4 Channel Programmable Relay Module. User Guide. Rev 9

Transcription

1 Channel Programmable Relay Module User Guide Rev 9

2 Get in touch with us! Please feel free to send a mail to one of the mail IDs below or use the Contact Us page at to drop us a quick message. Technical Help Got technical questions? Please write to help@numato.com Sales Team Questions about making payments, volume discounts, academic/open source discounts, purchase orders and quotes? Please write to sales@numato.com Webmaster Questions/Suggestions about our website? Please write to webmaster@numato.com Like us on Facebook! Visit our blog for news, updates and specials. Mailing Address Numato Systems Pvt Ltd st Floor, #6C Wipro Avenue Phase - Electronic City Bangalore, KA-6000, India * Mail orders, phone orders and direct pick up are not available at this time. Please visit our online store to place your order. Estimated shipping time to your address will be displayed in the shopping cart before checkout. You may use, modify or share this publication or part of thereof adhering to Creative Commons Attribution-ShareAlike.0 Unported (CC BY-SA.0) License. See complete license text at All trademarks are property of their respective owners.

3 Programmable Relay Module Channel User Guide Introduction Numato Lab's Channel Programmable Relay Module is a feature rich product that can be programmed with Arduino IDE. The USB to Serial Chip FTRL helps uploading sketches quickly to the board. This programmability gives this board ultimate flexibility compared to other relay modules where features depend on the preprogrammed firmware and offer limited customizability. The on board programmable relays, digital I/O's, analog inputs, Real Time Clock(RTC) and Micro SD memory card slot makes this module useful for learning as well as making sophisticated applications. Applications Home Automation Lighting Control Garden Equipment Control Industrial Automation Test Fixtures DIY and Hobby Relay operation by RTC circuit Data logging Board Features Atmega8p Micro controller with KBytes flash memory Arduino IDE Compatible FTRL chip for USB to Serial Interface SPDT V Mechanical Relays Digital I/O's PWM outs Analog Inputs IC Interface Real Time Clock(RTC) via IC Interface Battery backup for RTC Micro SD Card Slot via SPI Interface Indication LED for Power, TX, RX and Relays ISP for doing custom boot loader 6 MHz Crystal USB mini Connector for Connecting with PC 0 NUMATO SYSTEMS PVT LTD

4 Programmable Relay Module Channel User Guide This product is compatible with the following operating systems. Windows XP and later Linux Mac And any other operating system that supports USB CDC devices. The drivers for all above can be download for free from This module has four on board SPDT V mechanical relays and associated drivers capable of controlling a large number of devices including lamps, motors, locks etc...(please see recommendations for using this product with inductive loads elsewhere in this document). By default the board burned with Arudino Duemilanove w/ Atmega8 boot loader using the Arudino IDE. This module also includes Digital I/Os(multiplexed with PWM outputs), analog inputs, IC Interface, Real Time Clock using DS07, Micro SD Card Slot for storage, these can be accessed over USB interface and program easily with Arduino IDE for extended functionality. The module communicates with host PC over full speed USB link. When connected to PC, the module will appear as a serial port in Windows Device Manager (or a serial tty device in Linux and Mac). 0 NUMATO SYSTEMS PVT LTD

5 Programmable Relay Module Channel User Guide How to use the module The following section describes how to use this module. Components/Tools required Along with the module, you may need the items in the list below for easy and fast installation.. USB A to Mini B cable.. +V A power supply.. Medium size screw driver. Connection Details IMPORTANT Please exercise utmost caution while working with electrical mains or other high voltages. Failure to comply with safety regulations may result in injury and or death. Connection Diagram Above image shows basic connection diagram that can be used in most of the situations. The connection diagram is same for both AC and DC loads. Please make sure to use a freewheeling diode or snubber circuit if the load is inductive. More details about using inductive loads is available elsewhere in this document. Use a USB A to Mini B cable for connecting with PC. It is important to make sure that the wires used to connect loads are sufficiently rated to handle expected load current. Exercise caution while working with high voltages. Short circuits can cause damage to the module and the PC. The following sections identify individual connections in detail. 0 NUMATO SYSTEMS PVT LTD

