Posted on 08 Aug 2008
It uses only 4 chips - 3 HC TTL’s and an Atmel At90S2313 microcontroller. It has a 5 digit LED display plus one used as a band indicator.the current consumption is less than 50 mA.It counts up to at least 52 MHz.The schematic is quite straightforward. There are two major parts, the display multiplexing and the counter stage.[more]
Posted on 29 Jul 2008
Here is some experimental hardware and software to transmit and receive AX.25 packets.
It is essentially a PIC-E clone designed around a Atmel AT90S2313 with a few extra bells and whistles.[more]
Posted on 07 May 2008
This is a digital thermometer with thermostat based on a DS1621 I2C thermometer with thermostat sensor control with an AT90S2313 or Attiny2313.You can replace the sensore DS1621 with DS1631.The temperature range is 0-125C. The thermostat range is 10-40C and you can set it with up or down buttons.With on/off switch you can turn on and off the load control. When is set to off the device acts as simple thermometer.[more]
Posted on 29 Apr 2008
This basically the frequency meter section of the frequency meter/pulse generator based on the AT90S2313 described elsewhere on this site, combined with the 100 MHz RF interface described in the page about the RS-232 to 100 MHz RF desktop channel adapter. Built and align this is the same manner as the 100 MHz RF desktop channel adapter. The frequency meter has a maximum input frequency of 4 Mhz and counts up to 65535. Time bases of 10 ms, 100 ms, 1 second, 10 seconds, and 100 seconds are selectable from the keyboard via the RF link.[more]
Posted on 02 Apr 2008
This is a simple circuit which can detect when you touch a sensor connected to one of the sensor inputs. It can be used to add a touch switch to your computer for example. It uses an AVR micro controller, the AT90S2313. This is overkill. You can add a lot more sensors than the two sensors.The basic idea is really simple. Make one pin output and another input. Connect a resistor between these pins.The resistor together with the human capacitance forms an RC network. The AVR set the output to low and then make a transition from 0V to +5V. 5 µs after this switch, the logic level at the input pin is sampled. If someone is touching the probe connected to the input pin, the capacitor (=human) will not be fully charged, and the input will be a digital 0 and vice versa.[more]
