Scot Kornak's ProtoBlog

A Pinout Spreadsheet for the STM32F4-Discovery

2012-01-05T08:47:00.001-07:00

ARM Cortex microcontrollers have a great number of peripherals. So many in fact that you won't be able to use many of them at the same time, except possibly on the highest pin count devices. The ST-Micro Discovery-F4 module provides six USARTs, two USB ports, three I2C ports, three SPIs, sixteen ADC channels, ethernet and more...
BUT you have to pick and choose which are connected to the 80 available GPIO pins.

The Discovery-F4 module has up to 10 alternate functions on some pins to allow you to choose whether to use the pin as GPIO or as a peripheral pin. Some functions are available on multiple pins. However, pin conflicts may mean you won't be able to use all of the peripherals you want at the same time.

I have created an Excel spreadsheet to help in the pin assignment process. The STM32-Discovery-F4 pinout spreadsheet lists the Discovery modules pin information along with the alternate functions available for each pin. This spreadsheet helps me to plan my projects by assigning pin names and rearranging the rows to group related pins. I have color coded the pin functions to help me see what functions are available on which pins.

The spreadsheet can be downloaded from http://kornak.ca/parts/stm32-discovery-f4/ .
Updates to this spreadsheet will be available in this directory when they are released. Revision 1.00 is named "Kornak-(STM32-Discovery-F4)-0001 Rev 1.00 Module Pinouts & Functions.xls"

There are three tabs/pages in the Excel workbook.

"Module Pins" lists the pins in the order found on the Discovery-F4 module headers
(two 50-pin DIL headers).
The "By Function" tab is intended to let designers group the pins according the functions that are being assigned for a project.
The "MCU Pins" tab sorts the pins by the MCU port names (port A, port B, etc.).

If you need more peripheral pins than can fit on a 100 pin STM32F407VGT6 microcontroller (LQFP100), ST-Micro also has versions available in 144 and 176 pin packages (see the STM32F4 family product selector). A 64 pin version is also available.

I would appreciate any comments or suggestions you may have on the spreadsheet or this blog. Please send them to kornak.busboard@gmail.com

Kornak Technologies provides embedded product development and manufacturing services including STM32 hardware and firmware development.

A Breakout Board for the STM32F4-Discovery

2011-12-22T12:12:00.001-07:00

This is the first in a series of articles about the STM32 family of ARM Cortex microcontrollers.

In this article I will show the breakout board I built for the STM32F4 Discovery module. It features two male DIL headers to easily attach jumper wires and two RS232 serial ports

It uses a BusBoard-3U prototyping board to connect the DIL male headers to the Discovery module. For RS232 interfaces I used ComBoard CB232F and CB232M modules to simplify wiring.

The STM32F4-Discovery Module

This fall STMicro gave away thousands of STM32F4 Discovery modules to promote their new ARM Cortex-M4 processor with floating point unit and DSP instructions. You can read about other STM32F4 key features in the STM32F4 press release.

http://www.st.com/internet/com/press_release/p3212.jsp

The STM32F4 Discovery module has many great features and it sells for only $18. It has a large memory size that makes this module very useful. The Discovery-F4 module has 1 Megabyte of Flash, which allows large programs to be written. It also has 192k of SRAM, which is huge for a microcontroller. RAM hungry firmware modules, such as file systems and TCP/IP stacks, are much more easily supported with lots of RAM.

Another great feature of the Discovery-F4 is that is has a built in SWD interface, which is the low-cost serial version of a JTAG debug interface. It provides the ability to program the MCU, and set breakpoints, inspect memory, or single-step through your program, which are a great help during debugging. It is a fantastic bargain to get these features in a low-cost development module. The F4’s predecessor modules, the Discovery-VL and Discovery-L, also provide the on-board SWD debug interface.

The STMicro support page for the Discovery-F4 module describes other features of the Discovery-F4 module and provides links to the firmware libraries.

http://www.st.com/internet/evalboard/product/252419.jsp

Breakout Headers
The Discovery-F4 module has two 50-pin DIL (dual in-line) headers, called P1 and P2, to connect to the processor pins. You could turn the module upside down and connect directly from the pins to a breadboard with male-female jumper wires. I wanted to make my connectors more permanent with soldered connections for the serial port modules.

The Discovery-F4 bottom male headers have long tails that protrude from the upper side of the PCB. These are long enough to make great test points to connect a scope probe to. However, they are not long enough to securely connect a female socket jumper wire.

