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Home Automation Home Automation has been the “next big thing” for quite a while now. But – with not too many exceptions – it remains the next big thing! Sure, there are people who have adopted Home Automation to some degree. And there are quite a few Home Automation specialist businesses set up to drag customers into the 21st century (kicking and screaming, we ask?). Well, with the new “Inventa” Home Automation Maker Plates from Altronics, that just might be about to take that giant leap forward for all mankind! L et’s face it: despite all of its promise, Home Automation hasn’t exactly set the world on fire – yet! Yes, we’ve all heard of the family whose house “does everything”, whether they’re home or not, but that’s the exception. Despite the obvious advantages of returning home to a beautifully cool (or warm) house, with the dinner in the oven ready to serve, the security system going on standby after protecting the home all day . . . you get the picture, we’re sure. We believe that a major, perhaps the major reason for Home Automation’s lack of penetration is that unless you are building a new home and can accommodate the extra cabling, extra sensors and control circuitry, it’s all just too hard for the average person to get their mind around, let alone actually do. We’re also pretty sure that there would be a fair number of people, especially hobbyists and even more especially SILICON CHIP readers, who would like to have a go at Home Automation – if only it could be made simpler. Enter Altronics . . . and their “Inventa” range professionals will even want to use them! In addition to looking good, they’re quite powerful too. The two we’re describing in this article (of the three they offer) are designed to fit into a standard Australian electrical wallplate, as might be used for a power outlet or light switch. They are the K9660 Inventa 2.8in TFT Touchscreen Maker Plate and the K9655 Inventa 16x2 LCD Shield Maker Plate. Both come with a pair of wallplate covers (two different styles) and standard mounting hardware. They also have headers at the back of the wallplate which can accept standard Arduino shields. Incidentally, if all this is new to you, ‘shield’ is Arduino terminology for an add-on board with a specific pinout What to use them for? The most obvious use for these Maker Plates is to create a user interface for a home automation system, allowing information to be displayed on their screens as well as accepting input via either the keypad or touch panel. As mentioned above, “Home automation” refers to systems that control home lighting, blinds and shutters, air conditioning/ventilation appliances and so on – anything electrical that’s found in the home. Features & Specifications Model: TFT Touchscreen Maker Plate (K9660) LCD Shield Maker Plate (K9655) User Interface: 2.8in colour LCD touchscreen 16x2 character LCD with 9-key keypad Processor: SAM3X8E (ARM Cortex M3) ATmega328P Due Duemilanove Arduino compatibility: The Inventa series is a range of Arduino-compatible “Maker Plates” which make an easy way of adding a slick-looking user interface to a DIY home automation project. They have been designed and produced in Australia by Altronics. We reckon they look so good that that allows it to directly piggy-back onto a main controller board, or even another shield underneath it. It’s actually the Arduino which does all the sensing, controlling and actuating and communicating –these Maker Plates are the information “interface” between the Arduino and you! Flash memory: 512kB RAM: 30kB (2kB reserved for bootloader) 96kB 2kB 32-bit, 84MHz 8-bit, 16MHz I/O pin voltage: 3.3V 5V Other features: Switchmode DC regulator Buzzer, two relays Processor speed: Review/Tutorial by Tim Blythman 76 Silicon Chip Australia’s electronics magazine siliconchip.com.au Made Easy(ish!) (Left): The Inventa Touchscreen Maker Plate (K9660) is supplied mostly pre-assembled. The pre-loaded demo sketch for the TFT Touchscreen Maker Plate shows a splash screen with the Altronics logo. Such graphics are well suited to the colour screen and the powerful SAM3X8E microcontroller, which has 512kB of flash memory, useful for storing icons and other graphics. (Right): Conversely, the Inventa LCD Shield Maker Plate (K9655) must be assembled. It is based on an ATmega328P processor and has a 16x2 display with nine pushbuttons for user control (yes, believe us – there are nine!). The interface for the LCD Shield Maker Plate reminds us of a home security alarm panel, and it would be well suited to such a role. The demo sketch shows off most of the hardware features that are built into the board. (See the panel at the end of this article, Just what does “Home Automation” mean?). The use of standard wallplate hardware means installing them on a wall or cabinet is very easy. These Maker Plates could also be used to add a user interface panel to an equipment enclosure, without having to worry about custom bezels and mounting. They are also both fully-fledged microcontroller systems; both are fully compatible with the Arduino IDE (integrated development environment), and both are capable of being programmed to perform a variety of tasks. Many standard shield-format boards can be plugged directly into the PCB to add extra functions. This could be as simple as putting some relays on a shield breakout board to automate light switching (but you’d need to be very careful to ensure safe isolation and spacing if those relays are going to switch mains!). Or you could plug in a digital radio transmitter, Bluetooth or WiFi shield to communicate with and interface to remote devices. That would be safer as it would allow you to keep full mains isolation. siliconchip.com.au An Ethernet shield which supports power-over-Ethernet (PoE) would also be a useful addition, providing a connection into a LAN as well as power. We’ll look at the K9660 first. It also has a SAM3X8E 32-bit microcontroller, which can run at up to 84MHz. That makes it substantially more potent than your typical Arduino. It’s compatible with the Arduino Due. Kit #1: Touchscreen Maker Plate (K9660) Circuit description While pitched as a kit, this Maker Plate does not require much assembly. In fact, by merely connecting the LCD to the main PCB, you’re already in a position to load and test the supplied demonstration code. The reason that the TFT Touchscreen Maker Plate does not require much assembly is that most of the components are SMDs and they come pre-soldered. There are a handful of through-hole parts that need to be fitted, but the bulk of the assembly is actually fitting the mechanical parts of the plate together. There are several photos, circuit diagrams and overlays provided in the kit to assist construction, but in this article, we’ll describe what you need to know to get it up and running. The K9660 has a 2.8in touchscreen LCD (very similar to the 2.8in LCDs that we use on our Micromite projects) with an ILI9341 controller. Australia’s electronics magazine The circuit of the K9660 main board is shown overleaf in Fig.1. You will notice that it’s dominated by the 144pin microcontroller (IC1) and the 2.8inch LCD touchscreen, which attaches via a 50-pin ‘flat flexible’ cable. PWM backlighting control is enabled by NPN transistor Q1. This micro has an internal USB interface, and this is wired up to CON2, a micro-USB (Type B) socket. In addition to two 39Ω impedance-matching resistors for the D- and D+ lines, there are three varistors to protect the micro from static electricity, on the D-, D+ and USBID lines (V1-V3). Power is fed in either via USB socket CON2 (through diode D1 and jumper JP1) or via terminal block CON3 and reverse polarity protection diode D4. The 5V rail powers the touchscreen backlight and also goes to the 5V pin on the shield connector. 5V is also fed to the 3.3V regulator, REG2, which October 2019  77 D3 SS14 A K CON3 1 + VIN K A REG2 MC 33375ST-3.3 REG1 R-78E5.0-0.5 D4 SS14 +5V OUT IN 1 2 – 2 47 F 10 F GND 35V 10V 10 F 10V IN OUT +3.3V 3 ON /OFF GND 10 F 10V 4 JP1 0 D1 SS14 A D2 SS14 100nF K L3 25 H 56 5x100nF 61 10V  0.5A 10 45 10 F 100nF PS1 104 124 34 AREF 75 CON2 USB MICRO-B 39 1 2 3 X 4 38 39 V1 5V 6.8k IOREF 43 37 39 22pF V2 5V SHLD B 42 40 50 100k 53 13 RST 14 3.3V 129 5V ERASE V3 5V GND GND 10 F 100nF 100nF A K VIN 16 130 JP3 NRST 69 47 78 SHLD A 79 A0 80 A1 81 A2 82 A3 83 A4 49 A5 48 35 RST S1 100nF X1 12MHz 22pF 22pF 36 100nF A 10V LED1 57 VDD IN 41 VDD UTMI VDDOUT 100nF 100 10 F 10V 73 VDDANA 100nF L1 25 H 100nF L2 25 H 100nF 100nF +3.3V USB IN 11 VDD IO 62 VDD IO 105 VDD IO 125 VDD IO 52 VDD BU 1 PB26 3 PA10 4 PA11 5 PA12 6 PA13 7 PA14 8 PA15 23 PA0 24 PA1 55 PC1 108 PA25/MISO 109 PA26/MOSI 64 PC6 110 PA27 63 PC5 VDDCORE VDDCORE VDDCORE VDDCORE VDDCORE VDDPLL ADVREF VBUS DHSDM DFSDM DHSDP DFSDP VBG IC1 ATSAM3X8EA-AU SHDN FWUP PC7 PD0 PC8 (MANY UNUSED PINS NOT SHOWN) PD1 PB11 PA18 PA17 PD3 PB27 PC0 PD8 NRST PD7 NRSTB PA28 PA16 PC21 PA24 PC22 PA23 PC4 PA22 PC23 PA6 PC24 PA4 PC25 XOUT32 PC26 XIN32 PC27 XOUT PA25 PA9 XIN JTAGSEL 46 TST 51 GND 12 GND 58 GND 106 GND 126 GND PLL GND UTMI GND BU GND ANA 33 44 54 74 PA8  K 65 66 70 9 68 21 20 111 132 133 116 134 135 136 137 139 144 2 27 1k SC 20 1 9 78 ALTRONICS K9660 ARDUINO (ARM) TOUCHSCREEN WALLPLATE Silicon Chip Australia’s electronics magazine siliconchip.com.au 2.8-INCH TOUCHSCREEN LCD PANEL WITH LED BACKLIGHTING, ILI9341 CONTROLLER +5V 4x 15 R-78E 5.0-0.5 IN OUT GND +3.3V TAB (GND) Y+ X– Y– GND GND GND IN OUT ON/OFF 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 33 44 45 35 46 47 37 48 49 39 50 1 2 LEDK LEDA1 LEDA2 LEDA3 LEDA4 IM0 IM1 IM2 IM3 RESET VSYNC HSYNC DOTCLK DE DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 SDO SDI RD WR RS CS TE VCC VCC VCC GND X+ MC33375 SS14 K A +3.3V 470 Q1 BC817 C DNP B E NRST 1 2 3 4 5 6 BC817 C +5V B MISO E LED CATHODE BAND MOSI K A SHLD D SCL1 SDA1 AREF AREF GND PWM13 PWM12 PWM11 PWM10 PWM9 PWM8 SHLD C PWM7 PWM6 PWM5 PWM4 PWM3 PWM2 TX RX 1 2 3 4 5 SERIAL CON8 Fig.1: the Altronics Touchscreen Maker Plate is based around a 32-bit ARM Cortex processor (IC1) and a 2.8-inch touchscreen which connects via a 50-pin flat flex cable. Most of the remaining circuitry is the power supply and bypassing