OLIMEX STM32-P405 User manual

STM32-P405 development board
USER’S MANUAL
Revision A, December 2015
Designed by OLIMEX Ltd, 2015
All boards produced by Olimex LTD are ROHS compliant

OLIMEX© 015 STM3 -P405 user's manual
D SCLA MER
© 015 Olimex Ltd. Olimex®, logo and combinations thereof, are registered trademarks of Olimex Ltd. Other product names
may be trademarks of others and the rights belong to their respective owners.
The in ormation in this document is provided in connection with Olimex products. No license, express or implied or
otherwise, to any intellectual property right is granted by this document or in connection with the sale o Olimex
products.
The hardware design of STM3 -P405 development board is considered propriety. The board's schematics are available in pdf
format. The original schematic and design files are not available to the public.
The part of the software written by Olimex is released under GPL. However, note that the examples that we distribute are
based on the libraries and projects released by IAR Systems. Make sure that you are acquainted with the license agreement of
IAR Embedded Workbench before using, publishing, or distributing any code based on the software released by Olimex.
It is possible that the pictures in this manual differ from the actual appearance of the latest revision of the board.
The product described in this document is subject to continuous development and improvements. All particulars of the product
and its use contained in this document are given by OLIMEX in good faith. However all warranties implied or expressed
including but not limited to implied warranties of merchantability or fitness for purpose are excluded. This document is
intended only to assist the reader in the use of the product. OLIMEX Ltd. shall not be liable for any loss or damage arising
from the use of any information in this document or any error or omission in such information or any incorrect use of the
product.
This evaluation board/kit is intended for use for engineering development, demonstration, or evaluation purposes only and is
not considered by OLIMEX to be a finished end-product fit for general consumer use. Persons handling the product must have
electronics training and observe good engineering practice standards. As such, the goods being provided are not intended to be
complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including product
safety and environmental measures typically found in end products that incorporate such semiconductor components or circuit
boards.
Olimex currently deals with a variety of customers for products, and therefore our arrangement with the user is not exclusive.
Olimex assumes no liability for applications assistance, customer product design, software performance, or infringement of
patents or services described herein.
THERE IS NO WARRANTY FOR THE DESIGN MATERIALS AND THE COMPONENTS
USED TO CREATE STM32-P405. THEY ARE CONSIDERED SUITABLE ONLY FOR STM32-
P405.
Page of 31

OLIMEX© 015 STM3 -P405 user's manual
Table of Contents
DISCLAIMER ...............................................................................................................................................
CHAPTER 1 OVERVIEW ............................................................................................................................ 5
1. Introduction to the chapter .................................................................................................................... 5
1.1 Features ............................................................................................................................................... 5
1. Target market and purpose of the board .............................................................................................. 6
1.3 Similar boards ..................................................................................................................................... 6
1.4 Document Organization ...................................................................................................................... 6
CHAPTER : BOARD DESCRIPTION ....................................................................................................... 7
.1 Layout (top view) ................................................................................................................................ 7
. Prototype area pinout (top view) ......................................................................................................... 8
CHAPTER 3 SETTING UP THE STM3 -P405 BOARD ............................................................................ 9
3. Introduction to the chapter .................................................................................................................... 9
3.1 Electrostatic warning ........................................................................................................................... 9
3. Requirements ....................................................................................................................................... 9
3. .1 Hardware requirements ................................................................................................................ 9
3. . Software requirements ............................................................................................................... 10
3.3 Powering the board ............................................................................................................................ 11
3.4 Programming the board ..................................................................................................................... 11
3.4.1 Using JTAG debugger ............................................................................................................... 11
3.4. Using USB cable and bootloader software ................................................................................ 11
3.4.3 Using RS 3 cable and bootloader software ............................................................................. 1
3.5 Prebuilt software ............................................................................................................................... 1
CHAPTER 4 THE STM3 F405 MICROCONTROLLER .......................................................................... 13
4. Introduction to the chapter .................................................................................................................. 13
4.1 The STM3 F405RG features ............................................................................................................ 13
CHAPTER 5 CONTROL CIRCUITY AND HARDWARE MODULES ................................................... 15
5. Introduction to the chapter .................................................................................................................. 15
5.1 Reset .................................................................................................................................................. 15
5. Clocks ................................................................................................................................................ 15
5.3 Power supply circuit .......................................................................................................................... 15
CHAPTER 6 CONNECTORS AND PINOUT ............................................................................................ 17
6. Introduction to the chapter .................................................................................................................. 17
6.1 USB connector .................................................................................................................................. 17
6. JTAG/SWD debug connector ............................................................................................................ 17
6.3 CAN connector .................................................................................................................................. 18
6.4 UEXT connector ................................................................................................................................ 18
6.5 PWR_JACK connector ..................................................................................................................... 19
6.6 BAT_3V connector ............................................................................................................................ 19
6.7 RS 3 _ connector ........................................................................................................................... 0
6.8 SD/MMC card connector .................................................................................................................. 0
6.9 Extension pins and prototype area .................................................................................................... 1
6.4 Jumper description ............................................................................................................................ 1
6.4.1 BOOT memory select jumpers .................................................................................................. 1
6.4. RTS_E ........................................................................................................................................ 1
6.4.3 CTS_E ....................................................................................................................................... 1
6.4.4 R-T jumper ................................................................................................................................
6.4.5 CAN0_T ....................................................................................................................................
Page 3 of 31

