Merge pull request #1153 from ARMmbed/hk-update-usbhid-snippets

Update USBHID snippet as  API as changed

Author: Amanda Butler

docs/api/usb/USBHID.md

@@ -12,44 +12,49 @@ You can use the USBHID class to turn an Mbed board into an HID (Human Interface
 
 ### main.cpp   
 
-```C++ TODO
-#include "mbed.h"
-#include "USBHID.h"
-
-//We declare a USBHID device. By default input and output reports are 64 bytes long.
-USBHID hid(true, 8, 8);
+```C++
+#include <stdio.h>
 
-Serial pc(USBTX, USBRX);
+#include "mbed.h"
+#include "drivers/USBHID.h"
 
-//This report will contain data to be sent
-HID_REPORT send_report;
-HID_REPORT recv_report;
+// Declare a USBHID device
+USBHID HID(8, 8, 0x1234, 0x0006, 0x0001, true);
 
-DigitalOut l1(LED1);
+HID_REPORT output_report = {
+    .length = 8,
+    .data = {0}
+};
+HID_REPORT input_report = {
+    .length = 0,
+    .data = {0}
+};
 
-int main(void) {
-    send_report.length = 8;
+DigitalOut led_out(LED1);
 
+int main(void)
+{
     while (1) {
 
-        //Fill the report
-        for (int i = 0; i < send_report.length; i++)
-            send_report.data[i] = rand() & 0xff;
+        // Fill the report
+        for (int i = 0; i < output_report.length; i++) {
+            output_report.data[i] = rand() & UINT8_MAX;
+        }
 
-        //Send the report
-        hid.send(&send_report);
+        // Send the report
+        HID.send(&output_report);
 
-        //try to read a msg
-        if(hid.read_nb(&recv_report)) {
-            l1 = !l1;
-            for(int i = 0; i < recv_report.length; i++) {
-                pc.printf("%d ", recv_report.data[i]);
+        // Try to read a msg
+        if (HID.read_nb(&input_report)) {
+            led_out = !led_out;
+            for (int i = 0; i < input_report.length; i++) {
+                printf("%d ", input_report.data[i]);
             }
-            pc.printf("\r\n");
+            printf("\r\n");
         }
     }
 }
-```   
+```
 
 ### USBHID.py   
 
@@ -61,38 +66,33 @@ from pywinusb import hid
 # Whenever the host computer receives data from the
 # Mbed board, the received data is printed
 def on_data(data):
-    print("Got message %s" % data)
+    print(f"Got message {data}")
 
 '''
 Gets all HIDs currently connected to host computer,
 and sets the first device with string "mbed" in its
 vendor name equal to variable mbed. This variable
 will be used to send data to the Mbed board.
 '''
-all_devices = hid.find_all_hid_devices()
-mbeds = [dev for dev in all_devices if dev.vendor_name.find("mbed") >= 0]
-if len(mbeds) == 0:
-    print("No HID devices found")
-    exit(-1)
-mbed = mbeds[0]
-
-# Sends 8 bytes of data to the Mbed board
-# The Mbed board should receive the data "1 2 3 4 5 6 7 8"
-mbed.open()
-mbed.set_raw_data_handler(on_data)
-message = bytearray(9)
-message[1] = 1
-message[2] = 2
-message[3] = 3
-message[4] = 4
-message[5] = 5
-message[6] = 6
-message[7] = 7
-message[8] = 8
-
-mbed.find_output_reports()[0].send(message)
-
-```   
+all_hid_devices = hid.find_all_hid_devices()
+mbed_devices = [d for d in all_hid_devices if "mbed" in d.vendor_name]
+
+if mbed_devices is None:
+    raise ValueError("No HID devices found")
+
+# A buffer of bytes representing the values 1-8
+# The first byte is the report ID which must be 0
+buffer = [0, 1, 2, 3, 4, 5, 6, 7, 8]
+
+mbed_devices[0].open()
+# Set custom raw data handler
+mbed_devices[0].set_raw_data_handler(on_data)
+
+# Send the message to the Mbed board
+out_report = mbed_devices[0].find_output_reports()
+out_report[0].set_raw_data(buffer)
+out_report[0].send()
+```
 
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