quantzie

Hi I am building a circuit that is the same as this on the link http://www.iguanalabs.com/tempture.htm I am using a different microchip, the ATmega88. I am supposed to transmit the data through a wireless method but for testing purposes I just connected the pin3 of the microchip to pin 11 of the max232. The max232 section I powered using USB and send the data through serial like in the page. The chip + sensor section, I power it using a power supply at 5V currently. I am not getting the data I want through Hyperterminal on the PC. If I use the same ground and voltage source for both sections, the data is transmitted properly and Hyperterminal reads the data. Is there any way to solve it? I think it is a grounding problem

solved it already. no need for reply

I connected pin 1 to a side of a 1k resistor and pin 4 to the other. Is that the correct method to try it?

thanks a lot for the advice!!! I have ordered my components and if i'll have any other problems i'll post :)

The current consumption should be more than 5mA because there will be a wireless receiver connected to the circuit. Comparing circuits, would I need a voltage regulator for connecting the USB as a power source?

The specifications are to transmit the data through the serial port. Those links are very good though thanks for it. I still can't find whether I can just use the pins 1 & 4 and connect it to my circuit

My project is to create a device that will read temperatures and transmit data to the computer. My plans are to transmit the data through the serial port using the MAX232 and ATMEGA88 microchip. I do not think these are the problems but the serial port does not supply enough power for the application I am using. I want to power up the device using USB. Is it possible to just connect the pins 1 & 4 as V+ and GND to my circuit? If I am not mistaken it is 100mA and 5V supply from PC through USB.