OLIMEX© 015 STM3 -P405 user's manual
6.4.6 LED_E .......................................................................................................................................
6.4.7 USBP_E .....................................................................................................................................
6.4.8 WP_E jumper ............................................................................................................................
6.4.9 3.3V_MCU_E jumper ............................................................................................................... 3
6.5 Additional hardware components ...................................................................................................... 3
CHAPTER 7 BLOCK DIAGRAM AND MEMORY ................................................................................. 4
7. Introduction to the chapter .................................................................................................................. 4
7.1 Processor family block diagram ........................................................................................................ 4
7. Physical memory map ....................................................................................................................... 5
CHAPTER 8 SCHEMATICS ...................................................................................................................... 6
8. Introduction to the chapter .................................................................................................................. 6
8.1 Eagle schematic ................................................................................................................................. 6
8. Physical dimensions .......................................................................................................................... 8
CHAPTER 9 REVISION HISTORY AND SUPPORT ............................................................................... 9
9. Introduction to the chapter .................................................................................................................. 9
9.1 Document revision ............................................................................................................................ 9
9. Board revision ................................................................................................................................... 9
9.3 Useful web links and purchase codes ................................................................................................ 30
9.4 Product support ................................................................................................................................. 31
Page 4 of 31

OLIMEX© 015 STM3 -P405 user's manual
CHAPTER 1 OVERV EW
1. ntroduction to the chapter
Thank you for choosing this general-purpose development board designed and assembled by Olimex!
This document provides a user’s guide for the Olimex STM3 -P405 board. As an overview, this chapter
gives the scope of this document and lists the board’s features. A comparison between boards similar to
STM3 -P405 is presented. The document’s organization is then detailed.
The STM3 -P405 development board enables code development of applications running on the
microcontroller STM3 F405RG, manufactured by STMicroelectronics.
STM3 -P405 board is a medium-sized development board with a small prototype area. Using STM3 -
P405 you can explore the features of STM3 F4 family on budged. The board has everything necessary
for a large number of different applications: USB port for communication and powering; separate power
jack for powering; reset and oscillator circuits; JTAG port for programming and debugging; serial driver
and DE9 connector; UEXT expansion connector; prototype area; programmable LED; programmable
button and much more.
There are plenty of GPIOs available at the GPIO area which can be used to connect your additional
circuits.
1.1 Features
The board has the following list of features:
•MCU: STM3 F405RG ARM Cortex M4 in LQFP64 pacakge that operates up to 168 Mhz; with
10 4KB flash memory; (19 +4)kB SRAM; ×USB; ×CAN; x I C; 3×1 -bit ADC×16
channels; ×1 -bit DAC; ×UART; 3×SPI; 17 timers; with up to 51 GPIOs
•Standard JTAG (SWD) connector with ARM ×10 pin layout for programming/debugging with
ARM-JTAG
•USB type B connector
•User and RESET buttons
•User and power supply LEDs
•CAN driver and connector
•RS 3 driver and connector
•UEXT connector which allows easier hardware connection to different extension modules (like
MOD-IO , MOD-MAG, etc.)
•SD-MMC connector
•On-board voltage regulator 3.3V with up to 800mA current
•Single power supply: takes power from either the USB port or the power supply jack
•8 Mhz crystal oscillator
•3 768 Hz crystal and RTC backup battery connector
•Prototype area with 0.1" step for all uC ports
•PCB: FR-4, 1.5 mm (0.06 "), red soldermask, white silkscreen component print
•Dimensions: (100 × 90)mm ~ (3.9 × 3.5)"
Page 5 of 31