6 Programmable Relay Module Channel User Guide USB Interface The on board full speed USB controller that helps a PC/Linux/Mac computer to communicate and control this module seamlessly. Use a USB A to Mini B cable to connecting with a PC. By default, the logic section of the module is powered from USB so make sure not to overcrowd unpowered USB hubs. Visit to buy cables and accessories for this product. Relay Contacts All contacts on each relay is available externally on screw terminals for easy user access. The relays are rated for AC and DC supply voltages. Please see the electrical parameter table for more details. Each relay has three contacts(c, NO and NC). C is the common terminal and is used in both normally open and normally closed positions. The contacts NC and C will be connected when the relay is turned off and will be disconnected when relay is turned on. And vice versa, the contacts C and NO will be disconnected when relay is turned off and will be connected when the relay is turned on. Table below summarizes possible relay contact positions. DC Power Supply Relay State Connection between NC and C Connection between NO and C OFF Close Open ON Open Close This module uses external +V power supply to function properly. External +V supply can be given through the DC jack on the board. Logic circuit can be powered from USB or on board V regulator from external +V. The logic circuit uses +V supply and the relay coils uses +V supply. By default the board is configured to use +V supply from USB. So an external +V power is not required unless USB port is unable to supply enough current. In most cases USB ports are capable of providing enough current for the module. The +V supply for the relay coils is not optional and the relay will not switch without this supply. Any off the shelf V DC power supply can be used for this purpose. Make sure to connect the power supply in correct polarity. If for any reason, an external V power supply needs to be used for the logic section of the module, the Jumper V-Select should be configured properly before connecting the power supply. Please refer to the marking on the board for more details. Connecting power supply incorrectly can cause damage to the module and/or other devices. 0 NUMATO SYSTEMS PVT LTD

7 Programmable Relay Module Channel User Guide On board Relays The board has four VDC SPDT mechanical relays that can switch up to 0A. The popular ULN00 IC is used to drive the relays individually, the inputs of the ULN00 IC are connected to the Atmega8P digital pins(pd,pd,pb,pd7) and the outputs of the ULN00 IC are connected to relays(0,, & ) respectively. Setting HIGH to these digital pins makes corresponding relay ON and Setting these digital pins LOW makes corresponding relay OFF. Sample sketch for testing Relay is available for download on the product page. The table below summarizes the digital I/O's used for relay triggering. PROGRAMMABLE RELAY MODULE ARUDINO UNO PIN Digital I/O's Atmega8P Relay 0 PD Relay PD Relay 9 PB Relay 7 PD7 In addition to on board relays, this board has three Digital IO pins that can be used for various custom applications. Digital IO th and 6 th are multiplexed with PWM outputs. All IO pins support V TTL signals. In output mode, each DIGITAL IO can source up to 0mA. So no additional circuitry is needed to drive regular LED s. A. K Ohms series resistor is recommended for current limiting when connecting LED to a DIGITAL IO. Sample sketch for testing Digital I/O's is available for download on the product page. The table below summarizes the Digital and PWM input positions on the header. PROGRAMMABLE RELAY MODULE ARUDINO UNO PIN Atmega8P PWM PD NO PD YES 6 6 PD6 YES 0 NUMATO SYSTEMS PVT LTD

8 6 Programmable Relay Module Channel User Guide Analog Input The board have analog input pins multiplexed with ADC. Analog inputs can read voltages at any level between 0 to volts. It is recommended to use a series resistor to protect the input from stray voltages and spikes. The internal Analog To Digital converter supports 0 bits resolution which is adequate for most applications. Sample sketch for testing Analog In is available for download on the product page. The table below summarizes the Analog and ADC input positions on the header. PROGRAMMABLE RELAY MODULE ARUDINO UNO PIN Atmega8P A0 A0 PC0/ADC0 A A PC/ADC A A PC/ADC A A PC/ADC Real Time Clock input The DS07 serial real-time clock (RTC) with low power, full binary-coded decimal (BCD) clock/calendar plus 6 bytes of NV SRAM. Address and data are transferred serially through an IC, bidirectional bus. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than days, including corrections for leap year. The clock operates in either the -hour or -hour format with AM/PM indicator. The chip has a built-in power-sense circuit that detects power failures and automatically switches to the backup supply. Timekeeping operation continues while the part operates from the backup supply. Sample sketch for exercising RTC is available for download on the product page. The table below summarizes the IC pins used for RTC functioning. PROGRAMMABLE RELAY MODULE ARUDINO UNO PIN Atmega8P SDA A PC/ADC SCL A PC/ADC 0 NUMATO SYSTEMS PVT LTD

