MODBUS COMMUNICATION

Dear all,

ModBus communication using ARDUINO UNO and mach3 CNC Analyzer. For this we used simple ModBus slave library. Here are the screenshots for easy understanding and configuration of mach3.

Download and install the mach 3 CNC Analyzer.

Open your session profile in mach3mill.

Open the ports and pins window by clicking on the config tab on the left top corner of the mach3 window. In this select the port enable, modBus input output support and also the ModBus plug-in support after that click on the OK tab.

After this select setup serial modBus in the cofig’s function next to config tab. Here enable the config tab by clicking on it and give the names as shown in the below figure. PORT number is the one which your Arduino is connected, address modBus is the address of the variable which you are going to read, direction input output is the IO for modBus, ensure that you have mentioned the correct baud rate and 8-2-N: 1 start bit, 8 data bits, 2 stop bits.

 Now click on the test modBus tab on the right top corner of the window. You can see another window.

Give the correct slave id(other than zero), starting address, total number of register you need to access from the Arduino and click on the open port now it will display no error message in the status bar. Click on the read tab to read the register values.

Now open the brain editor window in the operator tab. A new window will open when you click on the + tab. In this select the modBus and configure the parameters as shown in the below image. Similarly add other input, save the file with extension of .brn and close the window

In a dialogue box it will ask whether you want to terminate the label or not.

Open the brain control window in the operator tab

Click on all brains tab it will display the previously saved files and enable the correct file by selecting on it. Finally click on the view brain tab.  

BUJJI Tx MARK 2

Dear all,

Here is the BUJJI Tx schematic and PCB Layout.

BUJJI Tx mark 2

BUJJI Tx Mark II

Dear all,

It is designed in the general purpose PCB before making it into PCB and also to check whether it will come within the expected size. PCB size is 32x36 (grids).

Bujji Tx mark II

BUJJI SLIPPERS BEFORE WIRING

Good evening,

Here is the pictures of Bujji slippers before wiring:

Schematic diagram of Bujji slippers

BUJJI SLIPPERS

VU2VNK while testing bujji Tx was requesting a little more power and here is the Bujji slippers.

This is IRF510 based amplifier (non Linear), the design is based on 1978 ARRL HAND BOOK.

The below picture is work-in-progress.

A prototype is already built and now it is being relocated into a NUTCASE.

FILTER CHOKE

Good evening,

For one of our project choke is required. we used 24 SWG for making the choke. The resistance of the copper wire is 84 Ohms per Km,
The resistance of cooper wire for 1 meter is 0.084 Ohms. For 8 turns the length of the wire is 62 Cms  is < 60m Ohms. for 8 strands the resistance 6m Ohms. Otherwise the Voltage drop is HIGH when the current is around 20A.
Here we need the voltage drop is below 0.2 Volts.
The choke is implemented in the 40mm core as shown below.

Bujji Tx 3

Dear all,

Bujji Tx serial no 3 is ready with good looking and working best of our satisfaction. In this we used chebyshev low Pass filter to get less loss.

0.1dB CHEBYSHEV L.P.F for Bujji Tx.

Dear all,

0.1dB CHEBYSHEV L.P.F (11t-24SWG) for Bujji Tx  is given below, with a cutoff frequency of 10 MHz, The actual circuit is taken from the ARRL Hand book.

We connected 47E load in the output to the check the performance. The performance is satisfactory. 

BUJJI TX

Season's Greeting to all,

Here we come with a cute (BUJJI) Tx of 500 mW of power. This transmitter work at 7084 KHz or 7079 KHz frequency which is South India's famous LAKE CITY/GARDENCITY NET and CHARMINAR NET. The frequency of the Tx is stable because of the Crystal IF and is designed to operate with 9 V battery, 

The entire Tx will come in the NUTCASE box. Further details of the Tx will be updated soon.

EXPERIENCE WITH BUCK REGULATOR

We want to see the characteristics of buck regulator given in datasheet of SG3524. This is our first experience of BUCK Regulator (5V) without using the transformer and is working very nice.

Instead of TIP115 PNP transistors easily available BC557 and BEL369 are used to form the Darlington pair. The Input current drawn is 100mA@20V with the output of 300mA@5V. The circuit is working at 10 KHz frequency and the inductance is 1.2mH. The Core and bobbin are purchased from the JINANICA.TO increase the efficiency of the circuit schottky diode is used.

The circuit Diagram is taken from the SG3524 datasheet: click here fig 3:

The pictures of buck regulator is given below: