I'm trying to communicate with a ST MicroElectronics ST25R3918 NFC transceiver via I2C.
I'm using a nrf52dk_nrf52832, NRF SDK 2.4.0 in vscode.
I want to use only external pull-up resistors on SDA and SCL (the ST chip wants to run a 1MHz).
app.overlay has
&i2c1 {
status = "okay";
pinctrl-0 = <&i2c1_default>;
pinctrl-1 = <&i2c1_sleep>;
pinctrl-names = "default", "sleep";
};
with pinctrl of
i2c1_default: i2c1_default {
group1 {
psels = <NRF_PSEL(TWIM_SDA, 0, 30)>,
<NRF_PSEL(TWIM_SCL, 0, 29)>;
};
};
i2c1_sleep: i2c1_sleep {
group1 {
psels = <NRF_PSEL(TWIM_SDA, 0, 30)>,
<NRF_PSEL(TWIM_SCL, 0, 29)>;
low-power-enable;
};
};
I believe that the internal pull-ups (13.5K) are enabled, but I can't find the appropriate pinctrl statement to disable them.
Can you please point me in the right direction?
