Part Number: CC2650
Hey guys,
So my problem is twofold, though I'm not sure if the causes are related.
I've designed a custom board using the CC2650 to control and sample a potentiostat circuit. I have two custom boards, board one works with the SmartRF06 development kit with the CC2650EM7ID carrier board, and it mates through the connectors P403 - P405. The other board (2) is a custom integrated single board with the CC2650 on it. Both have the same custom designed analog front ends and custom power supplies, and in the case of the custom board connected to the development kit, the power supply on the custom board powers the development kit. The custom board is programmed through the JTAG ten pin connector, so both MCU's (on devkit and custom board) are programmed simultaneously. Both setups run the same program, and both setups have the same start up problem.
The first problem applies to both setups, but board 2 is worse. When the setups are power cycled after the initial progrmming, the application doesn't seem to run. The program I'm running uses the LCDSmartRF06EB example project as a template, and so what I mean by "doesn't seem to run" is that the LCD doesn't display anything when it should automatically on program startup. LED1 doesn't start to blink either like it should when it's in while loop in the lcdLowPriorityFxn, and instead LED2 turns on. If the setup is power cycled quickly, off to back on in under half a second (rough timing, just switch it quickly) then the application will run like normal reliably on the development kit, much less reliably on the custom board. I thought it was a problem with the power supply (which outputs 3.3V for all the digital electronics), that it was starting too slowly, or had strange startup characteristics regarding inrush current in pulling the voltage down for a few tenths of a sec at the beginning, but when using a benchtop power supply to supply 3.3V directly to the digital electronics, the problem persisted. I tried reducing the capacitance (C19 10uF - 2.2uF and removing C20 - 21 and L6) at the output of some parts of the power supply (schem attached) to reduce the start up time, but because I had the same problem with the benchtop supply I'm starting to think it's not the power supply.
Even in those instances where the application seems to not run, the 3.3V digital supply seems to come up fine, and I see 1.68V and 1.28V on VDDR and DCOUPL respectively.
I am going to try running a different example program next to see if I have the same problem.
In the schematic below, U5 supplies the digital 3.3V rail. The rest of the IC's after the boost supply other analog circuits on the board.
The second problem I have is that on board 2, in the instances where the application does start, it does not progress to the lcdHighPriorityFxn on a button press. Instead it freezes on whatever loop iteration it is in, in lcdLowPriorityFxn. Here is the MCU schematic on the custom board, although I'm not sure it is a hardware problem. Anything else you guys need feel free to ask. Both of these problems have stumped me.
Thanks,
Christian
