Developing for the Cerb40

I’m trying to gather the list of development tools that are required for Cerb40 development (including the RLP stuff). I’ve noticed a few names go by on the forums but does anyone have a complete list?

What do you mean? To program it without NETMF? You can use any ARM tool and there many many of them

@ Gus, I noticed that the Cerb40 chip isn’t just a regular old micro controller, but in fact a DSP! It has a I2S bus as well as DSP functions, is that correct? I’ve seen it mentioned on the forums the name of the tool that is used to develop the framework for the Cerb, however I am unable to remember it’s name.

Keil MDK and ARM RVDS can be used and GCC in future as well.

The processor is cortex-m4f so yes it is has floating point and DSP.

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It will be another week till I get my Ceb40, can you state the exact chip number that the Cerb40 uses?

It’s the STM32F405RGT6. This means:
[ul]F405 - Cortex-M4, no ethernet or DCMI
R - 64 pins
G - 1024k flash memory
T - LQFP package
6 - -40c to 85c[/ul]

The STM32F405xx/STM32F407xx share reference manuals and datasheets. The technical documentation you need is here: GHI Electronics – Where Hardware Meets Software

As an aside, I now know why Oberon didn’t use the built-in ethernet MAC. The chip doesn’t have one, it’s not available in devices with less than 100 pins!

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(I guess another week is actually tomorrow God’s willing)

Thanks much guys.

Another development tool that is available is the CooCox CoIDE. When used with the arm-none-eabi-gcc-4_6 tool chain it provides a full development environment for the STM32F4 chips. The IDE and toolchain are totally free. In addition, if you purchase a STM32F4DISCOVERY development board (available from Mouser for ~$15) you can use the on-board ST-LINK debugger to program/debug the code on any SWD compatible STM32 board (i.e. Cerb40).


Well the thing showed up today; wow it’s small. the profane amount of power that this thing has for such a small size that is now hobby level, has to be another milestone in computing.

[Edit]Added photo[/Edit]


That’s where “tiny” stands for :slight_smile:

I know that I can solder on a 3.3 v regulator on the bottom to get power from the USB client port or I can provide the power directly as well. Does this mean that I can do both?

So after admiring the handy work of this board I just had 1 tinnie tiny suggestion: a power led would have been nice! You see a have a tendency to hook up stuff for the first time and blow them. Knowing that the little green light on the board should be shining is of great comfort to me.

The Cerb40 is meant mostly as a permanent installation, where a power LED is just a waste of energy. If you want a power LED, may I (humbly) suggest a Cerb40 prototyping platform:

@ godefroi - thanks for the pitch. you are indeed humble. for those that may not know, godefroi was the hardware design effort behind this board. I’m just the guy that gets them fabbed and sells them. I did offer a second set of eyes and a feature suggestion or two, though :slight_smile:

@ kurtnelle - I do have some available if you are interested. Bonus feature - it has the LED you are looking for.

Huh? We use an STM32F407VG on both mainboards, which indeed has 100 pins, and we [em]do[/em] use its integrated Ethernet MAC…

For an overview, maybe this document would be interesting:

You can also take a look at the schematics of the Ethernet mainboard; there is no external Ethernet MAC there, just a PHY chip:

I would at least have preferred an unpopulated led on the board so that I could have options. Debugging hardware is hard enough as it is without diagnostic leds. I’m loving this board though.

I didn’t realize that you were using the 100-pin packages when I wrote that. I think it’s great to use the built-in MAC, as I would expect costs to be lower and performance to be higher. Is that your experience?

Too early to say, we didn’t have the time yet to do real comparisons. I know that someone is working on benchmarks to compare different NETMF boards e.g. regarding how many HTTP requests they can handle per second, so hopefully we’ll soon know more.

Cuno, I noticed that someone (Oberon I believe?) contributed support for GCC 4.6.1 in the QFE2 version of the PK. I was wondering, does this support work for the STM32 port?

I´m searching for 2-3 hours in this Forum, if Cerb40 (and the new 4.2 SW) supports RLP programming.
Does anyone know?

All the examples for RLP I found in this forum are based on other HW boards, the links for downloading the
files which are necessary for programming in RLP (that one, I found) are broken (maybe because of changing
to GHI webpage, maybe GHI doesn´t want to support RLP on Cerb40, maybe RLP never was thought on Cerb40)?

So I ask myself, if RLP and Cerb40 is still available (or if it was available) - not that RLP only works on other boards …
(in that case I dont have to look for working RLP links …)

With regards, Michael