IoT-based Home Automation Device

this is a power socket board which runs the 220VAC appliances which was controller by Blynk IoT app by using ESP8266 ard w, you can also see the app screenshots and suggest for adding more features in this device. Leave any querries in the box down below or just email us for any IoT project assisstance at neosmart.iot@gmail.com

Blynk old legacy iot app review (Neo-Smart)

here is a video in which we presented a comprehensive review of Blynk legacy iot app in Urdu language. We made many different projects with that app, purchased their professional version and practiced a lot with their local server provisioning also which made our IoT journey beautiful. Later we switched to new Blynk IoT app and made different commercial products with that.

Note: this app is now shut downed by Blynk inc. USA and new Blynk IoT app with more cool features is available on Google play store.

IoT-based Smart ATS Control Card (ESP8266)

Specifically this card is named "Mobogen" which is purposefully designed for smart phone application, so the user can monitor and control some specific features via his smart phone.

Terminal blocks: this card only has three terminal blocks as you can see in the pictures, the middle one with two screws on it, is simply for card's 12VDC power supply, as usual. Whereas the side blocks are connected with RELAYs open, close and common points for driving the switch and crank functions of the GENSET.

Microcontroller: in this PCB, ESP8266 is used for providing online connectivity whereas its program is compiled in Arduino IDE and new BLYNK IOT app is used for performing online actions.

Regulators: two voltage regulators are present on this board, first one is 12V to 5V whereas the second one regulates 5V to 3.3V for powering up the ESP8266. Power circuitry also has a 470uf cap and a 6.3uf capacitor which is a specific requirement for the ESP8266.

Two Relays: in this board, only two RELAYS are present for switch and crank purpose of the GENSET.

Transistors: two nos. of BJT BT136 transistors are used to drive the RELAYS when button is pressed on smart phone Blynk IoT app. app screenshots are also available at the end of this post.

LED indicators: two nos. Red colored LEDs are present on this board, which are associated with their respective RELAYS and present the ON/OFF condition of the RELAYS.

Note: this specific board does not have any sensing lines and relevant sensing components for mains or GENSET power detection as this design was only aimed for remotely START/STOP the GENSET.

GENSET Control Card with PIC16F683 (8 PIN)

In this specific ATS control card, you will see implementation of some good electronics and PCB designing techniques regarding its schematic design and will learn a lot. Primarily, this effort was aimed at designing a robust PCB with less functions but with a small size and very low-cost.

Terminal blocks: in this circuit we decided to move 220VAC signal away from other terminals thats why we gave separate three pin terminal at upper side, as you can see in the pictures and other two terminals at the bottom side, for the RELAYS. We connected only the COM and OPEN points of the RELAYS with the terminals, as this circuit only controls the switch and crank function of the GENSET.

Ceramic Caps: in this PCB, instead of using step-down transformers we used another low cost electronics design technique for sensing the 220VAC power lines from mains and the GENSET by using ceramic electrostatic capacitors and resistors of 2Watts, as you can see in the pictures. Two Red colored LEDs are also present to show the signal received by this circuitry. This technique essentially made us able to control the cost of the PCB for the mass production. This technique has also been proven itself after testing in industrial applications.

Rectifiers: we used two rectifiers of 1Amp to convert the signal from 5VAC to 5VDC for further conditioning, each line has a separate rectifier on it after ceramic capacitors.

Optocouplers: after rectifiers sensing lines also have two Optocouplers on them, which isolate the signal from controller side yet provide clean logic signal at the inputs of microcontroller being used in this circuit.

Regulators: we have only one 7805 voltage regulator in this circuit being used for regulating the 12VDC to 5VDC to provide power to the PCB and microcontroller.

Microcontroller: in this PCB we used PIC16F683 microcontroller which senses the presence of mains or GENSET power signal on its selected input GPIOs and performs the following functions.

--> If mains is present and GENSET is not present just make sure to keep all output RELAYS in off position.

--> If mains is off and GENSET is also off, controller waits for 30 seconds and then energizes the switch RELAY, waits for another 2 seconds and then energizes the crank RELAY for 4 seconds, looks for input power signal from GENSET if it is not present for 10 consecutive seconds, controller again energizes the crank RELAY for 4 seconds and repeats the same "check and do" process for 6 times if it senses the power signal from GENSET is present then keeps the switch RELAY on, keeps the crank RELAY off. You can also observe this circuit doesn't has changeover RELAY in it.