9 7 Programmable Relay Module Channel User Guide Micro SD Card Slot The Micro SD uses SPI Communication which uses digital pins PB(), PB(), and PB() of Atmega8P with MOSI, MISO, & SCK. The CS pin is connected to the PB0(8) of Atmega8 digital pin. Please refer the following link for important notes on working with Micro SD Card on this board Sample sketch for test Micro SD Card is available for download on the product page. The table below summarizes the SPI pins used for Micro SD Card functioning. PROGRAMMABLE RELAY MODULE ARUDINO UNO PIN Atmega8P MOSI PB/MOSI MISO PB/MISO SCK PB/SCK CS 8 PB0 IC Interface Using this interface the board can communicate with a wide variety of chips that support IC communication. Interfacing with various shields, sensors etc are major applications of this. The table below summarizes the IC input positions on the header. RTC and these pins both share the same IC channel. PROGRAMMABLE RELAY MODULE ARUDINO UNO Atmega8P SDA A PC/ADC SCL A PC/ADC 0 NUMATO SYSTEMS PVT LTD

10 8 Programmable Relay Module Channel User Guide In System Programmer(ISP) ISP on the board can be act as an AVR ISP. This feature helps to program boot loader on to AVR(Atmega68/Atmega8). For additional information on burning the boot loader, see this link The ISP pins PB,PB,PB can also be used as digital I/O's. PROGRAMMABLE RELAY MODULE ARUDINO UNO PIN Atmega8P PB PB/MISO V V RST RESET RESET PB PB PB PB 0 NUMATO SYSTEMS PVT LTD

11 9 Programmable Relay Module Channel User Guide Driver Installation Windows This product requires a driver to be installed for proper functioning when used with Windows. The driver package can be downloaded from To install the driver, unzip the contents of the downloaded driver package to a folder. Attach USB cable to the PC and when asked by Windows device installation wizard, point to the folder where driver files are present. When driver installation is complete, the module should appear in Windows Device Manager as a serial port (see the picture on the right). Note down the name of the serial port (COM9). This information is required to control the module from the PC. Linux Please visit the page for more information about drivers for Linux. Once the driver is installed properly, the device will appear as a serial port. Mac Similar to Linux, Mac operating system comes with the required drivers pre-installed. When connected to a Mac computer, the device should appear as a serial port. 0 NUMATO SYSTEMS PVT LTD

12 0 Programmable Relay Module Channel User Guide Powering up Programmable Relay Module Channel. Select the appropriate jumper selection on the V-Select (Default jumper settings should work in most situations).. Connect +V DC Supply to the DC-Jack (Optional if you are not planning to use relays).. Connect the board to the host PC using USB Cable.. Install driver when asked.. Download the demo code for the relay from 6. Open the code in Arduino IDE (Download link Select the Board Arduino Duemlanove w/atmega8 board from tools menu. (see the image below). 8. Also select the serial port from the tools menu (see the image below). 0 NUMATO SYSTEMS PVT LTD

13 Programmable Relay Module Channel User Guide 9. Compile and upload code to the board. 0. Individual relays can be controlled by sending simple numbers to the Arduino serial monitor. The table below summarizes the input number to serial monitor and corresponding state change of relay. These commands will work only if the relay control sketch is uploaded to the board. RELAY command Relay state Relay 0 0 on Relay on Relay on Relay on Relay 0 00 off Relay 0 off Relay 0 off Relay 0 off 0 NUMATO SYSTEMS PVT LTD

14 Programmable Relay Module Channel User Guide Additional Information Analog to Digital Converter Some products do support Analog to Digital Conversion on some of the IO terminals. A list of analog input pins that supports analog function in this product is listed elsewhere in this document. There is no special command is required to execute to switch between analog and digital mode. The input voltage range of the ADC is 0 VDD (this product uses V power supply, so the range will be 0 V). The result will be returned as a number starting at zero and ending at 0. Zero indicates zero volts at the ADC input and 0 indicates VDD (V for this product) at ADC input. Using DIGITAL I/Os with switches It is possible to read the position of a switch that is connected to a DIGITAL IO. A SPST or SPDT switch is recommended to use with DIGITAL IOs. Push switches do maintain the contacts closed only for a very short time so using them is discouraged. The fundamental idea of using a switch with DIGITAL IO is to have the switch cause a voltage level change at the DIGITAL IO pin when pressed. Usually this is achieved by using an external pull-up resistor along with the switch. The pull up resistor is connected between the DIGITAL IO and VDD and the switch is connected between the DIGITAL IO and ground. When the switch is not pressed, the pull-up resistor will cause the DIGITAL IO to stay at VDD voltage level. When the switch is pressed, the DIGITAL IO is short circuited to ground and stays at zero voltage. This change in voltage and thus the position of the switch can be read using DIGITAL IO read command. Please see the recommended connection diagram below. Using relay modules with inductive loads It is important to take additional care when using relays with inductive loads. An inductive load is pretty much anything that has a coil and works based on magnetic principles like Motors, Solenoids and transformers. Inductive loads produce back emf when the magnitude of the load current changes. The back emf can be in the order of tens or even hundreds of voltage (See this Wikipedia article This effect is most severe when power is disconnected from inductive load because the rate of change of current is maximum at that point. Even though the back emf lives only for a very short time (a few milliseconds) it can cause sparks between the relay contacts and can deteriorate the contact quality over time and reduce the life span 0 NUMATO SYSTEMS PVT LTD