OLIMEX© 015 STM3 -P405 user's manual
1.2 Target market and purpose of the board
STM3 -P405 is a development board featuring a ARM Cortex-M4 microcontroller. The board can be
powered by a number of different sources. It can be programmed with a debugger via JTAG or SWD, or
alternatively with a cable via USB. The board has a lot of GPIO pins exposed.
The board is suitable for numerous tasks and situations. The power of ARM and the creativity of
OLIMEX come at the best price and the well-known quality.
Every ARM enthusiast would see STM3 -P405 as quite capable board for its low price.
1.3 Similar boards
The STM3 H405RG microcontroller is also present in two other Olimex-made boards – STM3 -H405
and STM3 -405STK.
•STM3 -H405 is a smaller and cheaper header board – it is a good choice if you want to embed
STM3 H405 in your own product or design. It is not recommended for initial evaluation of
STM3 H405RG since it lacks in peripherals and interfaces available.
•STM3 -405STK has a different set of peripherals compared to STM3 -P405 – micro SD card
interface with connector, mini USB, 84x48 BW display; microphone input with connector;
headphone output with connector; UEXT connector; two male extension headers. The board can
be powered by a 1.5V AA battery – there is a battery holder provided.
Another board, quite similar to STM3 -P405, is STM3 -P103; the board designs are almost identical –
the main difference is that STM3 -P103 uses STM3 F103RB.
If you are looking for a board with similar processor and Ethernet functionality take a look at STM3 -
E407 board. It uses STM3 H407ZG.
1.4 Document Organization
Each section in this document covers a separate topic, organized as follow:
–Chapter 1 is an overview of the board usage and features
–Chapter contains the board's layout
–Chapter 3 provides a guide for quickly setting up the board
–Chapter 4 describes the component that is the heart of the board: the STM3 F405 microcontroller
–Chapter 5 is an explanation of the control circuitry associated with the microcontroller to reset.
Also shows the clocks on the board
–Chapter 6 covers the connector pinout, peripherals and jumper description
–Chapter 7 shows the block diagram and the memory map
–Chapter 8 provides the schematics
–Chapter 9 contains the revision history, useful links and support information
Page 6 of 31

OLIMEX© 015 STM3 -P405 user's manual
CHAPTER 2: BOARD DESCR PT ON
In this chapter you will get acquainted with the main parts of the board. Note the names used on the board
differ from the names used to describe them. For the actual names check the STM3 -P405 board itself.
2.1 Layout (top view)
The picture below shows the top side of the board and highlights the most important parts.
Notice that all on-board jumpers are SMD type – in order to change the position of the jumpers you
would either need to cut between the pads of the jumper or solder the pads together.
The bottom view of the board is not shown since there is only one important component of the board at
the bottom – the SD/MMC connector. Note that it is a full-sized MMC connector.
Page 7 of 31

OLIMEX© 015 STM3 -P405 user's manual
2.2 Prototype area pinout (top view)
Below you would find the signals available at the male headers and the prototype area. Each pinhole of
the same row of the prototype area has the same signal available.
The picture also includes the positions of all connectors available at the top, all jumpers, the LEDs, the
buttons. Refer to chapter 6 for signal pinout of the rest of the connectors.
Page 8 of 31