To add two 50-pin expansion headers, I used a BusBoard-3U prototyping board. The Discovery-F4 module plugs into two Tyco 50-pin sockets. The BusBoard zig-zag pattern connects two 50-pin male headers to the female sockets, pin-to-pin, without the need to add any wires. In the photo below you can see how the DIL header pins get connect 1 to 1, 2 to 2, etc. (click to enlarge).

The BusBoard pattern has two sets of conductors on each row, one carry the left pin signal and one carrying the right pin signal. These carry the Discovery-F4 signals past the male headers and allow other parts to connect to the signals, such as the serial port interfaces on this project. The two sets of conductors are made visually distinct by using wide pads for one and narrow pads for the other. A hole on side of the board marks the wide pads when viewing from the top side.

I cut all the tracks on the BusBoard in the middle to separate the left connector track from the right connector tracks. It is easiest to cut the narrow tracks. I used the soldering iron tip to heat up the cut track segments and push them off the board. They slide right off once heated enough. (Hint: Use an old tip to avoid removing the plating from your good soldering iron tip). The cut tracks have red marker on them in the following photo to make them more visible. Some tracks between the ComBoard pins and the DIL header needed to be cut as well.

I had to add a red wire to carry the +5V power from the right side to the serial interface modules on the left. If I hadn’t cut all the tracks, this could have been avoided. Notice the two wire jumpers to the left and right of the red wire. These connect the narrow and wide tracks so it is carrying +5V power on both tracks in that row.

If you don’t need the 50-pin headers, a PR2H3U protoboard with 2-holes per strip may be preferable for a baseboard to provide simpler connections. The Discovery-F4 header pins would each be on separate pads, but the inner connections would need to be routed around the headers or wires added underneath.

RS232 Interfaces

I added two RS232 serial ports using ComBoard modules connecting to USART2 and USART3. I could have connected to USART1, but those pins are also used for the on-board USB-OTG. I did not want to use them to leave the option to use USB for future projects.

USART2 connects to a PC serial port so I used a ComBoard-232F module for a DCE port. USART3 uses a ComBoard-232M module for a DTE port, which will connect to a GPS module.

The following pins were used:

P1.13 PA3-USART2-RX

P1.14 PA2-USART2-TX

P1.40 PD8-USART3-TX

P1.41 PD9-USART3-RX

I decided to solder the ComBoard modules down to permanently attach them. I could have used a 10x1 SIL socket to make them changeable. There are 2-pin mounting holes (on the 0.1" grid) at the front of the module that allow it to be securely soldered down.

Breadboard Connections

The 50 pin headers make it easy to connect to a breadboard for experimentation. Male-female jumper wires provide reliable connections that are easy to reconfigure.

This photo shows a RS485 interface module connected to UART4.

Parts

The following table has the manufacturer part numbers for the parts mentioned in this article.

BusBoard-3U BusBoard BB3U Mouser Part#854-BB3U

ProtoBoard 2-Hole BusBoardPR2H3U Mouser Part#854-PR2H3U

80-pin DIL Header Tyco4-103186-0 Mouser Part#571-41031860

or Tyco 9-146256-0 Mouser Part#571-9-146256-0

(break 80 pin headers to the get theneeded 50 pin headers)

50-pin DIL Socket Tyco2-534998-5 Mouser Part#571-25349985

or Tyco 7-534998-5 Mouser Part#571-7-534998-5

Discovery-F4 Module STM32F4DISCOVERYMouser #511-STM32F4DISCOVERY

Discovery-VL Module STM32VLDISCOVERYMouser #511-STM32VLDISCOVERY

Discovery-L Module STM32L-DISCOVERY Mouser #511-STM32L-DISCOVERY

ComBoard CB232F PCB-232F (bare PCB) Amazon.com/PCB-CB232F

ComBoard CB232M PCB-232M (bare PCB) Amazon.com/PCB-CB232M

ComBoard CB485RJ PCB-485 (bare PCB) Amazon.com/PCB-CB485

400point Breadboard BusBoardBB400 Mouser Part # 854-BB400

I would appreciate any comments or suggestions you may have. Please send them to kornak.busboard@gmail.com (my Kornak Technologies/BusBoard Prototype Systems customer service email address).

Introducing the AVR-3U Dev Board for the ATmega1284P

2011-03-11T14:04:00.054-07:00

BPS has created a development board for 40 pin AVR microcontrollers. All the interfaces are brought out to various connectors to easily hook up to accessory boards and peripheral ICs.

We wanted the following features for the board:

All thru-hole construction for easy assembly
Easy port connections to breadboards for prototyping
2 serial ports. Lots of memory (> 32k).
JTAG connector for debugging

Some of the other features of the board are:

all headers are on a 0.1" grid to allow accessory proto-boards to span multiple connectors if needed
the power input connector can be a coaxial barrel connector, a 2-pin terminal block, or a MTA-100 connector or 0.1" spacing header
LCD displays can be connected using 1x16, 2x7 or 2x8 connectors.

