PIC based serial data storage?

[badcockr]

OK guys,

I am *sure* someone must have implemented something similar and maybe you could point me in the right direction.

Many RC items that I have have a PC link that is serial data, or utilises an on-board serial-USB chip like the FDTI. (Schulze chargers, multimeter, Emeter e.t.c.). What would be nice is to not link it directly to a PC but hook up a 'widget' to the output port of the device and record the data to memory; i.e. log the data. If you like this could operate as a *big* buffer, then removed and attached to a PC DB9 serial port and the data read out later (not in the field).

Now I am sure this is not too complicated and easily accomplished with a PIC. Has someone made something similar?

Thanks

Rod

[Comatose]

Pic to an I2c serial eeprom is a piece of cake. Use a pic with a SSP and a UART and it pretty much writes itself.

I'll see if I can dig up some code snippets for you monday if no one gets someting to you sooner.

Also, some of the common flash cards have an SPI mode if you really really need a lot of space.

[badcockr]

Pic to an I2c serial eeprom is a piece of cake. Use a pic with a SSP and a UART and it pretty much writes itself.

I'll see if I can dig up some code snippets for you monday if no one gets someting to you sooner.

Also, some of the common flash cards have an SPI mode if you really really need a lot of space.

Thanks Comatose,

This is what I thought - the problem I have is that all my spare 'hobby' time is being taken up with software and measurement systems at the moment. Hence the question about whether someone else has done this (no point re-inventing the wheel).

Your code snippets would be useful; I can see that this would have application across many of the RC tools, chargers and meters currently available. The memory card interface could be useful.

Rod

[Albatross]

Check out these PICs and bits, very steep learning curve at a reasonable cost.

www.picaxe.co.uk

[darkith]

Never having used such devices, the question I have is about the application level protocol? Does each device use a custom piece of software on the PC, that would require reverse-engineering of a protocol? Or is it just a straight serial stream of raw data...

D.

[badcockr]

Never having used such devices, the question I have is about the application level protocol? Does each device use a custom piece of software on the PC, that would require reverse-engineering of a protocol? Or is it just a straight serial stream of raw data...
A straightforward stream of serial data is all that is required. Without exception the PC software will handle a block transfer in the same way as individual lines.

HTH

Rod

[lazy-b]

Yes, I've been looking for the same thing, saw one they use an MMC flash card using a pic controller and serial interface.

I was hoping somebody have also make the same thing use USB FLASH DRIVE, (need only 4 wire) I plan to use it for my DATA logging device.....my current DATA logging device is a old PC with a single floppy drive, no harddisk, its just capture all those data send by a serial device.

I hope somebody already made it, I just do not want to re-invent the wheel again.

Been thinking of using a FLASH ROM use in PC board its available in 256K x 8 bits (2MB) , 512K x 8 bits (4MB).....Flash ROM for PC BOARD is much cheaper and use PIC 16F877 for controller.

I2C serial eeprom is good, but its not big enought for my application....128MB FLASH DRIVE cost only less USD 20.....I guess with 128MB data logger, I do not have to clean-up data logger for 5 years.......current I am using a 1.44MB disk, I have to download and clean-up every month.

this is nice project: using MMC card to serial interface
http://www.compsys1.com/workbench/On_top_of_the_Bench/MMC_Project/mmc_project.html