OLIMEX© 015 STM3 -P405 user's manual
CHAPTER 3 SETT NG UP THE STM32-P405 BOARD
3. ntroduction to the chapter
This section helps you set up the STM3 -P405 development board for the first time.
Please consider first the electrostatic warning to avoid damaging the board, then discover the hardware
and software required to operate the board.
The procedure to power up the board is given, and a description of the default board behavior is detailed.
3.1 Electrostatic warning
STM3 -P405 is shipped in a protective anti-static package. The board must not be exposed to high
electrostatic potentials. A grounding strap or similar protective device should be worn when handling the
board to avoid electrostatic discharge.
In the package there is a bag with 4 rubber pads which can be placed in the holes near the corners of the
board. That way the board will be safe from short-circuiting on the bottom if placed on low-resistance
surface. The placement stability of the board will also increase.
3.2 Requirements
In order to set up the STM3 -P405 optimally you would need a hardware debugger tool and compatible
software tools. More detailed information may be found in the sub-chapters below.
3.2.1 Hardware requirements
- Standard ARM JTAG/SWD debugger – it can power the board and gives you the ability to debug your
code in real-time – to select the correct tool make sure that it is compatible with the software tools which
you are going to use during development. Also makes sure that the tool is compatible with the
STM3 F405 processor.
IMPORTANT: The board can be programmed using only a USB cable. However, it is a slow process –
this way of programming is not suitable for evaluation, research and development. Using the USB DFU
bootloader might be good idea only if you need to program the board once or twice.
It is not possible to use the RS 3 connector and cable for programming (via the chip's serial bootloader).
It is not implemented by hardware design.
Additional components can be acquired in order to increase the functionality of the board:
- USB cable with type A and type B connectors – in case you want to power the board from the USB port
of your personal conputer or, alternatively, if you want need to utilize the board's USB interface
- serial cable to interface the board's female DE-9 connector
- jumper wires – allow solderless access to the exposed pins; if you want to directly connect to the
extension headers use wires with a female connectors.
- power adapter with suitable connector capable of providing exactly 6V of DC voltage
- UEXT extension boards – such can be used to expand the features of the board
Page 9 of 31

OLIMEX© 015 STM3 -P405 user's manual
Some of the suggested items can be purchased by Olimex, for instance:
ARM-USB-TINY-H – high-speed OpenOCD ARM JTAG debugger
ARM-USB-OCD-H – high-speed OpenOCD ARM JTAG debugger with buffer protection
USB-A-B-CABLE – cable with USB type A and USB type B connectors at each end
RS232-CABLE – cable with male DE-9 connector at one side and female DE-9 connector at the other
JW-200x10-FM – ten jumper wires with female-male connectors
3.2.2 Software requirements
In order to change the code on the board you would need an ARM C compiler and debugger software, the
possible software options are:
- free open-source software: OpenOCD (all Olimex OpenOCD JTAG debuggers are supported in
OpenOCD)
- free software: CooCox IDE (all Olimex JTAGs are supported in CooCox)
- commercial software: EW-ARM from IAR Systems AB; CrossWorks from Rowley (all Olimex
OpenOCD JTAG debuggers are supported in IAR and Rowley Crossworks; note that our debugging tools
doesn't work in Keil MDK-ARM).
Refer to the table below for some guidance when choosing development tools.
Comparison table
Is it free or
commercial
Initial
struggle and
set-up time
STM32-P405
examples
pro ided by
Olimex
Is it open-
source
Does it work
with Olimex
OpenOCD
debuggers
Quality of
customer
support
OpenOCD Free Highest No Yes Yes Bad
CooCox IDE Free High No No Yes Mediocre
Rowley
Crossworks
for ARM
Commercial (free
time-limited
e aluation ersion)
Low No No Yes Good
Keil
MDK-ARM
Commercial (free
size-limited
e aluation ersion)
Low No No No Good
IAR EW
for ARM
Commercial (free
size-limited
ersion and free
time-limited
e aluation ersion)
Low Yes No Yes Good
It is a good idea to study the example that is provided by Olimex for your board. If you are not willing to
purchase the software just use the evaluation version initially.
Specifically, for STM3 -P405 Olimex provides only IAR EW for ARM examples. It is a good idea to
download the latest time-limited evaluation version.
Page 10 of 31