Atmel offers microcontrollers with many memory sizes in the same 40-pin pinout. Therefore it is possible to use the AVR1284-3U board with 64k, 32k, and 16k microcontrollers to save money. A list of compatible part numbers and memory sizes is shown later in this article.

This photo shows some of the key board features:

Each port connector has +5V power, ground, and the 8 port bits. A DIL16-to-DIP16 ribbon cable can be used to carry the signals, power, and ground to a breadboard. The DIP16 connector on the ribbon cable plugs directly into the breadboard. There are 6 uncommitted lines on the headers if you want to add additional signals to the ribbon cable.

The AVR1284-3U board uses removable UART interfaces called ComBoards. It is easy to switch between different connectors and interface types. Presently there are modules for RS323-DCE (DB9F), RS232-DTE (DB9M), and RS485 interfaces. The RS485 interface can use RJ45 jacks for CAT-5 cable or a terminal block. We will be adding USB and other module options in the future.

There are 4 different DIP40 AVRs that can be used with this board depending on how much memory you want:
    ATMEGA164PA-PU, 16k Flash, 1K SRAM, 512 EEPROM
    ATMEGA324PA-PU, 32k Flash, 2K SRAM, 1K EEPROM
    ATMEGA644PA-PU, 64k Flash, 4K SRAM, 2K EEPROM
    ATMEGA1284P-PU, 128k Flash, 16K SRAM,4K EEPROM

All parts feature 2 USARTS, 1 two-wire interface (TWI), JTAG debug, in-system programming (ISP), 8 channel 10-bit ADC, 20 MHz max. clock, and 1.8 to 5.5 Volt operation. All parts have two 8-bit timers and a 16-bit timer, except that the 128k part has two 16-bit timers.

The 'P' in the part number is for PicoPower, which means the chip can be operated at low voltages and set up to draw minimal amounts of power.

Either P or the PA version of the 16k, 32k, or 64k parts can be used. The PA parts use a smaller die size and are slightly cheaper. There isn't a PA version of the 128k part yet.

The AVR1284-3U development board will be available as a bare PCB with a parts list, a parts kit (solder it yourself), and a fully assembled board.

Please send your comments and suggestions for AVR dev boards to skornak@gmail.com

Introducing Solderable PC BreadBoards

2010-10-20T08:46:00.006-06:00

A solderable PC breadboard is a prototyping printed circuit board (PCB) with a connection pattern the same as a solderless breadboard (plug-in breadboard). This article describes the solderable PC breadboards available from BPS.

Many electronics hobbyists are familiar with using breadboards to build and test circuits. Breadboards allow circuits to be quickly built and modified as needed, and they are reusable. However, breadboard circuits aren’t very rugged. Movement or vibration can easily cause wires and parts to fall out.

Once a circuit is working, a more rugged, permanent circuit is often needed. Soldering the parts on a PCB protoboard makes the connections durable. Since PC breadboards have the same patterns as breadboards, it is easy to construct a soldered permanent circuit bases on the plug-in breadboard prototype.

PC breadboards come in various sizes to match the different solderless breadboards available. The most common sizes are the 300, 400, and 830 tie-point breadboards.

A PDF version of this article is available.
BPS-AN0002-Solderable_PC_BreadBoard.pdf

BPS Solderless & Solderable PC BreadBoards

BPS provides solderless breadboards and solderable breadboards in the most popular sizes.

BB300 – 300 tie-point BreadBoard	*Copy your circuit to* *SB300 and solder it!* SB300 Solderable PC BreadBoard (300 tie-points)
BB400 – 400 tie-point BreadBoard	*Copy your circuit to* *SB400 and solder it!* SB400 Solderable PC BreadBoard (400 tie-points)

Solderless BreadBoards

BB830 – 830 tie-point BreadBoard

BB830T – 830 tie-point BreadBoard

(Transparent ABS body
allows contacts to be seen)

Copy your circuit to BR1

and solder it!

BR1 Solderable PC BreadBoard

(830 tie-points)

2 Copying a Circuit

It is better to “copy” a circuit than to “move it” when going from solderless breadboard to a solderable PC breadboard. Purchase 2 sets of components, if that isn’t too expensive. Use the second set of components to build an identical circuit on the PC breadboard, referring to the circuit on the plug-in breadboard.

