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DIY Satellite Finder SFA-2007

Short videos (the second video contains sound):

Content:

• Introduction
• Features
• Schematic diagram and board
• Part information and construction details
• Firmware
• Software

Sat-finder 2007 is a portable spectrum analyzer of satellite signals. It based on an obsolete analogue front-end from an appropriate satellite receiver. The heart of the device is an AVR microcontroller, which controls the front-end and outputs graphical info onto small color LCD. This satfinder cannot define digital properties of signal such as symbol rate, FEC, BER etc., but it can see either analogue and digital transponders, including feed frequencies.

I am not positioning it as a serious tool, but it can be helpful in many situations. It easily may be used during dish installing and alignment, because the finder has on-board batteries and is able to work without AC-power.

I have built the first version of the sat-finder in the year 2007. That's why I saved the old name "Sat-Finder 2007" for the new, current revision of the device.

The features is a subject for the expanding and altering step by step.

The schematic diagram has large size, but it's quite simple. The heart of the schematic is ATmega16-16AU, running at 14.7456MHz. It also contains three step-up convertors, the first one is for an LNB, the second is for LCD's LED backlight and third one is for high voltage which is required for varicaps. The step-up for LNB is controlled by the MCU and it's based on MC34063 IC. The other step-ups are very simple, but they are sufficient for normal work. The important part of the schematic is the front-end. I used in my solution an old obsolete front-end from Samsung with part number TBCE18117IN. This is TSA5055 based module - I2C-controlled PLL-synthesizer. One more important thing is the LCD. I used my favorite LCD with LS020 controller from mobile phone Siemens S65. This LCD is well suitable for this device, because it has the SPI-interface, small power consumption, the known commands. Its color 2 inch screen has a quite good resolution. The RS-232 interface allows connecting the sat-finder to PC. There is a special software for uploading satellites data to the sat-finder via the interface.

Schematic diagram:

Sat-finder schematic rev 1.31 (631 downloads)

The board is optimized for the toner transfer method. All SMD parts are placed at the top side of the board, while the bottom side contains leaded capacitors, inductors, the front-end, few wire-jumpers etc.

PCB:

Sat-finder board template (286 downloads) - for the toner transfer method

The board is assembled, excluding the LCD, keyboard and two wires with power switch. These three parts will be mounted onto the plastic enclosure of the sat-finder.

I utilized an enclosure from Kradex with part number of "Z-44". This was the most suitable enclosure I found for the sat-finder. The enclosure consist of two identical parts, each part has four stubs inside to mount a printed board.

The enclosure "Z-44" (3D model):

You may download 3D-model of the Z-44 to learn its shapes more.

Z-44 3D-model (STEP and IGES) (169 downloads)

The parts with cuts for keyboard, LCD, connectors and the power switch:


The enclosure with the board, but without the LCD and the keypad:


Sat-Finder's connectors:


The LCD-unit and the keypad look as follows:

The detailed description of the LCD can be found here. This is 2 inch, 176x132 pixel, 16bit color, SPI-controlled LCD-module. By the way, I don't know keypad's marking. It's electrically organized as a matrix with four rows and four columns, having thus only 8 pins.

The top part of the enclosure with the LCD and the keypad fixed with a glue. But the keyboard may be left unglued due to small spacing between the internal surface of the enclosure and the board mounted with four screws.

The LCD and the keypad in the enclosure:


Internal connections between the board, the keypad and the LCD:


Assembled sat-finder with rechargeable batteries installed, without back cover:


View from left side:


Rocker switch I used:

At least there are two types of suitable front-ends for the Sat-finder. These are TBCE18117IN and TBVE18110IN. The main condition is that a front-end must be based on the TSA5055 (or SP5055) synthesizer.

Front-end "TBCE18117IN":

The firmware should be finished before its sharing.

SFA Connector is intended for uploading satellite data to the sat-finder. Also the program has additional capabilities.

To be continued. The work is in progress.

Some pictures