OLIMEX© 015 STM3 -P405 user's manual
3.3 Powering the board
The board can be powered in one of the following ways:
1) Using the JTAG or SWD debugger – the board gets powered via the 0-pin 0.1” step JTAG connector;
note that some tool might hold the board in RESET state – make sure to release the microcontroller from
RESET to be able to see the execution of your code
) Using USB cable – the board gets powered via the USB connector; the power is provided, typically, by
your computer's USB port
3) Using external power supply – in this case, the board gets powered via the VIN line – provide +6V DC
to pin (pad) named “VIN”; then connect the power supply's ground line to a pin (pad) named “GND”.
The board has BAT_3V connector which can be used to keep alive the RTC, external clock 3 kHz
oscillator and backup registers (through power switch) when VDD is not present. BAT_3V requires
voltage in the 1.65V – 3.6V range! The BAT_3V connector can not be used to fully power the board.
IMPORTANT: By default you can have either battery or external power supply connected (via the 6V DC
barrel jack). If you connect both you might damage the board or the battery. If you need to keep the
physical connection consider changing the default (closed) position of the BAT_E jumper!
3.4 Programming the board
The programming of the board is also fairly straight forward (unlike the software development for the
board).
3.4.1 Using JTAG debugger
This is the recommended method of changing the software of the board. This is fairly simple from
hardware point of view – simply plug the male 0-pin JTAG connector of your hardware tool to the 0-
pin female JTAG connector of STM3 -P405.
Refer to the documentation of your debugger and also to the documentation of the software of choice on
instructions how to set the whole development environment.
3.4.2 Using USB cable and bootloader software
The board can be programmed without a debugger tool. In this case you only need a personal computer
that is able to run Windows software and an USB cable.
STM3 -P405 has a built-in USB DFU bootloader that allows such programming.
Programming STM3 -P405 via the bootloader is a slow process that requires the re-configuration of
SMD jumper. It is not recommend for initial evaluation, research and development (use any ARM JTAG
debugger instead). Using the bootloader might be good idea only if you need to program the board once
or twice.
How to do it:
1. Change the position of one of the boot SMD jumpers – B0_H/B0_L (the bottom one). By default it is
set to position B0_L – you need to change it to B0_H. This requires soldering.
Page 11 of 31

OLIMEX© 015 STM3 -P405 user's manual
. After the adjustment is done you can connect to the DfuSe software released by STM. It available for
download from STM's official web-site. Search for “STSW-STM3 080”.
3. Install the software and run it.
4. Connect the board via the USB cable to the personal computer.
5. The board should now be recognized in the software. The bootloader application provided by STM3 is
a bit strange. It works only with dfu files. To upload other binary files (hex, bin, s19) you would need to
use additional converter tool (“DFU File Manager”; it converts hex, bin, s19 to dfu and vice versa). I
highly recommend you to read carefully the document about the usage of the Dfuse called “Getting
started with DfuSe USB device firmware upgrade”. Search for “UM041 ”.
6. Note that once you've uploaded the software you would need to change the jumpers back to the original
position – else the bootloader would start every time and the user program (typically stored in the flash
memory) would not execute.
3.4.3 Using RS232 cable and bootloader software
The access to the serial bootloader is not implemented in STM3 -P405. You can't access the bootloader of
STM3 F405 via the serial interface.
3.5 Prebuilt software
Upon powering the board the PWR LEDs should turn on and the STAT LED should blink fast 10 times.
The board comes with the software which was downloaded and used during the testing of the board. This
software and its source code could not serve any purpose to the customer, who purchased the board, since
it requires additional custom hardware. That is why there is a more meaningful example available for
download at the web-page of the board. Please download and extract the following archive which
contains the recommended initial demo:
https://www.olimex.com/Products/ARM/ST/STM3 -P405/resources/STM3 -P405_example.zip
Note that the demo can opened and compiled out-of-the-box ONLY with IAR Embedded Workbench for
ARM. You can get a free code-size or time-limited evaluation version of IAR EW for ARM from their
official web-site (requires registration). Refer to the “readme.txt” file inside the archive for more
information.
There is also a separate CAN-specific demo available for download from this link:
https://www.olimex.com/Products/ARM/ST/STM3 -P405/resources/STM3 -P405-CAN-DEMO.zip
Again refer to the “README.txt” inside of the archive for more information about the demo.
Page 1 of 31