Copying a circuit is easier than moving it part by part because one can refer to the still working prototype. Copying the circuit in this manner allows you to compare the soldered board to the working original in case there are problems and it doesn’t work immediately. The two circuits can also then be tested and measured to ensure they are working identically.

3 Bonus Pads

A solderless breadboard has areas where there are no connection points, for example, down the centreline (under the plugged in ICs) and between the circuit area and the power strips.

Solderable PC BreadBoards often have extra pads in these otherwise unusable spaces called Bonus Pads.

If a PC board is being used for general-purpose use, these bonus pads can be used for mounting extra components, and they can me some parts easier to fit.

If a PC board is being used to transfer a circuit from a solderless breadboard, these extra pads may be ignored.

3.1 SB300 Bonus Pads

The SB300 vertical circuit connections are in the same pattern as those on a BB300 solderless breadboard.

The SB300 bonus pads are the two distribution strips running the length of the board as bonus pads (the pink tracks in the photo). They can be used to carry power or signals.

3.2 SB400 Bonus Pads

The SB400 bonus pads include the 2-hole pairs running along the centerline (the pads shown in blue). These pads allow a dual in-line (DIL) header to be installed if required for off-board signals.

The BB400 solder has the same vertical connections in the circuit area and the same 4 outer distribution strips as the SB400 solderable PC breadboard.

The SB400 has two extra distribution strips (shown in pink). They are located with spacing 0.1” from the circuit area to allow parts with that spacing to bridge the gap.

The outer two distribution strips are located 0.25” away from the circuit area, which is the same spacing as the BB400. The SB400 distribution strip holes line up with the column in the circuit area. This makes the board easier to use as a general-purpose proto-board. Note that this is different than the BB400, where the distribution strip holes are offset by 0.050” from the circuit area holes.

3.3 BR1 Bonus Pads

The BR1 bonus pads include the 2-hole pairs running along the centerline (the pads shown in blue above). These pads allow a dual in-line (DIL) header to be installed if required for off-board signals.

The BR1 is 0.6 inches wider than a breadboard. Two extra columns, 4 mounting holes, and some round pads are provided in the extra area (shown in red above).

The BR1 has two extra distribution strips (shown in pink above). They are located with spacing 0.1” from the circuit area to allow parts with that spacing to bridge the gap. Note that the outer two distribution strips are located on 0.1” centers from the circuit area, which is helpful for general-purpose use. The distribution strips on the BB830 solderless breadboard are positioned an additional 0.05 inch further outwards.

The BR1 distribution strips have extra holes not found on the BB830 breadboard. The BB830 solderless breadboard strips have groups of 5 holes and then a space with no hole. The BR1 strips have a hole every 0.1”. The distribution strips holes line up with the columns in the circuit area on both the BR1 and BB830/BB830T breadboards.

DIL (Dual In-Line) Header Installed On A Solderable PC Board

With the centerline bonus pads, it is possible to use a DIL header without cutting tracks.

4 Distribution Strip Spacing Differences

The distribution strip spacing on some solderable PC breadboards is slightly different than the solderless plug-in breadboards. This has been done to keep the holes on 0.1” spacing centers to make them more useful as general-purpose prototyping boards.

As mentioned in the Bonus Pads section, the SB400 strips are located the same distance from the centerline as on the BB400, but they are offset to line up with the circuit area columns.

The BR1 distribution strips are moved inwards slightly by 0.050” so that all of the holes on the board are on 0.1” centers.

5 Off-board Connections

Here are some suggestions for connecting power and other off-board signal connections to a solderable PC breadboard:

1. Use stranded 22 AWG wire for wire connections running off-board to other boards or devices. Solid 22 AWG wire will crack and break after being flexed many times. Stranded wire can be flexed more times.

2. Use a strain relief to keep the wire from flexing at the point where it is soldered. Solder will wick up stranded wire when it is soldered, and make it stiff and susceptible to cracking. Using a strain relief causes the wire to flex away from the solder joint, where it is more flexible.

3. Use headers or other connectors with removable plugs for off-board connections. This allows more rugged cables to be used, and worn out cables can be replaced.

6 BPS BreadBoard Datasheets

These datasheets are available from the BPS web site.

BB830 and BB830T - 830 tie-point BreadBoards - http://www.busboard.us/pdfs/BPS-MAR-BB830+BB830T-001.pdf

BB300 and BB400 - 300 and 400 tie-point BreadBoards - http://www.busboard.us/pdfs/BPS-MAR-BB300+BB400-001.pdf

BR1 Solderable PC BreadBoard - http://www.busboard.us/pdfs/BPS-MAR-BR1-001.pdf

SB400 Solderable PC BreadBoard - http://www.busboard.us/pdfs/BPS-MAR-SB400-001.pdf

SB300 Solderable PC BreadBoard - http://www.busboard.us/pdfs/BPS-MAR-SB300-001.pdf

7 Creative Commons License

This document is licensed under the Creative Commons “Attribution” License.

