TWIS operation on 20 Khz frequency?

RE: TWIS operation on 20 Khz frequency?

pradeep8892 — Fri, 15 May 2020 14:32:29 GMT

As in the infocenter documentation it is mentioned that, The TWI slave supports clock stretching performed by the master. So as we know that TWIS support 100 Khz to 400 Khz frequency range. So if suppose TWIS clock is set to 100 Khz, Then can we use clock stritching method to slow down the clock. So that we can receive the data from the master. If this thing is possible, can you please suggest me how can i set TWIS clock to 100 Khz and How can i implement clock stretching technique on TWI Slave. This would really great help.

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.nrf52832.ps.v1.1%2Ftwis.html

Thansk & Regards,

Pradeep

RE: TWIS operation on 20 Khz frequency?

WilliamEriksson — Fri, 15 May 2020 13:53:11 GMT

I once bit-banged I2C on a nRF52832, it might be your only option. In my case I just did it for debugging since the nRF52832 violated the timing specs for the accelerometer, it turned out (after x-ray scanning) that the accelerometer that I was trying to communicate with was just an empty capsule without any silicon in it, I had been scammed! Not very strange that it didn't work :D

RE: TWIS operation on 20 Khz frequency?

pradeep8892 — Fri, 15 May 2020 12:08:56 GMT

I am using nrf52832 as a slave, so using TWIS not TWI, There is a i2c master with SCL at 20 Khz clock frequency. So nrf52832 TWIS has to communicate with the i2c master and exchange the data. So can TWIS communicate with 20 Khz clock. Is there any technique method available?

RE: TWIS operation on 20 Khz frequency?

haakonsh — Fri, 15 May 2020 11:53:02 GMT

The nrf52832 does not support 20kHz TWI.

RE: TWIS operation on 20 Khz frequency?

pradeep8892 — Fri, 15 May 2020 09:02:08 GMT

Hi haakonsh,

May you please suggest me, what are the available method, which can enable NRF52832 TWIS to communicate with 20 Khz?.

If clock-stretching is the solution, how can i implement this to receive the data.

RE: TWIS operation on 20 Khz frequency?

haakonsh — Fri, 15 May 2020 08:07:18 GMT

Clock-stretching is used to synchronize devices, f.ex. if the slave requires more time to set-up buffers, etc. The frequency of the bus is unchanged, but an arbitrary length delay is added.