OLIMEX© 015 STM3 -P405 user's manual
CHAPTER 4 THE STM32F405 M CROCONTROLLER
4. ntroduction to the chapter
Some of the details about the main processor in the design of STM3 -P405 (STM3 F405RG) are
mentioned in this chapter. The information is a modified version of the datasheet provided by its
manufacturers from ST.
It is highly recommended to refer to the original datasheet which might be downloaded from the ST's
official web-side.
4.1 The STM32F405RG features
STM3 -P405 uses STM3 F405RG – a microcontroller designed and manufactured by
STMicroelectronics. It has the following features that distinguish it from the rest of the family:
Core: ARM 3 -bit Cortex™-M4 CPU with FPU, Adaptive real-time accelerator (ART
Accelerator™) allowing 0-wait state execution from Flash memory, frequency up to 168 MHz,
memory protection unit, 10 DMIPS/1. 5 DMIPS/MHz (Dhrystone .1), and DSP instructions
Memories
1 Mbyte of Flash memory
19 +4 Kbytes of SRAM including 64-Kbyte of CCM (core coupled memory) data RAM
Flexible static memory controller supporting Compact Flash, SRAM, PSRAM, NOR and
NAND memories
LCD parallel interface, 8080/6800 modes
Clock, reset and supply management
1.8 V to 3.6 V application supply and I/Os
POR, PDR, PVD and BOR
4-to- 6 MHz crystal oscillator
Internal 16 MHz factory-trimmed RC (1% accuracy)
3 kHz oscillator for RTC with calibration
Internal 3 kHz RC with calibration
Sleep, Stop and Standby modes
VBAT supply for RTC, 0×3 bit backup registers + optional 4 KB backup SRAM
3×1 -bit, .4 MSPS A/D converters: 4 channels and 7. MSPS in triple interleaved mode
×1 -bit D/A converters
General-purpose DMA: 16-stream DMA controller with FIFOs and burst support
Up to 17 timers: up to twelve 16-bit and two 3 -bit timers up to 168 MHz, each with up to 4
IC/OC/PWM or pulse counter and quadrature (incremental) encoder input
Debug mode
Serial wire debug (SWD) & JTAG interfaces
Cortex-M4 Embedded Trace Macrocell™
114 I/O ports with interrupt capability
Up to 15 communication interfaces
3 × I C interfaces (SMBus/PMBus)
4 USARTs/ UARTs (10.5 Mbit/s, ISO 7816 interface, LIN, IrDA, modem control)
3 SPIs (37.5 Mbits/s), with muxed full-duplex I S to achieve audio class accuracy via
internal audio PLL or external clock
 × CAN interfaces ( .0B Active)
Page 13 of 31

OLIMEX© 015 STM3 -P405 user's manual
SDIO interface
Advanced connectivity
USB .0 full-speed device/host/OTG controller with on-chip PHY
USB .0 high-speed/full-speed device/host/OTG controller with dedicated DMA, on-chip full-
speed PHY and ULPI
10/100 Ethernet MAC with dedicated DMA: supports IEEE 1588v hardware, MII/RMII
8- to 14-bit parallel camera interface up to 54 Mbytes/s
True random number generator
CRC calculation unit
96-bit unique ID
RTC: subsecond accuracy, hardware calendar
For comprehensive information on the microcontroller visit the ST’s web page for a datasheet.
At the moment of writing the microcontroller datasheet can be found at the following link:
http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00037051.pdf
Page 14 of 31

