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9 years, 2 months ago.
Mbed KL46Z SPI clock Problem,
Hi ,
I am working with mbed KL46Z .I am interfacing mbed and a RF transmitter using SPI(with mbed as master). The pins work fine in the beginning(for about 2days).As time passes the SCLK of mbed stops working.
I tried debugging with osciloscope.The clock gives desired frequency when pin is not connected with anything.But as soon as I connect to the RF Transmitter I do not get any clock anymore.
We are taking utmost care about ESD. As a part of a team we have purchased around 12 mbed microcontrollers for our project. And have also tried with 3 other mbed KL46Z boards.Stilll the problem is persisting.
Can I please know any other reasons that may be causing us the problem.
Thanking You Dheeraj M Pai
1 Answer
9 years, 2 months ago.
Considering you say that without load it works fine, and several other boards have exactly trhe same problem, I would say it sounds like definately your RF transmitter is the issue. Either it could be broken for whatever reason, or possibly if it has dual uses for a pin, it might be that that pin is for whatever reason set to its alternate mode.
Simple way to check: Grab a 10k resistor (or any resistor tbh), connect it to that pin of your RF transmitter and its supply -> Do you measure 3.3V on the pin? (Earlier check to do: Do you measure 3.3V on its supply? Otherwise its ESD diodes will already do alot to reduce the signal swing of the SPI clock). Same thing also with connecting it to ground.