Can the nRF51822 be used as a TWI slave?

[alex kim]

My development environment is PCA10028, SoftDevice 130, SDK12.3.0

Two nRF51822s were mounted in one board
One nRF51822 will be used as a TWI master and the other as a TWI slave
The question is
1. Is TWI communication between the nRF51822 possible?
2. If possible, how should the TWI slave nRF51822 be set up?

[bjorn-spockeli]

HI Alex, 

the nRF51822 only supports TWI Master operation and not  TWI Slave. Hence, there is no HW support for communication between two nrf51822s over TWI. 

Best regards

Bjørn 

[alex kim]

Hi, Bjorn

Thank you for your quick reply.

As mentioned in the above question, we need to communicate between the two nRF51822s.

Which communication method do you recommend for communication between the two nRF51822s?

Note that uart is used for other purposes.

Best regards

alex

[bjorn-spockeli]

The nRF51822 has two SPI interfaces, SPI0 (SPI Master) and SPI1(SPI Master or Slave) , so you can use SPI to communicate. May I ask what the use-case for two nRF51822 with a serial connection is? 

[alex kim]

Hi, Bjorn,

The use of two nRF51822s on one board is as follows
1. One nRF51822 acts as a Central.
- We plan to use "ble_app_multilink_central" for the app.
- Seven peripherals will be connected and "experimental_ble_app_blinky" will be used for peripheral app.
- If an emergency is detected, the status is reported to 7 peripherals and other nRF51822.
2. The other nRF51822 acts as a peripheral.
- The app will use "ble_app_uart".
  (smartphone app UUID: SerialPortServiceClass_UUID, "00001101-0000-1000-8000-00805F9B34FB)
- When emergency situation is received, it is delivered to smartphone.

What's wrong with developing these products?

Best regards,

[bjorn-spockeli]

The S130 SoftDevice v2.0.1 supports concurrent Central and Peripheral roles with up to eight concurrent connections so you do not need to have two nRF51822s one one board in order to have both Central and Peripheral.