15 Programmable Relay Module Channel User Guide for the relays considerably. So it is important to take countermeasures to suppress the back emf to acceptable levels to protect relay contacts. Usually this requires connecting electronic devices in parallel with the load such that they absorb the high voltage components generated by the load. For solenoids, connecting a diode (fast switching diode is recommended) in parallel to the load (in reverse direction to the load current) is very effective. A diode used for this purpose is usually called a freewheeling diode. Please see the diagram on the right for connection details. A capacitor with proper rating is recommended for protecting the relay contacts when a motor is used as load. The capacitor should be rated enough to withstand the back emf that is generated by the motor. Please see the diagram below for connection details. Please note that the relay modules are NOT shipped with back emf suppression devices pre-installed. The exact kind of suppression device and the parameters of the selected device can vary depending on the load itself. Some of the parameters that affects the suppression device selection are the inductance of the load, power supply voltage, load current, physical size/structure of the load etc.. It is obvious that it is impossible for us to predict these parameters and design required back emf suppression device and incorporate that on the board. So we believe this is a task best left to the module user. There is an excellent article on designing back emf suppression on Wikipedia at 0 NUMATO SYSTEMS PVT LTD

16 Programmable Relay Module Channel User Guide Technical Specifications Parameter * Value Unit Basic Specifications Number of relays Number of Digital I/Os Digital I/Os(multiplexed with PWM outputs) Number of Analog Inputs Digital circuit power supply voltage (USB or external) V Maximum current drawn by digital circuitry 00 ma IO Specifications Maximum IO source current 0 ma Maximum IO sink current 0 ma DIGITAL IO input low voltage 0.8 V DIGITAL IO input high voltage V DIGITAL IO output low voltage 0 V DIGITAL IO output high voltage V ADC Specifications Resolution 0 bits Full scale range 0 VDD V Reference voltage VDD V Recommended Impedance of Analog Voltage Source. KΩ Relay Specifications Nominal relay coil voltage V Nominal coil power consumption (per relay) 60 mw Relay contact material Contact rating Maximum switching voltage Silver Alloy A: 0A 0VAC/ A 0VAC C: 7A 0VAC/ 0A 0VAC 0VAC/ 0VDC 0 NUMATO SYSTEMS PVT LTD

17 Programmable Relay Module Channel User Guide Maximum switching current A Maximum switching power Contact resistance (initial) 770VA/ 0W 00 Min at 6VDC A mω Life expectancy (Electrical) 00,000 Operations Life expectancy (Mechanical) 0,000,000 Operations Nominal insulation resistance 00 Min at 00VDC MΩ Maximum switching on response time 0 ms Maximum switching off response time ms Real Time Clock(RTC) Specifications Real Time Clock Chip DS07 Supply Voltage V V-BAT Battery Voltage V Battery Back-up current 00 na Oscillator frequency KHz Communication Interface Micro SD Card Slot Specifications Supply Voltage. V Communication Interface Card Slot type IC SPI Push through * All parameters considered nominal. Numato Systems Pvt Ltd reserve the right to modify products without notice. * 0 NUMATO SYSTEMS PVT LTD

18 6 Programmable Relay Module Channel User Guide FAQ Q. What are the serial parameters I need to use when communicating with this board? A. Since this module uses USB as the underlying transport mechanism, most of the serial parameters do not affect the communication. You can leave all parameters to any legal value (Eg: 00, 800, 9600 etc... for baud rate) except Flow control. Flow control needs to be set to None. Q. Where do I find driver for this product? A. Visit and navigate driver page. There will be a link to download windows driver. Linux and Mac does not require driver installation since in most cases they are shipped with the driver pre-installed. Q. The DIGITAL IO looses its previously set value when trying to read the status. Why it is so? A. When a DIGITAL IO is to output a value (high/low), that particular DIGITAL IO is put to output mode. When you are trying to read the DIGITAL IO, it needs to be put in input mode. In input mode, the DIGITAL IO will go to high impedance state and thus looses the previously set value. Q. What is the connector marked as ISP on this module? A. This connector is used to program the on-board micro controller. This connector is primarily intended for factory use. Q. I need a customized version of this product, can Numato do the customization for me? A. Yes, we can definitely do customization but there may be minimum order requirements depending on the level of customization required. Please write to sales@numato.com for a quote. Q. Where can I buy this product? A. All Numato products can be ordered directly from our web store We accept major credit cards and Paypal and ship to almost all countries with a few exceptions. We do have distributors in many countries where you can place your order. Please find the current list of distributors at 0 NUMATO SYSTEMS PVT LTD

