STM32F4 with TDC7200 for ToF measurement

[Ananth C G]

Posted on June 22, 2017 at 07:46

Hi,

I am using TI's 

http://www.ti.com/product/TDC7200

with STM32F407. The interface is SPI. I am able to read and write into the

http://www.ti.com/product/TDC7200

registers (CONFIG1 and CONFIG2) over SPI without any problem. As per the TDC7200 Datasheet, upon writing a 0x01 into the CONFIG1 register of the TDC7200, a TRIGGER signal will be set by the TDC7200, which will be reset only after a START signal is received by the TDC7200.

The issue is that after I write a 0x01 or 0x03 into CONFIG1 register, I don't get any TRIGGER signal. I am able to read back the same CONFIG1 register and see that the register value has changed to whatever I have configured. The values of other registers are kept default and only CONFIG1 register is modified. I have checked the CLOCK - its 8MHz, SPI CLOCK - SCLK is 8MHz, and there is a LOW to HIGH on ENABLE Pin at the beginning as well (as per the datasheet). I have monitored the TRIGGER pin of the TDC using Oscilloscope, it doesn't go HIGH.

For my purpose, I am not using

http://www.ti.com/product/TDC1000

. Both TRIGGER and INTB of

http://www.ti.com/product/TDC7200

are connected to MCU (STM32F4) as interrupts. The purpose is to send START (followed by STOP) signals to the

http://www.ti.com/product/TDC7200

 upon receiving TRIGGER interrupt, and then get INTB interrupt from TDC7200 after STOP Signal and then proceed for calculations of TOF.

What could be the problem ? Why am I not able to get TRIGGER interrupt from

http://www.ti.com/product/TDC7200

? Is there something that I have missed ? Can someone help ?

The Measurement Sequence, as described in the TDC7200 datasheet is as below:

For reference I have attached the Datasheet of TDC7200 as well.

Thanks in advance.

-Ananth

#tdc7200 #stm32f4discovery-stm32f4

[waclawek.jan]

Posted on June 22, 2017 at 19:41

I have monitored the TRIGGER pin of the TDC using Oscilloscope, it doesn't go HIGH.

Did you measure directly on TDC7200's pin2?

Also check for shorts to ground and neighbouring pins/tracks.

Isn't the connected pin on STM32 set to output?

JW

[Ananth C G]

Posted on June 23, 2017 at 06:34

Hi Jan,

Thanks for the reply.

Did you measure directly on TDC7200's pin2?

Yes, I measured the TDC7200's Pin-2 directly. I have monitored the

connected STM32F4's Pin (PE14) as well. Both show the same.

Isn't the connected pin on STM32 set to output?

No. I have configured that pin as an external interrupt - Pin PE14 as

GPIO_EXTI14.

GPIO mode :* External Interrupt Mode with Rising edge trigger detection*

GPIO Pull-up/Pull-down : No pull-up and no pull-down

Is this the issue ?

On Thu, Jun 22, 2017 at 11:11 PM, waclawek.jan <

[waclawek.jan]

Posted on June 23, 2017 at 12:51

Sounds to be OK, I don't have any further ideas where to look... maybe you should try to as at TI.

JW

[mahdi zamani]

hi dear can share your sample code or library ?

[AKhan.0]

Sorry I am new to

TDC7200. I have one question. Is it possible to use TDC7200 without SPI or microcontroller?