connections: Restore write method.

This got removed when we upgraded the download and run protocol. This can be used to send data to the hub, until we support full hub-to-hub communication.

pybricks/support#376

Also update the notebook demo while we are at it. This removes the USB example for SPIKE.

Author: laurensvalk

demo/runner.ipynb

@@ -2,83 +2,113 @@
  "cells": [
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 1,
    "metadata": {},
    "outputs": [],
    "source": [
-    "from pybricksdev.connections import EV3Connection, BLEPUPConnection, USBPUPConnection\n",
-    "from pybricksdev.ble import find_device\n",
-    "from asyncio import gather\n",
-    "import logging\n",
-    "\n",
-    "logging.basicConfig(format='%(asctime)s: %(levelname)7s: %(message)s', level=logging.DEBUG)"
+    "from pybricksdev.connections import PybricksHub\n",
+    "from pybricksdev.ble import find_device, nus\n",
+    "from asyncio import gather, sleep\n",
+    "import logging"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 2,
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Searching for Pybricks Hub\n"
+     ]
+    }
+   ],
    "source": [
-    "# Go to help > Edit Keyboard Shortcuts to bind \"run all cells\" to your favorite key.\n",
-    "# This way you can easily run all cells again without resetting the kernel.\n",
-    "# That way, your hubs stay connected so that programs runs quickly.\n",
-    "\n",
-    "try:\n",
-    "    ev3, hub, spike\n",
-    "except:\n",
-    "    spike = USBPUPConnection()\n",
-    "    await spike.connect('Pybricks Hub')\n",
-    "    \n",
-    "    ev3 = EV3Connection()\n",
-    "    await ev3.connect('192.168.133.101')\n",
-    "    \n",
-    "    hub = BLEPUPConnection()\n",
-    "    address = await find_device('Pybricks Hub')\n",
-    "    await hub.connect(address)\n",
-    "    \n"
+    "hub = PybricksHub()\n",
+    "address = await find_device('Pybricks Hub')\n",
+    "await hub.connect(address)   \n"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 3,
    "metadata": {},
-   "outputs": [],
-   "source": [
-    "%%file _ev3.py\n",
-    "\n",
-    "print(\"hi from ev3\")"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Overwriting _pup.py\n"
+     ]
+    }
+   ],
    "source": [
     "%%file _pup.py\n",
     "\n",
-    "print(\"hi from control+\")\n"
+    "from usys import stdin\n",
+    "from uselect import poll\n",
+    "\n",
+    "# Register the standard input so we can read keyboard presses.\n",
+    "keyboard = poll()\n",
+    "keyboard.register(stdin)\n",
+    "\n",
+    "while True:\n",
+    "    # Check if a key has been pressed.\n",
+    "    if keyboard.poll(0):\n",
+    "\n",
+    "        # Read the key and print it.\n",
+    "        key = stdin.read(1)\n",
+    "        print(\"You pressed:\", key)\n"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 4,
    "metadata": {},
    "outputs": [],
    "source": [
-    "%%file _spike.py\n",
-    "\n",
-    "print(\"hi from spike\")\n"
+    "async def send_data(hub):\n",
+    "    \n",
+    "    await sleep(1)\n",
+    "    await hub.client.write_gatt_char(nus.NUS_RX_UUID, bytearray(b\"HELLO!\"), True)"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "data": {
+      "application/vnd.jupyter.widget-view+json": {
+       "model_id": "c2d6d75f92d34d28a718b35ae4d08a29",
+       "version_major": 2,
+       "version_minor": 0
+      },
+      "text/plain": [
+       "  0%|          | 0.00/156 [00:00<?, ?B/s]"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "You pressed: H\n",
+      "You pressed: E\n",
+      "You pressed: L\n",
+      "You pressed: L\n",
+      "You pressed: O\n",
+      "You pressed: !\n"
+     ]
+    }
+   ],
    "source": [
-    "await gather(hub.run('_pup.py'), spike.run('_spike.py'), ev3.run('_ev3.py'))"
+    "result = await gather(hub.run('_pup.py'), send_data(hub))"
    ]
   },
   {
@@ -87,10 +117,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# await ev3.get('_ev3.py')\n",
-    "# await hub.disconnect()\n",
-    "# await spike.disconnect()\n",
-    "# await ev3.disconnect()"
+    "await hub.disconnect()"
    ]
   }
  ],
@@ -115,4 +142,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 4
-}
+}

pybricksdev/connections.py

@@ -757,6 +757,9 @@ async def send_block(self, data):
             self.expected_checksum = -1
             raise
 
+    async def write(self, data, with_response=False):
+        await self.client.write_gatt_char(NUS_RX_UUID, bytearray(data), with_response)
+
     async def run(self, py_path, wait=True, print_output=True):
 
         # Reset output buffer