gres
Full Member level 4
I would like to present temperature recorder with support for decure digital cards.
Base for that project is my testing board witch ATMega32 microprocessor. I add an digital thermometer DS18B20, RTC DS1307 clock and adapter that can be plug to ISP slot ( instead LED there is PB4 – slave select), that I made in thermotransfer mode. Attachment consist voltages stabilizer 3,3V (LF33CV), voltage divider from resistors and of course SD/MMC slot.
Diagram was taken from **broken link removed** Project in eagle is available at home page https://www.elektroda.pl/rtvforum/topic1562905.html
Software is written in C with FAT32 library from https://www.dharmanitech.com/2009/01/sd-card-interfacing-with-atmega8-fat32.html thanks to that I can easily copy data from recorder to PC. For log checking I wrote simple application ( Delphi7) that can generate diagrams from text files. Both software’s – for microcontroller and logs are hack out so you can find some mistakes. Microcontroller communicate with PC by RS232 series interface. To set data/ time or test thermometer/ SD card, you need to get in setup mode by jumper ( so far code is missing that function and I had to use “ust=1” line in right place). In normal work mode system save temperature every 5 minutes and send result to RS232.