback to intercept these frames and pass all others on to openthread?
Thanks
One way is to hook into the nRF52840 radio driver where radio frames are received and passed to OpenThread.
I am currently learning CMSIS-RTOS v2 and I have an issue that is bugging me and I can't find the answer I need.
I am using the STM32L476-Disco board and the joystick center button as an interrupt. I have a very simple Interrupt callback for my center joystick interrupt :
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin){
//osEventFlagsSet(evt_id,0x0001);
HAL_GPIO_TogglePin(LD5_GPIO_Port,LD5_Pin);
osThreadFlagsSet(ThId_Led_Blink,0x0001);
}
When I call osThreadFlagsSet, the microcontroller freezes and nothing else happen. This is why I've put the HAL_GPIO_TogglePin : to see if the mcu was still responding or not.
I know that my interrupt resets correctly because when I only put my pin toggle, I can toggle the Led correctly.
ThId_Led_Blink is a ThreadId
osThreadId ThId_Led_Blink;
I've checked that the ID is set correctly in my debugger and it is (it's not null).
As you can see, I've tried with osEvenFlagsSet and I have the same result.
When I check the CMSIS_RTOS v2 documentation, it does specify that osThreadFlagsSet can be called from an ISR, but I am not sure if I need to do something else in that case for the Flags to be set correctly and resolve the issue when the ISR is hanging.
Thanks for your help
So after frustrating hours of searching, I finally fixed my issue.
As described in this website : https://www.freertos.org/RTOS-Cortex-M3-M4.html, for STM32 microprocessor, you need to set the NVIC Group Priority to 4. If you look on freeRTOS, they are talking about putting this line in your code :
NVIC_PriorityGroupConfig( NVIC_PriorityGroup_4 );
However, the STM32 has it's own library for the NVIC and the correct function to set the priority group is :
HAL_NVIC_SetPriorityGrouping(4);
Why go with the same name when you can change everything?
So make sure to call this function before your kernel initialization if you are using nested interrupts with FreeRTOS/CMSIS RTOS.
Also, make sure that your nested interrupt priority is in the range of configured interrupt priority for your FreeRTOS, otherwise, the osThreadFlagsSet function will fail automatically.
i am working on a project in msp430f2274 microcontroller. In my project i am trying to read an reed switch which is being connected to a GPIO pin at P2.3. Normally the pin will remain HIGH as it is being connected to pull up from the hardware. when once the switch is pressed/activated a LOW will come and it will trigger the Hardware. till here it is working fine. but now i want to read the other interrupt also, when it goes back to high. I have tried the interrupt type from low - high to high -low in ISR but still no efffect. please help.
i have added ISR from the code
static char x=0;
#pragma vector=PORT1_VECTOR
__interrupt void PORT1_ISR(void)
{
P1IES^=BIT2;
P1OUT^=(BIT0); // enrer the rest code for detection of door open or close.
P1IFG &= ~BIT2;
//P1IES&=~BIT2;
__bis_SR_register_on_exit(GIE+LPM0_bits); // Enter LPM3 on ISR exit
}
Just an idea, sry if this doesn't help.
You could use a timer that starts with the button click and triggers an interrupt when the button is released.
I have been using the mouse sketch at the bottom of this message (written by someone else) to try to get the motion data out of a PS/2 mouse. I have checked the specification for this mouse which says that it is PS/2 compatible. However, when I run it it appears to stop at the first line of mouse_init where it says, "mouse.write(0xff); // reset". This is a call to a function in ps2.h. ps2.h has been around since 2008 and has been used in a number of projects, so I assume it is okay, but I was wondering if there might be some peculiar features of USB mice connecting as PS/2 mice that this library was never designed to cope with. Does anyone have any experience that might shed some light on this?
I have been able to determine that mouse.write is changing the state of my Genius mouse, but it gets stuck at the point where the Mouse is supposed to bring the clock state low so that the host can proceed to transmit data. Before mouse.write starts the clock state is low, but it gets pushed high by the host a few lines into mouse.write and stays there. The mouse never pulls it low again. Any thoughts on what the trouble might be would be greatly appreciated.
#include <ps2.h>
/*
* an arduino sketch to interface with a ps/2 mouse.
* Also uses serial protocol to talk back to the host
* and report what it finds.
*/
/*
* Pin 5 is the mouse data pin, pin 6 is the clock pin
* Feel free to use whatever pins are convenient.
