I'm designing the avionics portion of an ADS-B transponder and have everything done except the one thing I just can't figure out is decoding and encoding the baseband signal. I'm kind of under the gun to get things moving along for my senior design project so that's why I'm reaching out on here so forgive my ignorance. I have been spending a lot of time learning the ins and outs trying to understand but just hitting a wall.

Another person in my group is designing the RF portion and from what he says we got an RF LDMOS producing baseband signals and I have to generate a signal as well to go to it. MODE S 1090 Extended Squitter

I'm using an ATSAM MCU and currently have the schematic made for ATSAMC21G but from what I've been looking at and asking on ATMEL community forums it might not be powerful enough and might have to use ATSAMD or ATSAME models for a bigger clock frequency. I have been looking over the data sheets and not sure if I need to tie this into the TC/TCC, USART, LIN, ADC, PWM, or something else. Once I know how to tie it all together I can get my PCB laid out and ordered. While I wait for that to be made I can figure out the code portion.

I again am sorry for being a newbie at this... my classes thus far have just been really basic MOFSET circuits so any help would be appreciated.

  • \$\begingroup\$ I am not sure what you want from us, a design for that transceiver? \$\endgroup\$
    – PlasmaHH
    Mar 22, 2018 at 17:45
  • \$\begingroup\$ just need help understanding what peripheral on an MCU would be used for decoding a baseband signal from the radio. There is an RF unit that will convert it to pulse widths of 0.45us within 44mHz clock. \$\endgroup\$
    – BrownKuma
    Mar 22, 2018 at 17:50
  • \$\begingroup\$ 44mHz= 44 milliherz. Easily handled by the slowest microprocessor. If you meant 44 megaherz, that's a much different problem. \$\endgroup\$
    – JRE
    Mar 22, 2018 at 19:07
  • \$\begingroup\$ The peripheral you're probably looking for is the Input Capture Module. This can record the timestamp when a particular event occurs, such as a rising or falling pulse. \$\endgroup\$
    – jramsay42
    Mar 23, 2018 at 0:10


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Browse other questions tagged or ask your own question.