This license lets others distribute, remix, tweak, and build upon the work, even commercially, as long as they credit the author for the original creation. This is the most accommodating of licenses offered, in terms of what others can do with the works licensed under Attribution. http://creativecommons.org/about/licenses

Attribution — Attribution can be done with a link to http://www.busboard.us or the original document at http://www.busboard.us/pdfs/BPS-AN0002-Solderable_PC_BreadBoard.pdf

See the PDF document for details.

BreadBoard Internal Connections

2010-10-11T16:17:00.008-06:00

This article describes the internal connections for the BB300, BB400 and BB830 breadboards.

A BPS (BusBoard Prototype Systems) customer asked us what the internal connections were on the BB300 breadboard. I then realized that it isn't obvious to someone who is using breadboards for the first time how the internal connections are laid out.

The PDF datasheets for the BPS breadboards have now been updated with diagrams of the internal connections.

The datasheets can be found on the BPS web site:

BPS BB300 and BB400 Datasheet

BPS BB830 and BB830T (Transparent BreadBoard) Datasheet

Here are the internal connections for the BB300 breadboard with 300 connection points. The BB300 has a circuit area with 30 columns of connections points on top and 30 columns below. Each column has 5 electrically connected tie points. Breadboards are designed so that a DIP integrated circuit spans the gap along the center line when it is plugged in. Each IC pin then has it's own 5-hole column allowing wires or parts to be connected to it.

Here are the internal connections for a 400 connection point breadboard (the BB400). The BB400 is a BB300 breadboard with distribution strips added to the top and bottom. The breadboards are designed with interlocking clips so that they can be connected together to create a larger working area.

The distribution strips are usually used for power and ground. When only a single voltage is needed for power, I like to use the red strips for +5 Volts and the blue strips for ground. I connect the two red distribution strips with a wire and the two blue strips with a wire, so that easy connections to power and ground are available on the top and the lower areas. A 100uF or larger capacitor should be added where the power comes into the breadboard, and a few 100nF capacitors added along the distribution rails to filter the power to your circuit.

If a distribution strip isn't needed for power, it can be used to carry some signal that is needed in several places in your circuit.

The BB830 and BB830T (T=transparent) breadboards have 630 connection points in the middle circuit area plus four distribution strips with 50 connection points each.

Note that some a few 830 connection point breadboard from other vendors have a break in the middle of the distribution strips that you need to bridge with a wire to get a strip running the whole width.

BPS breadboards are high-quality breadboards with clear silkscreen legends. The contacts are rated for 50,000 insertions. Each breadboard has double sided adhesive tape on back so the breadboard can be attached to a surface. The BB830 and BB830T come with a metal back plate that can attached to the back if you aren't attaching the breadboard to a surface.

Memorize Romans 12:1+2

2009-11-27T05:45:00.008-07:00

A friend of mine had some cards he was using to memorize Bible verses. In it he had Romans 12:1 and 2 from the New English Bible (NEB) translation. I love the way the NEB has translated these verses.

Living Sacrifices
Rom.12:1
Therefore, my brothers, I implore you by God's mercy to offer your very selves to him; a living sacrifice, dedicated and fit for his acceptance, the worship offered by mind and heart.
Rom.12:1 (NEB)

Discerning God's Will
Rom.12:2
Adapt yourselves no longer to the pattern of this present world, but let your minds be remade and your whole nature thus transformed. Then you will be able to discern the will of God, and to know what is good, acceptable, and perfect.
Rom.12:2 (NEB)

I like using the Navigators method of memorizing verses in which you give each verse a title to help you recall it. That is why I added titles to the two verses above.

Here's a Navigators suggestion I found helpful.
When memorizing and practicing verses, recite the following:
    Title,
    Reference (Book chapter:verse),
    The Verse(s)
    Reference again
This helps us to recall the verse by the reference or the words.

Here is a short article from the Navigators on How to Memorize Scripture.
The Navigators also have some suggested verses to start memorizing.

"Why memorize Bible verses?", you may ask. The Discipleship Journal magazine archives has an article (registration required) called "Verses ‘R' Us: Eight Reasons Why Scripture Memory Isn't Just For Kids".
The sub-title is "Memorizing God's Word gives the Holy Spirit the power to lead, guide, challenge, and instruct us", which is a pretty good reason to start with.