for IC1, components related to the USB interface plus a set of five standard Arduino R3 headers for attaching shields. This design is software-compatible with the Arduino Due. siliconchip.com.au Australia’s electronics magazine October 2019  79 100nF 22pF R-78E5.0-0.5 TX RX 47 F D4 SS14 P3 0 SCL1 SDA1 AREF GND PWM12 PWM13 PWM11 PWM10 PWM9 PWM8 PWM7 PWM6 PWM5 PWM4 PWM3 PWM2 RX TX Q1 DNP C12 10 F REG2 15 10 F 22pF 10 F 100nF X1 10 F 12MHz 15 JP3 1k 22pF 22pF 39 100nF L3 VIN GND ERASE 100nF 6.8k 100k 100nF 100nF 100nF 39 L1 100nF 100nF 100nF 100nF 100nF D3 15 15 100nF RESET 37 1 CABLE TO LCD 10 F + IC1 SAM3X8EA-AU 10 F D1 REG1 73 K9660 D2 JP1 100nF 100nF S1 1 PS1 V1 109 6 GND V2 L2 www.altronics.com.au P8 CON2 10 F NC RST IOREF 5V 3V3 GND VIN GND A0 A3 A1 A2 A4 A5 V3 100 A LED1 470 Fig.2: the Touchscreen Maker Plate board uses mostly surfacemounting parts due to the limited space, all of which come presoldered. You only need to fit the connectors, switchmode regulator module (REG1), reset pushbutton (S1), jumpers and terminal block. The whole thing fits neatly in a standard wallplate. provides the logic supply for the touchscreen as well as running microcontroller IC1. It’s also fed to the IOREF and 3.3V pins on the shield headers. Two of the micro’s supply pins have LC low-pass filters to reduce noise, specifically pin 73 (the analog supply) and pin 41 (powering the USB transceiver). A third LC filter from the VDDOUT pin (pin 56) to VDDPLL (pin 34) smooths the internally generated supply voltage for the chip’s phase-locked loop, which derives its 84MHz master clock from the 12MHz crystal oscillator based around X1. Construction Fig.2 shows the PCB overlay diagram for this project. As mentioned earlier, most of the parts come already soldered to the board. All you really need to add is regulator REG1, the headers, jumpers, screw terminals and reset pushbutton (S1). The manual for this board explains that the standard Arduino header spacing is too wide to allow the Maker Plate to fit into a standard wall box, so two sets of headers are provided. The first is at the standard shield spacing, the second at a narrower spacing. You can use the standard headers for prototyping but you would need to wire up the shield using jumper leads, or make an adaptor so that it can remain attached when the unit is mounted on the wall. We suggest that you fit both sets of headers, as a mounted LCD will need to be removed to allow access for sol80 Silicon Chip dering. Since the LCD is fixed with double-sided tape, it could be difficult to remove. It’s best to use a spare shield as a jig to ensure that the shield headers are square and straight. Fitting the shield also gives you a chance to see what the clearances are like around the board. It’s very tight, with a typical shield only barely fitting lengthwise between the mounting screw-holes in the wallplate. A typical shield will also cover the reset pushbutton, although it is not entirely inaccessible. Many shields have their own reset buttons for this reason. An attached shield would also foul the DC input screw terminals. As such, we elected not to fit the screw terminals. You can solder wires to its pads instead. Alternatively, you could use a lower-profile screw terminal. After fitting the through-hole components, trim their pins to be as short as possible. This is necessary as the LCD is mounted on the back of the PCB with double-sided tape, and we need to avoid shorting out any pins on the LCD’s metal shell. Fitting the LCD is a bit fiddly, so we recommend test-fitting it without any tape to get a feel for how it all comes together. Once we were happy, we placed the double-sided tape over any exposed pins to ensure they were covered as much as possible and attached the LCD. There is some wiggle room in the PCB’s mounting holes, allowing the LCD to be centred in the bezel. Naturally, it helps to mount the LCD squarely and correctly within the marked outline. Australia’s electronics magazine The USB socket is accessed through a slot in the side of the wallplate; the wallplate will only attach to the PCB with one orientation because of this. We found that the thickness of the wallplate prevented some USB cables from plugging in completely, but the USB cable included with the kit worked fine. The slot for the USB socket is covered by the decorative facia cover that is provided, so this will need to be removed to access the USB port (eg, for programming). It is possible to notch out the wallplate further if regular access is needed to the USB port. All in all, the final product is quite tidy, but necessarily cramped. In just about all cases, a cavity in the wall or spacer block will be needed, as many of the components and headers protrude past the back of the mounting plane. Software The kit comes pre-loaded with a demonstration sketch programmed into the firmware, but you will need the Arduino IDE (integrated development environment) to make it do anything beyond this. The IDE is free and can be downloaded from siliconchip.com.au/link/ aatq We recommend using a recent version, especially as versions after 1.6.4 