OLIMEX© 015 STM3 -P405 user's manual
CHAPTER 5 CONTROL C RCU TY AND HARDWARE MODULES
5. ntroduction to the chapter
Here you can find information about reset circuit and quartz crystals locations, the power supply circuit is
discussed.
5.1 Reset
The reset circuit is connected to pin #7 (NRST) of the STM3 F405RG microcontroller. STM3 -P405's
reset circuit includes R8 (10 kΩ), C 8 (100nF) and a RESET button.
The RST signal can be found at an extension pin and has own row of pin holes at the prototype area –
check for the pin named “RST”.
The reset is also available at pin #15 of the JTAG connector. Furthermore, you can connect RST and
TRST of the JTAG together if you close the SMD jumper “R-T”.
The reset signal can be connected to pin # 5 of the EXT1 header.
5.2 Clocks
There are two quartz crystals available on the board:
8 MHz quartz crystal Q1 is connected to pins 5 and 6 of the ARM microcontroller.
Quartz crystal Q is a 3 768Hz RTC and it is connected to microcontroller's pins 3 and 4.
5.3 Power supply circuit
The power supply circuit of STM3 -P405 allows the board to be fully powered from four locations.
1) The recommended location to power the board is the “PWR” barrel jack. You should provide
between 6V DC and 1 V DC. There is a diode rectifier at this power input so you can also power
the board with 5V AC to 9V AC. The barrel jack is center positive.
) The most used interface for powering is the USB type B connector. It works at +5V DC.
3) The board can also be powered via the on-board JTAG connector. In that case the board
receives +3.3V DC from the debugger tool.
4) The board can be fully powered from the extension pins (or the pin holes at the prototype area).
The best location to power the board would be the two pins at the bottom of the column of male
pins – provide between +6V DC and +1 V DC to the VIN pin. Double check the pin locations
before providing the power. Important: VIN signal line is connected after the diode rectifier – do
not provide negative voltage at VIN! Do not provide AC voltage to VIN!
If you want to use a back-up battery consider using the BAT_3V connector. It works with batteries
providing voltage in the (1.65 – 3.6)V range. This VBAT pin allows to power the device VBAT domain
Page 15 of 31

OLIMEX© 015 STM3 -P405 user's manual
from an external battery, an external supercapacitor, or from VDD when no external battery nor an
external supercapacitor are present. VBAT operation is activated when VDD is not present. The VBAT
pin supplies the RTC, the backup registers and the backup SRAM.
The board consumes around 0. 5W (e.g. 0.04A at 6V) with both LEDs on. You can enable one of the low-
power modes to reduce the consumption.
By default, if you have successfully powered the board its PWR LED would turn on. The STAT LED
would blink 10 times. In case you you have modified the software (or if you have changed the positions
of the jumpers responsible for the boot location) the STAT LED might not turn on at all since it is
initialized by the code loaded on the flash memory of the board.
The red LED should always turn on upon powering. Note that it is possible to have the PWR LED on
even if there isn't enough power for proper operation of the board and all the peripherals currently
connected.
Page 16 of 31

OLIMEX© 015 STM3 -P405 user's manual
CHAPTER 6 CONNECTORS AND P NOUT
6. ntroduction to the chapter
In this chapter are presented the connectors that can be found on the board all together with their pinout
and notes about them. Jumpers functions are described. Notes and info on specific peripherals are
presented. Notes regarding the interfaces are given.
6.1 USB connector
The USB type B connector allows you to access the USB functionality of STM3 -P405. This connector is
can be used to power the board. The connector is sturdy and typically lasts much longer during extensive
use compared to the USB mini or USB micro connectors.
Note the DFU bootloader uses the USB port.
The signals follow the familiar and standard USB pattern:
USB Type B connector
Pin # Signal name
1+5V_USB
2USBDM
3USBDP
4GND
6.2 JTAG/SWD debug connector
The board can be debugged from the 0-pin JTAG connector either by a debugger with compatible
connector. The on-board JTAG connector has 0.1” step of its pins. Below is the table with the signals of
the JTAG. This interface can be used with the Olimex's OpenOCD debuggers. It is also compatible with
most of the ARM debuggers available on the market.
JTAG/SWD debug connector
Pin # Signal name Pin # Signal name
13.3V 23.3V
3TRST 4GND
5TDI 6GND
7TMS 8GND
9TCK 10 GND
11 GND 12 GND
13 TDO 14 GND
15 RST 16 GND
17 GND 18 GND
19 GND 20 GND
Page 17 of 31

