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External MCU programming STM32

Bruno Sena
Associate II
Posted on December 21, 2017 at 13:25

I've an Nucleo-f091rc, and i need using this board to programming an external STM32F070, using SWDIO, I've connected SWDIO, SWDCLK, NRST and GND. My external MCU have external 3.3V. When I try to connect I receive the mesage No target connected.

1 ACCEPTED SOLUTION

Accepted Solutions
Bruno Sena
Associate II
Posted on December 22, 2017 at 12:41

0690X00000609IIQAY.png

Sorry All.

I'm using the wrong pins to connect the MCU to my pcb board.

Pin 1 is the smaller, concave mark in the lower-left, and I'm using the pin 1 on 

larger mark in the upper-right.

Anyway my external MCU works  fine now.

Thank you All.

View solution in original post

11 REPLIES 11
AvaTar
Lead
Posted on December 21, 2017 at 13:42

I've connected SWDIO, SWDCLK, NRST and GND.

Have you verified your wiring with an ohm-meter (or something similar) down to the pin of your target ?

Aren't you wires too long ?

I've an Nucleo-f091rc, and i need using this board to programming an external STM32F070, ...

The Nucleo user manuals use to have a section about debugging external targets, did you follow it ?

Posted on December 21, 2017 at 13:44

If you have removed the jumpers on the Nucleo then the next most probable cause is the target isn't correctly powered.

Check VDDA connection 

Check part orientation 

Check NRST state 

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Posted on December 21, 2017 at 13:51

Hello AvaTar,

I'm working with this 2 days. I have read a lot of simililar issues like my.

''The Nucleo user manuals use to have a section about debugging external targets, did you follow it ?''

Yes, I did.

0690X00000609HoQAI.png

the boot0 pin have a 10k with the GND.

All VDD and VDDA have a 100nF 

VSS and VSS is plug on GND

I'm try using Keil to debug

0690X00000609HtQAI.png

Have you verified your wiring with an ohm-meter (or something similar) down to the pin of your target ?

Aren't you wires too long ?

Yes, i resold the MCU and Try using Another MCU and still with the same Error.

Thanks.

Posted on December 21, 2017 at 13:56

VDDA has 10nF with the GND.

NRST is plug with the Reset of nucleo Board.

I have removed CN2 jumpers.

Posted on December 21, 2017 at 13:57

Then it is more likely something to do with the design. Show portion of schematic with STM32 connectivity.

Try also USART1 connectivity via System Loader when BOOT0 pulled HIGH at reset.

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Posted on December 21, 2017 at 14:31

>>VDDA has 10nF with the GND. NRST is plug with the Reset of nucleo Board.

Ok, but what are observed voltages on pins? ie with scope or multimeter

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Posted on December 21, 2017 at 20:50

vdda 3,3V. 

Reset 0V.

I'm not using a external osc.

I'm thinking to solder my external MCU on nucleo on-board MCU... Because the on-board MCU works fine.

Posted on December 22, 2017 at 02:47

Reset 0V.

how can it be Reset Pin is 0V?!?! Something is pulling down this pin on your board?!

Posted on December 22, 2017 at 02:56

The STM32 can clamp it low, usually indicative of the power supply pins, or orientation issues.

'No target connected' = currently dead in the water.

The part doesn't need an external oscillator to function, runs off HSI. Consequently very few ways to get 'signs-of-life' out of a device. One way is to query the System Loader, as suggested earlier (USART1 PA9/PA10, 9600 baud 8E1, send in 0x7F pattern), and in many threads covering exact same topic area. Probably not accessible here due to broken forum, but likely cached via Google.

Have an FAE review the schematic. Definitely have some kind of design review before pulling parts and hair out.

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