add rpi touchpad notebook

boards/Pynq-Z2/base/notebooks/rpi/rpi_touchpad.ipynb

+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Reading Values from Touch Keypad\n",
+    "\n",
+    "This demonstration shows how to interact with the Raspberry Pi Touch Keypad.\n",
+    "The Raspberry Pi Touch Keypad is required (https://www.seeedstudio.com/Raspberry-Pi-Touch-Keypad-p-2772.html).\n",
+    "\n",
+    "![](data/rpi_touchpad.jpg)\n",
+    "\n",
+    "The Raspberry Pi touch keypad supports up to 16 keys with adjustable \n",
+    "sensitivity and built-in LD0.\n",
+    "Touch keypad is read only, and has IIC interface\n",
+    "connected to SDA1 and SCL1 on the Raspberry Pi interface.\n",
+    "The I2C will read 2 bytes of data: `Data_0` and `Data_1`.\n",
+    "* `Data_0`: B7 ~ B0 is TP0 ~ TP7 on/off status. 0 is key off, 1 is key on.\n",
+    "* `Data_1`: B7 ~ B0 is TP8 ~ TP15 on/off status. 0 is key off, 1 is key on.\n",
+    "\n",
+    "### 1. Prepare the overlay\n",
+    "Download the overlay first, then select the shared pin to be connected to\n",
+    "RPI header (by default, the pins will be connected to PMODA instead)."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "application/javascript": [
+       "\n",
+       "require(['notebook/js/codecell'], function(codecell) {\n",
+       "  codecell.CodeCell.options_default.highlight_modes[\n",
+       "      'magic_text/x-csrc'] = {'reg':[/^%%microblaze/]};\n",
+       "  Jupyter.notebook.events.one('kernel_ready.Kernel', function(){\n",
+       "      Jupyter.notebook.get_cells().map(function(cell){\n",
+       "          if (cell.cell_type == 'code'){ cell.auto_highlight(); } }) ;\n",
+       "  });\n",
+       "});\n"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    }
+   ],
+   "source": [
+    "from pynq.overlays.base import BaseOverlay\n",
+    "\n",
+    "base = BaseOverlay(\"base.bit\")\n",
+    "base.select_rpi()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### 2. Instantiate the Microblaze\n",
+    "The Microblaze will control the pins on the RASPBERRYPI header."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "%%microblaze base.RPI\n",
+    "\n",
+    "#include \"xio_switch.h\"\n",
+    "#include \"circular_buffer.h\"\n",
+    "#include \"i2c.h\"\n",
+    "\n",
+    "// Device constants\n",
+    "#define TOUCHPAD_DEV_ADDRESS         0x57\n",
+    "\n",
+    "unsigned int get_touchpad_reg_value(){\n",
+    "    uint8_t data[2];\n",
+    "    i2c device = i2c_open_device(1);\n",
+    "    set_pin(2, SDA1);\n",
+    "    set_pin(3, SCL1);\n",
+    "    i2c_read(device, TOUCHPAD_DEV_ADDRESS, data, 2);\n",
+    "    return (unsigned int) ((data[0] << 8) + data[1]);\n",
+    "}"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### 3. Read the key values\n",
+    "The available pin names are listed below."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "PIN_MAPPING = {'circle': 0,\n",
+    "               'cross': 1,\n",
+    "               'square': 2,\n",
+    "               'r': 3,\n",
+    "               'home': 4,\n",
+    "               '+': 5,\n",
+    "               '-': 6,\n",
+    "               'l': 7,\n",
+    "               'down': 8,\n",
+    "               'right': 9,\n",
+    "               'up': 10,\n",
+    "               'left': 11,\n",
+    "               'power': 12,\n",
+    "               'rpi': 13,\n",
+    "               'logo': 14,\n",
+    "               'triangle': 15\n",
+    "               }"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "To convert the raw data into the value for each key, we define the following\n",
+    "functions."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def reg2int(reg_value, key_number):\n",
+    "    return \"{0:b}\".format(reg_value).zfill(16)[-(key_number+1)]\n",
+    "\n",
+    "def get_touchpad(key_name):\n",
+    "    reg_value = get_touchpad_reg_value()\n",
+    "    key_number = PIN_MAPPING[key_name]\n",
+    "    return reg2int(reg_value, key_number)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Run the following code without pressing any button."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'0'"
+      ]
+     },
+     "execution_count": 5,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "get_touchpad('home')"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "While pressing gently on the home button of the touch keypad, run the following code."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'1'"
+      ]
+     },
+     "execution_count": 6,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "get_touchpad('home')"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "While pressing the right arrow and square at the same time, \n",
+    "run the following code. Note that there are 2 read commands issued,\n",
+    "although 1 read command can get values for all the keys."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Key right reads value 1.\n",
+      "Key square reads value 1.\n"
+     ]
+    }
+   ],
+   "source": [
+    "for key in ['right', 'square']:\n",
+    "    print('Key {} reads value {}.'.format(key, get_touchpad(key)))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### 4. Cleanup\n",
+    "Switch back the connection on the shared pin to PMODA header."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "base.select_pmoda()"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.6.0"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 1
+}