*/
PS2 mouse(6, 5);
/*
* initialize the mouse. Reset it, and place it into remote
* mode, so we can get the encoder data on demand.
*/
void mouse_init()
{
mouse.write(0xff); // reset
mouse.read(); // ack byte
mouse.read(); // blank */
mouse.read(); // blank */
mouse.write(0xf0); // remote mode
mouse.read(); // ack
delayMicroseconds(100);
}
void setup()
{
Serial.begin(9600);
mouse_init();
}
/*
* get a reading from the mouse and report it back to the
* host via the serial line.
*/
void loop()
{
char mstat;
char mx;
char my;
/* get a reading from the mouse */
mouse.write(0xeb); // give me data!
mouse.read(); // ignore ack
mstat = mouse.read();
mx = mouse.read();
my = mouse.read();
/* send the data back up */
Serial.print(mstat, BIN);
Serial.print("\tX=");
Serial.print(mx, DEC);
Serial.print("\tY=");
Serial.print(my, DEC);
Serial.println();
// delay(20); /* twiddle */
}
Solved it. As it turns out the Genius mouse I brought is not backward compatible with PS/2 even though the specification says it is. They must have exchanged the sensor chip for one where the PS/2 capability was not present at some point. I now have another USB mouse which is doing the job I wanted perfectly.
I'm currently developing an application on 10.6.7 which should receive notifications when a new usb device is plugged in. I found out that there is a IOKit function which handles such stuff 'IOServiceAddMatchingNotification'. Because the return value from this specific function is 0, I think that the problem perhaps is in my matching Dictionary, which is given into this function. I declare the Dictionary that way:
CFMutableDictionaryRef matchingDict = IOServiceMatching(kIOUSBDeviceClassName);
Because I wan't to receive a notification for each device, I don't know if this is the right way to create this particular dictionary.
My complete code look like this:
ioKitNotificationPort = IONotificationPortCreate(kIOMasterPortDefault);
notificationRunLoopSource = IONotificationPortGetRunLoopSource(ioKitNotificationPort);
CFRunLoopAddSource(CFRunLoopGetCurrent(), notificationRunLoopSource, kCFRunLoopDefaultMode);
CFMutableDictionaryRef matchingDict = IOServiceMatching(kIOUSBDeviceClassName);
addMatchingNotificationResult = IOServiceAddMatchingNotification(ioKitNotificationPort,
kIOPublishNotification,
matchingDict,
deviceAdded,
NULL,
Does anyone has a idea why this won't work?
(Note: The Callback function is a static void c function and the rest is wrapped ins
ide a Obj-C class).
Thanks
Xcode 4, 10.6.7
Weirdly, you must empty the iterator returned by IOServiceAddMatchingNotification before the notification will be armed. I don't see that in the code provided, so that could be in the issue. That iterator is actually what you need to keep around to keep the notification running.
io_iterator_t ioNotification;
addMatchingNotificationResult = IOServiceAddMatchingNotification(ioKitNotificationPort,
kIOPublishNotification,
matchingDict,
deviceAdded,
NULL,
&ioNotification);
while ((service = IOIteratorNext(ioNotification)))
{
NSLog(#"Hey, I found a service!");
IOObjectRelease(service); // yes, you have to release this
}
In my opinion, u should download the source code form IOUSBFamily on opensource.apple.com, and then find the code for USB Prober, this application does exactly the same thing as u described, listening the USB Device attachment.(Further, USB Prober also get the general device and configuration descriptor, maybe it is also the things u need.)
Did you add the VID and PID of the device you wish to look for to your matching dictionary? For the dictionary you have, and VID= yourVid, PID= yourPid, it would be:
CFDictionaryAddValue(matchingDict, usbVendorId, yourVid);
CFDictionaryAddValue(matchingDict, usbProductId, yourPid);
Another thing - after the call to IOServiceAddMatchingNotification succeeds, you need to call your device-added handler with the iterator that was set in the call. That will arm the notification and check for existing devices.
the easiest way to do what i think you are describing is to hook into the DiskArbitration Framework. DA is relatively new to OSX and allows userland applications to examine devices as they get attached. it is what is used to open iTunes when an iPod is attached, launch iPhoto when a camera is attached, etc... if the USB device you are looking for is a storage device then this will work for you. otherwise you will need to go the matching dictionary route...