19 7 Programmable Relay Module Channel User Guide Physical Dimensions Schematics See next page. 0 NUMATO SYSTEMS PVT LTD

20 POWER CIRCUIT V-EXT J JACK_P +V +V VI VO C C6 0.uF 7mfd 780_N C7 U 0.uF C8 7mfd R K PWR LED D RESET DIODE D6 0k R RESET SW SW_PUSH PB PB PB RST ISP P PB PB PB 6 RESET SCL SDA IC INTERFACE P SCL SDA 6 DIGITAL(PWM-) P PD6 PD PD A A A A0 P ANALOG IN PC/ADC PC/ADC PC/ADC PC0/ADC0 A A B - USB PWR - EXT PWR GS +V U A B VBUS 0E FERRITE J C 0.uF DTR USB C GS 0uF V-SELECT VBUS D+ Vbus C6 D- 0.uF Shield_ Shield_ PWR_FLAG 6 RESET GS PWR_FLAG GS C 7 0.uF U RTS C7 IO 0uF USBD- USBD+ NC RESET NC OSCI OSCO VOUT A IN 7 R NL U8 8 OUT MCP700 FTRL RESET TEST 6 V TXD RXD RTS CTS DTR DSR DCD RI CBUS0 CBUS CBUS CBUS CBUS C8 0uF R FT-TX K R FT-RX K RTS DTR R K TX 0.uF D C R K RX D C 0.uF 0.0uF 0.uF C 6 8 C AREF 0 AREF 9 IC A ADC6 ADC7 PD PD PB PD7 6 7 U I I I I I I6 I7 (PCINT0/CLKO/ICP)PB0 (PCINT/OCA)PB (PCINT/OCB/SS)PB (PCINT/OCA/MOSI)PB (PCINT/MISO)PB (PCINT/SCK)PB (PCINT6/XTAL/TOSC)PB6 (PCINT7/XTAL/TOSC)PB7 (PCINT8/ADC0)PC0 (PCINT9/ADC)PC (PCINT0/ADC)PC (PCINT/ADC)PC (PCINT/SDA/ADC)PC (PCINT/SCL/ADC)PC (PCINT/RESET)PC6 (PCINT6/RXD)PD0 (PCINT7/TXD)PD (PCINT8/INT0)PD (PCINT9/OCB/INT)PD (PCINT0/XCK/T0)PD (PCINT/OC0B/T)PD (PCINT/OC0A/AIN0)PD6 (PCINT/AIN)PD7 O O O O O O6 O7 ATMEGA8P PD OUT PD OUT PB OUT PD7 OUT PB0 PB PB PB PC0/ADC0 PC/ADC PC/ADC PC/ADC SDA SCL RESET FT-TX FT-RX PD PD PD6 6Mhz CRYSTAL k R X R M PD PD PB PD7 C0 PF C PF D RL0 RELAY PD OUT RL D RELAY RELAY0 RL RELAY PD OUT RL D7 RL RELAY PB OUT RL D8 RELAY RL RELAY R6 K R K R K R6 K +V +V +V K K K NC C NO NC C NO NC C NO B C X - BATTERY BT X CRYSTAL.768KHZ + X X X RTC INTERFACE VBAT DS07 8 X 7 X SQW 6 SCL VBAT SCL SDA SDA U 0k R7 K7 0k R8 R9 0.uF V PB0 PB PB C 7HC00 8 A Y A U6 Y 7 6 A Y 9 A Y 0 A Y 6A 6Y NC MICRO SD INTERFACE NC 6 MICRO_SD NC CS DI U7 V SCK 6 PB 7 DO 8 RSV SHIELD 9 0 SHIELD SHIELD SHIELD 8 ULN00 0.uF C9 COM 9 +V License : CC BY-SA Numato Systems File: ProgrammableRelayModuleChannel.sch Sheet: / Title: Programmable Relay Module Channel Size: A Date: 6 jun 0 KiCad E.D.A. PD7 OUT RELAY RL +V Rev:.0 Id: / K NC C NO C