While developing applications, it can happen that things go wrong. And in my case I ended up with two LPC55Sxx EVK boards on my desk, which seemed not to be usable any more. The issue: the boards were not accessible with the debug probe, because right after main they muxed the pins in a wrong way :-(.
The standard GDB debug connections (both on-board and off-board) were not able to regain access of the board, because the MCU was running into the fault condition pretty much right out of reset.
Luckily, after a lot of trial-and-error, I have found a way to recover them.
For more than two years I’m using the NXP LPC845 in my university courses. Beside of that it is used in many projects. First, because the LPC845-BRK board is small, breadboard friendly and inexpensive. Second, for many small projects that Cortex-M0+ provides just the right amount of processing power and memory.
If you search for ‘LPC845’ on my blog, you will find many articles about it. We are using the LPC845 in a research project, and one developer asked me why the LPC845 seems to run slower than expected. And I was sure that I wrote already an article about this, but to my disappointment: even Google did not find it? So complete this unfortunate gap, here is it: how to optimize the LPC845 and running it at full speed, with the hand-brake released.
Many embedded systems application need to store some kind of data in a persistent way: calibration values, settings or log information. For a smaller amount of data, using an external memory or file system is an overkill. In many system I’m using minINI to store key-value pars in in a ‘ini-file’ way, but it requires the use of a file system of some kind. minINI is great and efficient, and makes getting and storing data really easy. But for simple cases, a single FLASH memory page or sector is just all what I need. Instead managing that page directly, why not using minINI without a file system?