include support for the automatic installation of add-on boards and libraries. We used version 1.8.5. The Due board profile (compatible with this micro) is not installed by default, so after installing the IDE, you siliconchip.com.au will need to use the Board Manager utility to do this. Select the Tools -> Board -> Board Manager menu option, and search for “Due”. Fig.3 shows how the result should look. Click the Due entry and then click “Install”. The install process will take a few moments as the toolchain components (compiler etc) are installed, after which two new entries will appear in the Tools -> Board menu. They are “Arduino Due (Programming Port)” and “Arduino Due (Native USB Port)”. How do you power them? Powering these Touchscreen Plates on the workbench is one thing but more than once, the question arose, “how do you power them when they’re mounted in/on a wall?” It’s a fair enough question, too. But we figured that in the vast majority of circumstances, the devices being controlled or linked to would have the appropriate power supply available – 3.3V or 5V DC as the case may be . . and it Fig.3: this shows the results of searching for “Due” in the Arduino IDE Boards manager. You need to install this Boards package to be able to program the SAM3X8E microcontroller on the Touchscreen Maker Plate board. Once you’ve found it, simply click on the Boards package and then click the “Install” button (not present here because we’ve already installed it). Fig.4: note the search term we’ve entered in the box at upper-right. The first result is one of the libraries required to compile the demo code for the Touchscreen Maker Plate. Like with the Boards files, click on the entry once located and then click the “Install” button. Fig.5: the second of three libraries you need to compile and upload the demo code. The third one must be downloaded separately and installed from the .ZIP file (see text for details). siliconchip.com.au Australia’s electronics magazine should be a simple matter to tap off the power required. Power requirements for the Plates themselves are very modest. In the unlikely event that this was not possible, it may be necessary to arrange an external supply (eg, a plugpack). Working with an existing building might be problematic, but installing them in a new building should not cause significant dramas. While official Due boards have two USB sockets corresponding to these two entries, the Touchscreen Maker Plate only has the native USB port. This option should be selected to allow programming to occur. The correct serial port needs to be selected too (in Windows, check Device Manager). The programming port is presumably omitted due to space constraints. The native USB port can be used for programming, but is about 30% slower. The official Arduino advice is that the programming port is preferred, not just for speed, but because it’s possible for a bug in the loaded sketch to make the native port unavailable, thus leaving you with no easy way to reprogram the chip. Also note that the native port corresponds to the “SerialUSB” object, while the programming port corresponds to the “Serial” object, meaning that existing sketches that use the “Serial” object may need to be modified to communicate with a USB host with this board. To compile the example sketch (downloadable from siliconchip.com. au/link/aato), you need three extra software libraries. Two of these can be installed by the Library Manager but the third needs to be installed manually. The Library Manager can be found under the Sketch -> Include Library -> Manage Libraries menu. The required libraries can be found in this dialog, as shown in Figs.4 & 5. Like the Board Manager, once you’ve found the library, simply click on it and then click the install button. You can download a ZIP of the third required library from: siliconchip.com. au/link/aatp Once you have the file, use the Sketch → Include Library → Add .ZIP library menu item, then with the October 2019  81 file dialog box opens, browse to the downloaded file and click “Open”. If all is well, you should see a message that the library was installed correctly. The example sketch can now be compiled and uploaded to the board. Note that the “AltImg.h” file needs to be in the same folder as the sketch file. Uploading this sketch takes around two minutes. Most of the sketch size (and upload time) is due to the embedded graphics. The demo sketch shows a splash screen, followed by a set of text instructions which explain the calibration process which follows. After calibration, a simple ‘paint’ type program allows the touch panel and display to be tested. Hardware Arduino pin PWM6 (physical pin 135) of the Due controller is used to control the touchscreen backlight. It can be switched on and off or dimmed. This is the only pin on the shield headers which is used for other purposes. While the Arduino version of the Due has 54 I/O pins, all of its PWM pins are already shared with the shield headers, so this was unavoidable. Note that as the SAM3X8E microcontroller runs from 3.3V, you may find that some shields which are designed