2017-11-27 04:47 AM
I can't get a STM32 in 48 - pin Package to work. I need a minimal working reference.
I have a STM32F042K6T6, It works fine, no problems, when I am using it on a breakout board:
Reset pin voltage goes to VDD level, Debugger works, I have a firmware project with Display, External ADC, etc, everything works.
It is LQFP 32. I need more I/O's, so I decided to switch to a 48 pin device.
I picked an STM32L443CCT6 for that, and also because I want the FPU of the M4 and the low power features.
So this is a breakout board I prepared for that:
Problem is: I can't get it up and running.
I tried several times with different types of 64 pin STM32 devices.
The Reset pin voltage stays at VSS level.
I connected it as follows:
pin 7: 100 nF cap to GND (reset pin)
pin 8, 23, 35 and 47: GND
pin 9, 24, 48: VDD = 3V3
pin 44: 10 K resistor to GND (BOOT0 pin)
I also added a 10 uF cap between pin 23 and 24, and two 100nF caps between pins 8/9 and 47/48 (soldered on the bottom side)
Can anyone help ?
Maybe provide a working minimalistic connection exaple for a 48 pin STM32, if possible for the L443CCT6 ?
Maybe the problem is something else, maybe because it is a fresh device and the system clocks are not set correctly ?
Or does anyone know a better breakout board or a minimalistic reference board other than nucleo, i.e. no extra components ?
Or anything else maybe.
BTW I use an ST-link V2 with 4 wire: GND, VDD, SWDIO and SWCLK connected. On the STM32F042K6T6 is works fine, no problems.
I also have nucleo boards with F042K6T6 and L452RET6. None of them, howwever, use a 48 pin device.
#stm32-l4 #lqfp482017-11-28 03:05 AM
Check all connections directly at the mcu pins. Measure voltage. Add decoupling caps. Measure voltage with an osciloscope. Throw away the breadboard, today.
JW
2017-11-28 05:59 AM
That would be veeery helpful I guess
Did you use a blank device and were able to attach the debugger (ST-Link V2 I assume) ?
Did you check the behaviour of the reset pin voltage ?
Can you send an image of the board with the F072C ?
2017-11-28 06:25 AM
And you've confirmed continuity at the IC pins? NRST clamped a zero is indicative of the POR circuit being active.
Board using 49 pin device, same as 48 with a ground pad
https://www.tindie.com/products/TleraCorp/butterfly-stm32l433-development-board/
2017-11-28 06:56 AM
Clive, soldering MLF in a none-high tech environment is a PITA.
2017-11-28 06:59 AM
Provided more as a working board/schematic exemplar
2017-12-01 04:12 AM
OK, thanky you all for your suggestions. So I will make a PCB with correctly designed decoupling etc.The only way to find out
2017-12-01 05:07 AM
I can solder QFN housing, but I prefer LQFP because it's a bit easier and this reduces potential problems.