AVR Projects By Dim

ATtiny45 Development Board

noreply@blogger.com (dim) — Tue, 08 Dec 2009 21:31:00 +0000

During development of a project with ATtiny45 i experienced some difficulties with programming with STK500, so i decide to build this tiny board.
Nothing Fancy about it but i am sure you find it useful in your experiments with that micro.
It can also be used with ATtiny25 and ATtiny85 because of the same pin out (read the pdf from Atmel for the differences).
In header CN1 comes all the available ports of micro except RESET.
With the JP2 and JP3 headers you can select if the PB3 and PB4 are connected to the external crystal or to the CN1 header so the can be used as ordinary ports. You have to program the appropriate fuses of course.
The JP1 header is used for programming the micro.

This is the picture of the schematic:

This is the picture of PCB and silkscreen:

Click for larger view.

Here is a pdf file with schematic and PCB with 1:1 print measures:

ATtiny45-development-board.pdf

You can download .sch and .brd files for Cadsoft's Eagle design program from here:

Attiny45 development board.sch

Attiny45 development board.brd

For questions e-mail me to: dselecdim at gmail dot com

Thermometer-Thermostat

noreply@blogger.com (dim) — Tue, 08 Dec 2009 21:21:00 +0000

This is a simple thermostat that i designed to use with my central heating system. When is not in use acts like a thermometer.
The prototype uses the AT90S2313 but it's obsolete now, so i changed it with the pin to pin compatible ATtiny2313 (the photo shows my first prototype).
With the on/off switch (S1) you can turn the device on or off. With the up (S2) and down (S3) you can set the desired temperature between 10 and 40 degrees Celsius.
When you turn the device on you first see the ON sign, then you see the temperature that the thermostat is set and at last you see the current temperature. If the current temperature is lower than the set temperature, the load is connected and the decimal point of the second digit is blinking. At any time you can set the temperature of the thermostat by pressing the up or down switches.
When you press any of the up or down switches momentarily you can see the current thermostat temperature. Pressing again the temperature change. To turn off the device just press the on/off switch again.

The schematic of the thermostat is shown here:

The PCB:

The Silkscreen:

Click on the images for larger view.

The schematic and the PCB is also available in Cadsoft's Eagle design program format:

thermometer.sch

thermometer.brd

The program for the micros is written with BASCOM-AVR

The files for ATtiny2313:
thermotiny.hex

thermotiny.bas

The files for AT90S2313:
thermo.hex

thermo.bas

If you are going to use ATtiny2313 you can omit the 4MHZ crystal and the two ceramic capacitors C2 and C3, using the internal oscillator tuned at 4MHZ. You have to omit the two resistors R12 and R13 as well.
The appropriate fuses for ATtiny2313 must be programed by you because the micro is shipped with internal oscillator tuned at 1MHZ by default.
Go to AVR Fuse Calculator, set the appropriate micro and select the settings in the menus (see the photos, click for larger view).

For internal oscillator set:

For external oscillator set:

You can program the micro on board using then 6-pin header JP1. if you use the STK500 remember to remove the VTARGET jumper or the STK500 maybe damaged.

For questions or comment mail to: dselecdim at gmail dot com

RGB Pattern Generator (PAL B/G)

noreply@blogger.com (dim) — Tue, 08 Dec 2009 21:08:00 +0000

This is a pattern generator with 13 images and 1KHZ tone, good for testing LCD TV's, projectors and cathode ray tube TV's.
The project is based on ATtiny2313 running at 20MHZ. The horizontal frequency is 15625HZ and the vertical frequency is 50HZ (Europe standard).
With the button S1 you can select the images one by one and with the button S2 you can turn the sound on and off (see the pictures below).

This is the schematic:

And this is the PCB and silkscreen:

You can download a pdf file with the schematic and pcb from here:

attiny2313-pattern-generator.pdf

Here are the files for Cadsoft's eagle design program:

ATtiny2313 pattern generator simple.sch
ATtiny2313 pattern generator simple.brd

The program inside the AVR was made with BASCOM-AVR. With the trial version provided you can make modifications in the program if you want to.
Here are the source code and hex file:

ATtiny2313 pattern generator simple.bas
ATtiny2313 pattern generator simple.hex

The ATtiny2313 is shipped with internal oscillator activated by default, so you have to program the appropriate fuses yourself. Goto Engbedded AVR Fuse Calculator site, select the appropriate microcontroller and set the settings as you see in the picture below. The program will calculate the appropriate fuses settings. Put them in your programmer and program the chip.

This is the picture of the settings (click for larger view):

Important!

A bug found in the placement of transistor T1 in PCB.
The correct is the reverse of the drawing in silkscreen. The schematic it's ok.

For any questions submit a comment or mail me to: dselecdim at gmail dot com

Pcb countdown timer

noreply@blogger.com (dim) — Tue, 08 Dec 2009 15:50:00 +0000

This is a countdown counter based on ATtiny2313, primary developed for my PCB exposure box, but it can be used for other purposes too.
The counting range is between 1 and 90 minutes and it can be adjusted with up or down buttons (high and low in the pictures).
After the desired time is set, the countdown starts by pressing the start/stop button (on/off in the pictures). By pressing the same button we can interrupt the counting at any time we want.
After the count expires we hear a beeping sound and the load is disconnected. By pressing start/stop button we reset the counter and we are ready for another lap. All actions included the time remaining are shown in the LCD display.
The schematic is shown here:

And the PCB:

Click on the images to get larger view.
The timer was originally build using the AT90S2313 but is obsolete now. Anyway the ATtiny2313 and AT90S2313 are pin to pin compatible and you can use it if you have it.
The code for the micro was developed using BASCOM-AVR. Download the source code and the hex file from here:

Source code: timer16LCD.bas

HEX file: timer16lcd.hex

The schematic and pcb was made with Cadsoft's eagle. Download the .sch and .brd files from here:

.sch file: countdown timer.sch

.brd file: countdown timer.brd

You can program the ATtiny2313 on board by using the 6-pin header which is compatible with the 6-pin header of STK-500. If you use STK-500 to program the micro you have to remove the VTARGET jumper first or the STK-500 will be damaged. The ATtiny2313 is shipped with internal oscillator selected by default, so you have to program the appropriate fuses by yourself. Use the on-line AVR Fuse Calculator and set the settings for the fuses (see the photo, click to get a larger view).

if you have any questions submit a comment or send e-mail: dselecdim at gmail dot com