expecting a 5V microcontroller will not function properly with it. Further software development The TFT display library includes some more code examples. But note that those which incorporate touch sensing use a different touch library than the one which Altronics recommends, so they may need to be modified. For the others, all you need to do to get them to work is to find their control pin definitions and change them to suit the pinout on this board, ie: #define TFT_RST 33 #define TFT_DC 37 #define TFT_CS 38 You may also need to add some commands to the setup() function to turn the backlight on, like this: pinMode(6,OUTPUT); digitalWrite(6,HIGH); The examples we tried were quite quick at updating the display, as the library uses the SAM3X8E’s DMA peripheral to pass data to the screen efficiently. 82 Silicon Chip The sample sketches by default do not use the native USB port for outputting their debugging data. So you should change references to the “Serial” object to read “SerialUSB” instead. A ‘quick and dirty’ way to achieve this is to add the following line near the top of the sketch: #define Serial SerialUSB For developing your own programs, we suggest using Altronics’ demonstration sketch as a starting point, along with sample code from the TFT library. Kit #2: LCD Shield Maker Plate (K9655) The second kit is the K9655 Inventa 16x2 LCD Shield Maker Plate. It is based on an ATmega328P processor, the same one used in the Uno, although this particular design is more like the Arduino Duemilanove in operation. It also has a 16x2 character LCD for display and a nine-button membrane keypad for input. While it might appear from the photos that there are only five buttons, the remaining four buttons are unmarked. Along with the five marked buttons, they make up a 3x3 button grid. The circuit for this kit is shown in Fig.6. It uses an MCP23S17 I/O expander IC to interface the ATmega328P micro to the LCD, keypad, buzzer and relays. That means that most of the regular Arduino pins are still available for use by shields. The MCP23S17 is the SPI version of the I2C-based MCP23017. The circuitry at the bottom is similar to that of an Arduino Uno board, with the ATmega328P micro wired up to the usual headers, clocked from a 16MHz crystal and with a basic 5V power supply delivered by a 7805 linear regulator. There’s also a 3.3V regulator in case a connected shield needs to draw power from that pin, but it doesn’t run anything else on the board. I/O expander IC2 drives the 16x2 alphanumeric LCD module from seven of its GPA pins, configured as digital outputs. GPA6 (pin 27) drives the base of NPN transistor Q1 which connects the backlight cathode to ground, giving on/off control. Its anode is permanently connected to the +5V rail via a 200Ω current-limiting resistor. Similarly, GPA7 drives the base of NPN transistor Q3, and this controls auxiliary SPDT relay RLY1, with its three contacts wired to terminal block Australia’s electronics magazine CON7. So you can use it for whatever purpose you desire. The I/O expander GPB ports are used to sense button presses on the keypad, which is arranged in a 3x3 matrix, and its six pins connect back to GPB2GPB7 via header CON2. GPB1 drives the piezo buzzer directly while GPB0 controls another NPN transistor (Q4) which in turn switches another relay, RLY2, which has its contacts wired to terminal block CON8, again for general purpose use. The I/O expander SPI bus is connected to the usual Arduino pins of D11-13. Other devices can share this bus. Its CS line connects to either Arduino pins D9 or D10, depending on the position of JP3. This can be used to prevent conflicts with any shields used (assuming they don’t use both D9 and D10). NPN transistor Q2 is connected to the SCK pin (D13) so that LED3 lights up when there is activity on the SPI bus. LED1 is connected across the 5V supply, so it lights up when power is applied. The dotted red lines shown from the INTA and INTB pins of IC2 back to D2 and D3 on the Arduino via jumpers were not present on the version of the kit we received, but will be added to future kits. With the jumpers fitted, these will allow you to trigger an interrupt routine on the microcontroller if a specific button on the keypad is pressed, without having to actively ‘poll’ the keypad periodically. The board Unlike the K9660 Touchscreen Maker Plate, this one does need to be assembled. But it’s virtually all throughhole components, and not that many of them, so it isn’t a big job. The PCB overlay diagram, Fig.7, shows the board layout. The bulk of the components mount on the back of the plate. There is a Fig.6 (opposite): the circuit for the LCD Shield Maker Plate, which is based around an ATmega328P microcontroller, the same one used in the popular Arduino Uno. I/O expander IC2 is used to interface with the LCD and keypad, so that most of IC1’s pins are still available for other purposes, including connecting to one or more shields. IC2 also controls the piezo buzzer and the coils of two small relays which you can use for various purposes. siliconchip.com.au +5V +5V A  LED3 K 200 100nF 9 18 1k C Q2 BC337 