stmhal: Document physical pins for SPI, I2C, UART busses.

1 files changed, 5 insertions, 0 deletions

diff --git a/stmhal/i2c.c b/stmhal/i2c.c
index d3aca36d3..00501a57d 100644
--- a/stmhal/i2c.c
+++ b/stmhal/i2c.c
@@ -258,6 +258,11 @@ STATIC mp_obj_t pyb_i2c_init_helper(const pyb_i2c_obj_t *self, uint n_args, cons
 /// initialised (it has the settings from the last initialisation of
 /// the bus, if any).  If extra arguments are given, the bus is initialised.
 /// See `init` for parameters of initialisation.
+///
+/// The physical pins of the I2C busses are:
+///
+///   - `I2C(1)` is on the X position: `(SCL, SDA) = (X9, X10) = (PB6, PB7)`
+///   - `I2C(2)` is on the Y position: `(SCL, SDA) = (Y9, Y10) = (PB10, PB11)`
 STATIC mp_obj_t pyb_i2c_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
     // check arguments
     mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);