Comments for Frank's Random Wanderings

Comment on STM32F2xx Digital Camera Interface (DCMI) by swenson

swenson — Sun, 08 Jan 2012 21:10:40 +0000

Thanks.

Comment on STM32F2xx Digital Camera Interface (DCMI) by frank

frank — Sat, 07 Jan 2012 16:20:42 +0000

I don't have any magic solutions - the pin mappings on these parts can get tricky, and for some packages certain functions may only be available on one pin. Which is the case here. You might want to think about using a small knife to, very carefully, cut those problem traces. Alternatively, if you have access to it, use a hot air desoldering station to remove the chips (like the CS43L22) that might cause a conflict. If you haven't done so already, posting your question over at the STM32F4Discovery forum might also be an idea. Good luck!

Comment on STM32F2xx Digital Camera Interface (DCMI) by swenson

swenson — Sat, 07 Jan 2012 14:53:58 +0000

Do you know if DCMI be used on the STM32F4Discovery board? It appears that there are pin conflicts that make it impossible.

PA4 – DCMI_HSYNC conflicts with CS43L22 – LRCK/AN1x
PA6 – DCMI_PIXCLK conflicts with LIS302DL – SDO
PB6 – DCMI_D5 conflicts with CS43L22 – SCL
PC7 – DCM!_D1 conflicts with CS43L22 – MCLK

The STM3240G-EVAL board appears to use the H and I pins to avoid these conflicts.

Any comments or suggestions? Thanks.

Comment on Do It Yourself Signal Generator Probe by David

David — Wed, 04 Jan 2012 06:00:03 +0000

Great idea! I think I’ll make one to replace my current SG connector which has alligator clips.

Comment on STM32F2xx SDIO SD Card Interface by Edward Keyes

Edward Keyes — Wed, 04 Jan 2012 02:12:08 +0000

Just wanted to say thanks a million for documenting these issues with the ST library code. I was tearing my hair out about the block-size problem: “Why am I only getting the first 8 bytes of each sector?!” Just the mere mention of that issue saved me a ton of debugging time…

Comment on STM32F2xx Processor Learnings by Thomas

Thomas — Thu, 15 Dec 2011 13:06:52 +0000

Thank you for your shared information. It is very helpful.

Comment on Atmel Xmega HD44780 LCD Support by frank

frank — Sat, 10 Dec 2011 16:39:37 +0000

Your best bet is to post your question over at http://www.avrfreaks.net/. Good luck!

Comment on STM32F2xx SDIO SD Card Interface by Memphis

Memphis — Tue, 15 Nov 2011 13:46:19 +0000

The biggest problem is that reference manual has too few informations about how to exactly do the read and write operations with DMA support.

The given examples are really for a start point but the production code must be totally rewriten by yourself (means the Utilities directory too!), only a library can be used as it is, but sometimes it needs a little fix too.

And also i am little bit suprised about SDIO, i expected more self work HW than making a bunch of code just for a simple read and write operations. I comapred the SPI library for SD card with the SDIO and it looks that simple SPI are written with less code, which doesnt make sense :-/

Comment on Atmel Xmega HD44780 LCD Support by Sudhir Owthar

Sudhir Owthar — Mon, 14 Nov 2011 09:56:32 +0000

Hi Frank

I am trying to interface an HD44780 LCD to an XMega16 MCU. I Have followed all your instructions on this page but nothing is being displayed on the LCD. I am using an STK600 development board with DC power and USB for programming. I gave connected the LCD to the port pins on the development board and i am using a separate 5V regulated power supply for the LCD power. I have grounded the RW pin as per your instructions. Port A is being used for DATA and PortB as the control. I compiled the program using AVR-GCC on the following IDE’s: AVR Studio 5.0 and AVR Studio 4.18. The program builds and compiled with o errors. I used all of your code snippets to test the LCD but nothing is being written.

Please help me with this problem. I do not understand what I am doing wrong. Your help will be greatly appreciated.

Thank you for a great webpage and all your time and effort.

Sudhir owthar

Comment on STM32F2xx Digital Camera Interface (DCMI) by frank

frank — Sun, 13 Nov 2011 16:42:20 +0000

A lot of CMOS sensors are compatible with the DCMI. The DCMI is a pretty flexible port. You’ll need to read the documentation (datasheets etc) for both the DCMI and the sensor you’re interested in to confirm they’re compatible with each other. There’s no avoiding the reading – you’ll need to do it (in great detail) to program the DCMI and image sensor anyway. I looked at the product brief for the OV7670 and at first glance, it looks like it might be ok – I didn’t see any immediate obvious problem. Take a look at some of ST’s reference designs, for example the STM3240G-EVAL board, for sample schematics on how to connect up an image sensor.