Vdd RST GPA0 GPA1 1k GPA2 B GPA3 E 14 13 12 11 D10 GPA4 MISO GPA5 MOSI GPA6 SCK GPA7 CS IC2 MCP23S17 D9 20 JP3 19 17 16 15 GPB7 GPB6 INTA GPB5 INTB GPB 4 GPB3 GPB2 A2 A1 GPB1 A0 GPB0 Vss 15 2 4 21 22 6 23 24 Vdd RS BLA 16 x 2 LCD MODULE EN D7 D6 D5 D4 D3 D2 D1 D0 25 14 13 12 11 10 9 CONTRAST GND BLK R/W 7 8 1 27 C 1k 28 B 8 E 7 3x3 KEYPAD 1 6 2 5 3 4 4 3 5 2 6 1 R1  R2 R3 7  + PIEZO SOUNDER C1 K A LED1 1 B Q4 BC337 B E E BC 33 7 RST C 1k Q3 BC337 COM2 3 NO2 CON7 1 B E NC2 2 A C 1k 1k C3 CON8 D4 1N5819 A MOSI SCK RLY1 C2 RLY2 K D3 1N5819  K +5V   +5V MISO Q1 BC337 CON2 +5V SHLDE ICSP 5 16 26 10 D3 D2 VR1 10k 3 NC1 2 C COM1 3 NO1 SHLDD D1 CON1 1N5819 K 1 A + VIN 2 – SCL REG1 7805 47 F 25V GND SDA +5V OUT IN 100nF AREF 100 F 16V 100nF 100nF SHLDB 1 +5V +5V RESET +5V +5V GND 23 24 GND 1 F 27 VIN 28 SHLDA 9 A0 A1 1M X1 A2 A3 A4 16MHz 22pF A5 A 20 1 9 K LEDS K A SCLK/PB5 RESET/PC6 MISO/PB4 ADC 0/PC 0 PB1 ADC 1/PC 1 PB0 22pF LP2950 PD6 ADC4/PC4/SDA PD5 ADC5/PC5/SCL PD4 XTAL1/PB 6 PD3 RXD/PD0 GND 8 IN 14 Australia’s electronics magazine RESET D7 D6 D5 D4 5 D3 4 D2 3 TXD 2 RXD 2x 1k D2 1N5819 10k S1 SHLDC 6 +5V OUT D9 D8 15 GND 22 GND D10 17 11 TXD/PD1 XTAL2/PB 7 D11 12 PD2 10 MOSI 18 13 PD7 ADC3/PC3 19 D13 D12 16 PB2 ALTRONICS 9-BUTTON WALLPLATE With LCD siliconchip.com.au SCK MISO IC1 ADC 2/PC 2 ATMEGA 26 3 2 8P 328P 25 GND 1N5819 7 Vcc 20 AVcc MOSI/PB3 REG2 LP2950-3.3 OUT IN +3.3V +3.3V SC  21 Aref GND K D1 D0 CON4 1 GND 2 A GND 3 +5V 4 100nF RXI 5 TXO 6 DTR FTDI October 2019  83 Silicon Chip 1k + 10k 200 S1 100nF 100nF + 100nF GND DTR TX RX 5V CTS 1k B1 SHLDE IC1 ATMEGA328P 9 JP2 22pF 1M X1 22pF NC1 NO1 NC2 1k IC2 MCP23S17 CON2 1k COM1 R3 LED3 Q2 VR1 COMMON 10 VIN NO2 COMMON LCD1 1k 1k A0 A1 A2 A3 A4 A5 1k RLY2 Q1 GND IOREF RST 3V3 5V GND GND VIN 1 F 47F LED1 REG2 100nF D1 COIL COIL RLY1 COM2 100F 100nF Q4 Q3 D4 D3 REG1 NC 84 Programming connection 1k NO Jumper JP3 for IC2’s CS connection is actually just three sets of closely spaced pads. These are hard to get at once the rest of the components have been fitted, so at this point, you should figure out which pin to use (see Altronics’ instructions for more details) and bridge the two appropriate pads. We used D9 as that is the one used in the example code. The next job is to fit the SMD IC. Make sure its orientation is correct, tack it down and then solder the pins. Clean up any bridges with flux paste and solder wick. Then fit the remaining top-side components, starting with the shorter ones and working your way up to the taller ones. We used an Arduino shield that we had lying around as a jig to ensure that the shield headers were mounted square and straight. Check that IC1, the diodes and electrolytic capacitors are orientated correctly, as per Fig.7. Note the three resistors and one diode (D2) which need to be laid over to avoid fouling the wallplate surround later. REG1 and the electros also need to be mounted flush with the board. Make sure the component leads around crystal X1’s mounting position on the underside of the board have been cut as short as possible, then solder X1 in place, ensuring enough space between it and the component leads that it won’t short. Adding some insulation under the crystal body is a good idea; the Altronics instructions say to use some of the supplied double-sided tape in this role, so we did so. Their instructions also note that the pins for the LCD header are quite ALTRONICS K9655 INVENTA NC Assembly close together, so make sure you don’t bridge any of these during soldering. If you do, use some flux paste and solder wick (and possibly also a solder sucker) to fix it. Before fitting the PCB into the wallplate, we test-fitted the LCD and membrane pad to see that everything was working as expected. The connections for these parts are a little bit awkward, in that the sockets for both are very close. Note that the LCD connection is not keyed, so this should be checked carefully against the construction photos to ensure you plug it in the right way around. Once the LCD is correctly connected, apply power and the demo software should start up. You can then check that the keypad buttons all work. Each press on the keypad triggers an action on the board, such as a relay toggling or the buzzer sounding. NO standard Arduino R3 set of headers, including dedicated pins for I2C and SPI. There is no USB/serial converter, so serial communication and programming require a separate module. The serial header pinout matches many so-called ‘FTDI’ type USB-serial‑ converters, such as Altronics Cat Z6225. It’s quite a packed board, so much that the crystal oscillator for IC1 (an ATmega328P) is mounted on the back of the PCB. The only SMD part is IC2, and it’s quite large, so not difficult to solder. There are screw terminals for DC power in (up to 15V) and the two sets of SPDT relay contacts (for low voltage only – definitely not mains!). SCL SDA AREF GND D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 FTDI D2 Fig.7: the LCD Shield Maker Plate comes as a While Altronics Cat Z6225 bare PCB and a selection of parts. All the parts FTDI USB to serial TTL adapt- but one are