susano
Junior Member level 1
hi all, i'm working on a positioning project, using a sim508 evaluation board(evb) and a simple board for an atmega32 micro controller. i have problem connecting these two together through usart(Rx and Tx pins):
both evb and avr board are working well independently (while testing with PC), but when i connect them(evb and board) together, there's no data transferred. even, in most cases, as soon as i connect the board to the evb, its gsm part turns off! and after disconnecting the board, it turns on again by itself!!!
i've checked all the connections(usart, power supply,etc.) and i programmed the avr micro as the gsm default baud rate(115200mbps);besides, both have the same input voltage level(5v),... can any one please help me with this strange problem which has involved me for several days?
the schematic of avr board has been attached.(an LCD and one mmc are used too)
thanks in advance for your help...
both evb and avr board are working well independently (while testing with PC), but when i connect them(evb and board) together, there's no data transferred. even, in most cases, as soon as i connect the board to the evb, its gsm part turns off! and after disconnecting the board, it turns on again by itself!!!
i've checked all the connections(usart, power supply,etc.) and i programmed the avr micro as the gsm default baud rate(115200mbps);besides, both have the same input voltage level(5v),... can any one please help me with this strange problem which has involved me for several days?
the schematic of avr board has been attached.(an LCD and one mmc are used too)
thanks in advance for your help...
