SPI Communication failed when STM8S is connected with STPM10

gopal1 · ‎2013-09-10

Posted on September 10, 2013 at 14:17

I am designing one energy meter product where I have connected my STM8S microcontroller with STPM10 energy meter IC. The controller is communicating with the IC via SPI communication. But while reading from the STPM10 IC, the data line(MOSI from controller) always remain in high state whereas other lines like SCL, SCS, SYN line are working fine. I have checked all the hardware connection and even the firmware. Don't know where i am getting wrong? Need serious help. I have attached the waveform of reading date from IC and the circuit diagram that i am using to interface STPM10 with STM8S

harsh · ‎2013-11-30

Posted on November 30, 2013 at 09:56

Hi Gopal,

My problem is similar to you. I am getting MSIO line constant HIGH from the meter.

If you've found out possible solution then let me know..

Thanking you...

pierreandre · ‎2013-12-05

Posted on December 05, 2013 at 13:26

How did you have connected the device?

I never used the STPM10, but it seems that the SPI interface is quite weird. As there is only one line for MISO and MOSI, the SDA pin; the SYN pin configure the SDA in read or write mode.

When the clock is on SCL the data are synched on SDA.

I use SPI in my application, but is more standard as the bus works like a linked shift register, push on MOSI and the register is shifted on MISO.

lowpowermcu · ‎2014-12-30

Posted on December 30, 2013 at 14:28

Hi Argail,

Can you share your SPI configuration?