The Atmel AVR Dragon is a new programmer for Atmel AVR 8-bit Microcontrollers. I obtained this little beast because my old AVRISP serial programmer was useless due to lack of serial hardware on my PC. The Dragon was quite inexpensive and readily available at DigiKey. It promised to not only provide ISP (In-circuit Serial Programming), but also JTAG, debugWire and high voltage programming for AVR device. It arrived in a very stylish red little box, but no cables, enclosure or anything else for that matter. After some searching I came across the Serpac H-65 enclosure. It proved to be a perfect fit for “my” Dragon.
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I needed a device to test R/C servos. Hooking up receiver, battery, servos and then running the transmitter with the antenna extended inside the house was awkward. I thought this could be a nice little project for some microcontroller. After a long abstinence from PIC assembler, I downloaded the latest MPLAB release and programmed away. Here it is, the first cut of my servo tester.
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During the summer of 1998 I built yet another PIC based clock. I had an old LED analog clock kicking around. It was a CMOS logic design built from an ELV (a German electronics magazine) kit. The clock lost its time every single time there was the slightest brownout, it bothered me to no end. So I set out to reuse some of the parts and built a PIC based replacment. The most significant item on the feature list was a low power time keeping mode to keep the time ticking but the display dark during AC power loss. What can I say, it actually worked! The clock was able to keep time for several minutes running on just a larger capacitor (where the schematic says ‘battery’).
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During spring and summer of 1998 I developed my second project utilizing a Microchip PIC processor. The primary purpose was to explore character LCD displays and 2-wire bus (I2C) devices with a Microchip PIC microcontroller. The project was a digital room thermostat with multiple setpoints at different times of the day.
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It was February of 1998 when I first put my eye on the Microchip PIC microcontroller product line. It all started many years earlier with a Commodore C-64, followed by homebrew 6502 hardware projects and a fair bit of assembler programming on the 6502. Maybe some day I will find those notes if they still exist. After the 6502 adventures came a 8051 based project. In those days flash memory or EEPROM were unheard of. The project called for a single chip embedded processor. Philips made it, but only with masked ROM. For development, an 8051 with piggyback EPROM was available. Yes, the cermaic body of the 8051 actually had gold pins for an EPROM on its back! Unfortunately that chip was prohibitively expensive (for a student budget) and the project never materialized beyond hardware concept and some initial coding.
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