OLIMEX© 015 STM3 -P405 user's manual
6.3 CAN connector
The available CAN interface is compliant with the .0A and B (active) specifications with a bitrate up to
1 Mbit/s. The on-board CAN interface uses CAN bus transceiver SN65HVD 30. The transceiver itself is
connected to the main microcontroller's pins 61 (port PB8) and 6 (port PB9).
CAN connector
Pin # Signal name
1 GND
CANL
3 CANH
The CAN interface behavior can be influenced by the two jumpers CAN0_T and CNTRL/HS.
6.4 UEXT connector
STM3 -P405 board has UEXT connector and can interface Olimex's UEXT modules. UEXT is a board to
board connector which supports three serial communication interfaces – I C, SPI and RS 3 . There is
also a +3.3V output line and GND.
For more information on UEXT please visit:
https://www.olimex.com/Products/Modules/UEXT/
UEXT connector
Pin # Signal name MCU pin #
1 3.3V -
GND -
3 USART1_TX 42
4 USART1_RX 43
5 I C1_SCL 58
6 I C1_SDA 59
7 SPI1_MISO 22
8 SPI1_MOSI 23
9 SPI1_SCK 21
10 SPI1_NSS 20
Note that the I C lines have 10k pullup resistors. SPI1_NSS also has a 10k pullup.
Page 18 of 31

OLIMEX© 015 STM3 -P405 user's manual
6.5 PWR_JACK connector
The power jack used is the typical one used by Olimex in most of our products – the DC barrel jack has
.0mm inner pin and 6.3mm hole. More information about the exact component might be found here:
https://www.olimex.com/wiki/PWRJACK.
You should provide either (6 – 1 )V direct current or (5 – 9)V alternating current. The required current
may vary depending on the peripherals connected to the board. Do not provide more than 1 VDC! Do not
provide more than 9VAC!
PWR_JACK connector
Pin # Signal name
1Power input
2GND
More info about the power supply can be found in chapter 4 of this manual.
6.6 BAT_3V connector
When using the battery connector keep in mind that it is an energy solution that wouldn't be able to power
the board and all the peripherals!
The board has BAT_3V connector which can be used to keep alive the RTC, external clock 3 kHz
oscillator and backup registers (through power switch) when VDD is not present. BAT_3V requires
voltage in the 1.65V – 3.6V range!
BAT_3V connector
Pin # Signal name
1VBAT
2GND
The pin polarity is also printed near the connector.
Page 19 of 31

OLIMEX© 015 STM3 -P405 user's manual
6.7 RS232_2 connector
The STM3 F405xx embeds four universal synchronous/asynchronous receiver transmitters (USART1,
USART , USART3 and USART6) and two universal asynchronous receiver transmitters (UART4 and
UART5). The RS 3 _ connector gives access to USART with throughput of 5. 5 Mbit/s.
By default RTS and CTS signals are disconnected. You can enable them by closing the jumpers RTS_E
and CTS_E.
The circuit for the serial connection includes the ST3 3 IC – it adjusts the external levels of USART to
suitable levels.
RS232_2 connector
Pin # Signal name
1Not connected
2USART2_TX
3USART2_RX
4Not connected
5GND
6Not connected
7UART2_RTS
8WAKE-UP (CTS)
9NC
6.8 SD/MMC card connector
SD/MMC slot is an SD card slot connector, located on the bottom of STM3 -P405. It works with the
“large” SD and MMC cards.
SD/MMC card connector
Pin # Connector signal name Wire name Microcontroller pin #
1CD/DAT3/CS SPI2_NSS 33
2CMD/DI SPI2_MOSI 36
3VSS1 VSS (GND) Any GND
4VDD SD_VCC1 Any 3.3V pin
5CLK/SCLK SPI2_SCK 34
6VSS2 VSS (GND) Any GND
7DAT0/DO SPI2_MISO 35
8DAT1/RES Pulled-up (held at logical 1) Not connected
9DAT2/RES Pulled-up (held at logical 1) Not connected
Additionally, there are the WP (write protect) and CP (card presence) switches that are responsible,
respectively, for sensing whether the card is locked for reading, and whether there is a card inserted.
You can manipulate the availability of WP and CP by manipulating WP_E and CP_E jumpers.
Disconnecting these jumpers would disable the WP and CP wires from the connector.
Page 0 of 31