through-hole types, so assembly is straightforward. CON2 is used to connect to er module could be used to the nine-button matrix keypad while LCD1 is program the LCD Shield Maker a flat flex cable connector for the 16x2 LCD. Plate, we tried using a CP2102- The relays are not suitable for switching mains based module instead, as we voltages as the tracks and pins are too close stock these in the SILICON CHIP together, and too close to other components. ONLINE SHOP (siliconchip.com. au/Shop/7/3543). The required wiring no IDE, instead of the Uno. Otherwise, you can treat this board like the Uno. is shown in Fig.8. It may be possible to change a While the CP2102 uses 3.3V logic levels, the ATmega328P can accept Duemilanove to the Uno by merely re3.3V digital signal levels even when placing the bootloader, which can be running from a 5V supply. The 1kΩ done from the IDE, but you need an series resistors on the wallplate board in-circuit serial programmer (‘ICSP’). limit the current flowing into the se- We haven’t tried this, but in theory, rial converter RX pin to a safe level, it should provide 1.5kB more of flash even though the Arduino’s output pin programming space. It should also speed up sketch uploads. However, we swings up to +5V. have heard reports that it may not work Software reliably, so we recommend caution. There are no extra libraries needed The Duemilanove processor is the same ATmega328P as used in the to program the demo sketch into this Arduino Uno. The main difference board (you can get it from siliconchip. is that they use different bootloader com.au/link/aatr). Just make sure to firmware. The bootloader is a small extract all the files in this package to piece of software that runs every time a folder named “K9655DemoCode”. the processor starts up, to allow new There are two extra files which prosketches to be sent from the Arduino vide functions to control the LCD, detect presses on the keypad and so on. IDE to the chip. The Duemilanove board profile is This means that you need to select the Duemilanove board in the Ardui- built into the Arduino IDE, so after Australia’s electronics magazine siliconchip.com.au SHLD SH LDE E block will be needed, as several components protrude past the back of the plate. GND GN D selecting this and the correct serial port, we were able to compile and upload the demo sketch. A good way to write your own code for this board is to make a copy of the demo code by using the File -> Save As menu option. This will make a copy of the K9655.cpp and K9655.h files as well as the main sketch file. As mentioned earlier, the MCP23S17 requires a dedicated CS (chip select) pin, which can be set to either D9 or D10 using the supplied solder jumper. If your intended application requires both of these, it may be possible to solder a wire directly from the middle pad of the jumper to an alternative pin, and modify the Altronics code to use that pin instead. 100nFF 100n FTDI 1k DTR DT R TX RX 5V These two Maker Plates fit a lot into a small space. The SAM3X8E processor on the TFT Touchscreen Maker Plate (K9660) is well-suited to the producing colour graphics for display on the LCD, with a faster processor and more RAM and flash memory than most Arduinos. All these features make the TFT Touchscreen Maker Plate versatile and, we think, professional looking. However, it is significantly more expensive than the LCD Shield Maker Plate (K9655), which is better suited to more basic tasks. The more limited RAM and flash memory do limit its capabilities somewhat, but it’s powerful enough for many basic applications. To purchase, visit your local Altronics shop or order from D2 CTS CT S 1k A2 A3 A4 A5 Conclusion 10k Fig.8: here’s how to connect one of the ubiquitous CP2102 USB/serial adaptors, available from the SILICON CHIP ONLINE SHOP (siliconchip.com.au/Shop/7/3543) to the serial header on the Touchscreen Maker Plate. This provides both serial communication between the computer and microcontroller, and allows you to upload freshly compiled sketches. their website at the following links (which also have more information on both products): TFT Touchscreen Maker Plate ($175): www.altronics.com.au/p/ k9660 LCD Shield Maker Plate ($84.95): www.altronics.com.au/p/k9655 Final assembly As you might expect, the board is a very snug fit for the wallplate, and we found that we had to tweak the mounting bolts slightly to get them to fit the holes in the PCB, as well as allow the PCB to fit. The two flexible cables (for the LCD and keypad) are also a bit awkward to fit. But it makes a neat package when you manage to put it all together. Like the TFT Touchscreen Maker Plate, either a wall cavity or spacer siliconchip.com.au Here an assembled K9655 plate is shown with a motor driver Arduino shield plugged in. There’s a huge variety of shields on the market to accomplish just about any task you can think of! Australia’s electronics magazine October 2019  85 Just what does “Home Automation” mean? It’s sometimes called a “Smart Home” but either term basically means engaging technology to make the decisions required to control any, or as many