Dilshan R Jayakody’s Web Log

In this project, we built an STM8S005C6T6 based Ethernet development board for our IoT experiments. This development board consists of ENC28J60 , 10BASE-T stand-alone Ethernet controller, CH340G , USB serial interface, 2 LED indicators, and passive buzzer unit. The firmware framework for this development board has been developed using SDCC . To enable IPv4 support, we convert the EtherCard driver, which is available for the Arduino platform. The current version of this driver supports all other EtherCard functions except TCP support. Finished STM8S005C6T6 IoT development board. In the given design, the SPI terminals of the MCU are connected to the ENC28J60 Ethernet controller. All SPI terminals, such as MISO / PC7 , MOSI / PC6 , and SCK / PC5 , are connected directly to the Ethernet controller. In addition, the PC4 terminal of the MCU is used as ENC28J60, CHIP-SELECT .  The CH340G USB serial interface is connected to the UART2 terminals of the MCU. In STM8S005C6T6, the UAR...

This project introduces an open-source, ATmega328 based, configurable NTP clock with a 2.3-inch, 7-segment display driver. This clock automatically obtains time from the configured NTP server and updates the date and time of the built-in RTC (real-time clock). If the connection to the NTP server is lost, the clock continues to run using its built-in RTC. Finished NTP clock driver PCB. All the parameters of this clock can configure using its USB base serial terminal. The firmware of this clock supports both static and DHCP addressing modes. Apart from that, parameters such as NTP server address, time-offset, and clock display formats can change through the menu-driven configuration terminal. This clock is designed to drive large common-anode, 7-segment displays. The prototype version is assembled using four individual segments of 7.2V, 2.3-inch, red color displays ( FJS23101BH ). To archive, the necessary high output voltage and the current, the 7-segment display output stage of this ...

In last year we spend a lot of time and effort to wire our new house by ourselves. To complete this job we took nearly 2 ½ months and it includes wiring, fixing electrical fittings, communication equipment, etc. In this post, we describe how we archive this task with some technical details. Due to a large number of electrical points, we decided to use 3 phase electrical wiring in our house. To make it simpler we divide entire house wiring into 3 isolated circuits with 3 separate distribution boards. High-level design of our AC wiring systems is illustrated in the below diagram. High-level electrical wiring diagram up to distribution boards In the above circuit, the 3 phase AC line is first fed into 4-pole 40A isolator . Then it connected to 4-pole RCCB with 3 separate indicator lights. We use indicator lights to see the status of each phase, easily at any time. After RCCB we fed each phase into 3 separate distribution boards. As seen in the diagram the first (phase) circui...

This is an automatic Cat6 / Cat5 network cable tester designed using NE555 timer and 4017, decade counters. This unit test all 8 wire lines of twisted pair network cable and indicate pass/fail status with a single LED. We design this unit to test network connectivity issues in Cat6 / Cat5 cable systems and it is capable to check both crossover and straight-through type network cables. A prototype version of network cable tester. The recommended way to construct this circuit is on PCB. Both Master and Salve units need to be built on two separate boards. To perform test one end of the network cable must be connected to the Master unit and other ends need to be connected to the Slave unit. After connecting both Master and Slave units press " START-TEST " (S1) button to perform the test. Status of the cable is indicated through LED2 ( PASS indicator). PCB and schematic of this unit are available to download at google drive and easyeda.com .