|Salae Logic in action!|
As soon as I opened the box, I connected it to sniff the SPI lines between my msp430 and cc2500 radio. It took me maybe 10-15 minutes to set up everything, including the Salae software to decode SPI on the fly. I ran my radio-setup code and observed the logic output. It seemed like something was happening, but it wasn’t quite working.
|First capture with msp430g2533|
So I went into the datasheet and figured out how to fix the clock problem.
|‘Correct’ capture with the msp430g2452|
I tried it again and, not surprisingly, it failed. Looking more carefully at the MISO/MOSI lines, I realized that they were backwards! Turns out that the SPI IO pins do not match between the msp4302533 and the 2452. I swapped two wires and everything started working!
While I was really happy I fixed the problem, this means that my previously mentioned PCB will only work with one of the two devices. My plan is to use the more expensive 2533 as a PC-to-radio bridge, since it has both a hardware UART to talk to the pc and hardware SPI to talk to the radio. The cheaper 2452 only has one SPI to use the radio.
|Launchpad with cc2500 Radio and Salae logic|
In the end, I’m still happy. The Salae logic was extremely helpful and easy to use. It took me less than an hour to solve a problem I hadn’t figure out in two days! Now I will be able to focus much more time in coming up with good radio libraries, instead of debugging silly problems.