of, the devices in and around a home which you normally make the decisions to control yourself. Some of those decisions are made completely autonomously according to parameters you (or someone else) have set up. Others may require your input, either at home via some form of keypad or screen – or if you’re not home, via information sent direct to your smartphone (and your decisions sent back the same way and acted upon). Some of those “smart home” decisions, the ones often mentioned, include: • Climate control: turning on air conditioning or ventilation to maintain a comfortable temperature – eg, heating the home when it’s cold or cooling it when it’s hot. • Lighting control: turning lights on and off as required – for example, sensing whether someone is in a room and turning lights off when they’re not – but also setting the lighting level you prefer. • Blind and shutter control: you select the time or lighting conditions when you want them open or closed. • Entertainment control: Selecting what your hifi/TV/etc system plays for you – and the level it plays at – possibly by learning what your preferences are according to the time of day. • Security: maintaining a protection system in and around your home and reacting to any triggering it detects. • Access control: allowing access (even unlocking and opening doors) to your home for persons who have access rights and denying it for those who don’t – then choosing an appropriate course of action. • Appliance control: turning appliances on or off according to demand, to take advantage of lower tariffs, etc. But there are many other “things” which home automation can play a part in, such as • Building sensors – reacting to anything outside the “norm” such as fire, flooding, gas build-up, power outages, etc. • Personal health and safety – keeping tabs on who is at home, their health, medication reminders, baby monitors, etc. • Pool and spa pumps and automatic chlorinators. • Remembering – to lock the front door or close the garage when you forget (and just as importantly, NOT closing the garage door when something is in the way!). • And even to make your home look “lived in” while you are away – and reporting to your smartphone if something is not quite right! • Charging control: got a storage battery or maybe an electric car? You can choose when to turn chargers on, again by determining when tariffs are cheapest. And we’ve really only looked at the home here – but already, “farm automation” is making huge inroads into properties, 86 Silicon Chip managing water resources, stock levels and locations, even farm gates and so on. These are just some of the tasks that home automation either undertakes now or promises to undertake. (Obviously there are many more). But just how does it/can it? The interfaces The big sticking point, for the “average” person, is the interface between the computers or microcontrollers that are programmed to make the smart home smart . . . and the devices which switch, or measure, or adjust, or warn, or otherwise “do” the smart tasks. Of course, control circuitry is myriad. If you Google “home automation” or “smart home” on the net, you’ll get millions, perhaps billions of hits. It might take you a while to sort the treasure from the trash but it’s highly likely you’ll find something to do what YOU want to do (or very close to it). That’s fine – but once again, how does the “average” person actually do it? One of the “biggies” is that a large proportion of the home equipment lending itself to Home Automation is not only mains powered, it’s hard-wired (especially in existing buildings). Think lighting, for example. And in many countries, Australia included, working on mains wiring is illegal if you don’t have the appropriate licence. Where mains devices are plug-in, it’s less of a problem – though in some jurisdictions, even interfacing with those can be illegal. This has been overcome to at least some degree by many electricians “going back to school” and learning all about smart homes and their control. That’s fine – but still leaves the hobbyist out of the loop, so to speak. The big “IF” is that IF electrical wiring has been modified illegally and IF there is a problem (fire, for instance) not only is the hobbyist liable to be prosecuted but insurance companies may refuse to pay for any loss or damage. The software This is perhaps the easiest part of the whole smart home equation. With the proliferation of microcontrollers and similar devices, there is almost certain to be software out there to do whatever you want with home automation and the smart home – or at least close to it. Again, Google is your friend! Even many of the projects published in SILICON CHIP in recent years have code which, when you think about it, could be part of a Home Automation control system. We’re not going to dwell on the fact that you might not speak Arduino or Pi or Micromite or …...... – but it’s not hard to find someone who does (especially in online forums). Or perhaps it’s time to dip your toe into the micro pool and learn what it’s all about? SC Australia’s electronics magazine siliconchip.com.au