--> in third case when mains supply is restored, the controller senses its presence via one of its selected input GPIO and waits for 10 seconds and then turns off the switch RELAY which causes the GENSET to turn off, again it has no changeover control function in it.

--> if both supplies are off the controller tries to start the GENSET via same process described above in case two.

Two Relays: we used only two RELAYS in this design, aiming for a most cost-effective design this time, for a reputed customer. One RELAY controls the switch and second controls the crank.

Transistors: instead of using ULN2003, we used two separate transistors for driving the RELAYS and also for effectively controlling the cost of miniature circuit.

LED indicators: along with two nos. of Red colored LEDs for power lines indication, we also have one Green colored LED for switch function and one Orange colored LED for crank function of GENSET.

IC sockets: only one 8-Pin i.c socket is present on the circuit board for mounting the PIC16F683 microcontroller which is performing well programed functions.

Note: Specifically, a variable POT was also added in this design, for externally changing the delay of cranking time period of the GENSET, as some generators do start quickly but some take a longer cranking time. Therefore we decided to control the cranking time externally.

ATS Control Card with PIC16F88 (Prototype 3)

Terminal blocks: as you can seen in the pictures, i would like to start from terminal blocks as the right most terminal block with three screws on it, is being used for sensing the presence of 220V supplies from the mains and the GENSET. The middle screw is for neutral wires which are jumped together from both power sources. Whereas the side screws are for phase wires from both power sources. It is labelled on the board which screw is for mains and which one is for GENSET. Second terminal block from the right is for providing any 5V logic input to the controller from any outside device which may be required for any other function. The third terminal from right is being used to provide power to the circuit board it is usually 12VDC and comes from the battery of GENSET. Next terminals consisting of two screws are respectively for switch RELAY, crank RELAY and changeover RELAY driven by microcontroller's selected GPIOs.

Transformers: In this prototype we used 220V to 12V step down transformers for shifting down the level of input signal, suitable for PIC16F88 microcontroller sensing.

Rectifiers: we used two rectifiers of 1Amp to convert the signal from 12VAC to 12VDC for further conditioning, each line has a separate rectifier on it after transformer.

Regulators: after rectifiers input signal is further passed through 7805 voltage regulators and 5V signal is then applied to the selected GPIOs of PIC16F88 supported with 10K pull-down resistors. These input power sensing lines also have 470uf capacitor on each line for signal stability.

Microcontroller: in this prototype we used PIC16F88 microcontroller which senses the presence of mains or GENSET power signal on its selected input GPIOs and performs the following functions.

--> If mains is present and GENSET is not present just make sure to keep all output RELAYS in off position.

--> If mains is off and GENSET is also off, controller waits for 30 seconds and then energizes the switch RELAY, waits for another 2 seconds and then energizes the crank RELAY for 4 seconds, looks for input power signal from GENSET if it is not present for 10 consecutive seconds, controller again energizes the crank RELAY for 4 seconds and repeats the same check and do process for 6 times if it senses the power signal input from GENSET is present then keeps the switch RELAY on, keeps the crank RELAY off and energizes the changeover RELAY for shifting the utility load to the GENSET.

--> in third case when mains supply is restored, the controller senses its presence via one of its selected input GPIO and waits for 10 seconds then turns off the changeover RELAY then waits for 3 seconds and then turns off the switch RELAY which causes the GENSET to turn off.

--> if both supplies are off the controller tries to start the GENSET via same process described above in case two.

🔶 Relay 1 (Switch Relay) 🔶 Relay 2 (Cranking Relay) 🔶 Relay 3 (Transfer Relay) :

in this prototype, big RELAYS were used for a specific purpose, we came across the RELAY switching and power handling issues in 1st and 2nd prototype therefore we decided to improve the design by adding big L-Type RELAYS.

LED indicators: in this prototype, we also added the LEDs for separate functions, Red LED indicates the mains power and one of the Green is for GENSET power. While the other Green LED is for switch RELAY. Orange LED indicates for the crank RELAY and the white LED is for changeover RELAY.

IC sockets: a UlN2003 i.c is also present between the outputs of PIC16F88 and output RELAYS, which helps driving the 12VDC relays with the 5V logic signal from the microcontroller's output pins.

Note: Specifically in this prototype more effort were put in improving the PCB design of the circuit