Tian Tian Xiang Shang - Another Hardware

Now, initial TTXS is working well.

I'm porting TTXS to the board named Nucleo-32 L432, which is smaller. There used to be a single Nucleo board, which was STM32 Nucleo F103. It seemed that when the smaller one came, now, there are two different series, smaller Nucleo-32 and larger Nucleo-64, with various chips.

The structure is similar. It has a target chip, and ST-Link/V2-1 for flashing/debugging. It is all-in-one development board.

Nucleo-32 L432 has STM32L432 (instead of STM32F103 on Nucleo-64 F103). Its USART has capability to support inversed mode (polarity 0 as H and the serial order MSB to LSB).

TTXS by Nucleo-32 L432

Another Reference Hardware

Nucleo-32 L432 is another reference hardware for TTXS.

Just like Nucleo-64 F103, I don't use any driver IC for smartcard; STM32L432 is directly connected to a smartcard connector. This is OK for experiment, because most smartcards support +3V3 voltage these days.

This time, I even don't put a resistor, using internal pull-up resistor.

I intend to use this hardware with SIM card form factor. So, the connector is:

  • Yamaichi Electronics: FMS006-2610-0

Circuit (just connections of wires)

Smartcard Pinout

Here is a top view of Yamaichi FMS006-2610-0 pinout:

/---------+---------\   1: Vcc (C1)
| C1      |     C5  |   2: GND (C5)
+-----\   |   /-----+   3: RST (C2)
| C2   +--+  +  C6  |   4: Vpp (C6)
+------|     |------+   5: CLK (C3)
| C3   +--+--+  C7  |   6: I/O (C7)
+-----/       \-----+   7: SW1
      SIM card          8: SW2 card detect

Pin 7 is connected to Pin 2, so that card detection can be done with 0.

Use of Connector of Nucleo-32 L432

We use pins from CN3 and CN4 connector.

  • PA0: card insertion detect (0 when detected)
  • PA3: Vcc
  • PA4: Vpp
  • PA1: RST
  • USART1_TX (PA9): I/O
  • USART1_CK (PA8): CLK
  • USB DM PA11: USB cable D-
  • USB DP PA12: USB cable D+
  • CN3 4 (GND): USB cable GND (No connection USB cable Vbus)

Power is sourced from ST-Link/V2-1's USB Vbus.


I ported Chopstx to STM32L432, although FPU/DSP is not supported (yet).