Get data back out of the PicAxe

[Bayside888]

This has probably been dealt with in the forums, but I can't find it so far. I need to have the PicAxe (28X2) make measurements and store data. Then, I need to plug in a laptop and download the data. Not that it really matters, but it would be a series of three numbers (each with 4 decimals, so word size). Probably about 1500 points or 1500 X 3 = 4500 words or 4500 X 2 = 9000 8bit bytes.

I can store the data in a serial EEprom and retrieve it, but not sure how to let the PicAXe know that the data is needed and when to send it. If you could point me to a post or two dealing with this it would be helpful.

Thanks, Bayside

 

[administrator]

This is exactly what the axe110 datalogger kit did. From the File menu select Open samples and look at the sample code for the axe110 kit for ideas.

https://picaxe.com/docs/axe110.pdf

 

[Bayside888]

Thanks for the reply. I only see two small programs to download the data. I don't see any code for the program to load on a 28X2 on a separate board, to actually acquire the data and look for a signal(s) to start the download. I can't use the 110 datalogger for this application. Has to be a custom board. Am I missing something?

 

[Flenser]

Baayside888, here is something to get you started with your project:
This thread posted about a PICAXE datalogger program Simplest Datalogger and the details of that project are on this web page Picaxe Simplest Datalogger

 

[bpowell]

I had built my own data logger a few years ago ... I had a push-button dedicated to starting a download ... so I'd plug my PC in to the PICAXE ... open the serial port ... press the "donwload" button, and I'd get a prompt like, "Press 'G" to go..." I'd make sure I was capturing the terminal screen, and I'd hit "G" ... all my measurements would pour out comma separated, and I'd just plop it all right into Excel.

 

[Bayside888]

Flenser and bpowell: thanks, for the advice --- looking at both right away.

bpowell: so, you had a routine in the PicAxe to poll the "download" button? Then access the serial port -- I had thought about that.

Flenser: you create the "Dump" command in your program...... I will take a good look at this.

Regards:

 

[Technical]

Am I missing something?

In the PICAXE Editor use the PICAXE>Wizards>AXE110 Datalogger wizard. This will generate the framework of a PICAXE program that can be easily modified as required.

Then the PICAXE>Datalink button can extract (and graph) the data at a later point.

 

[bpowell]

bpowell: so, you had a routine in the PicAxe to poll the "download" button? Then access the serial port -- I had thought about that.

Yeah ... the PICAXE would check to see if the button was pressed every pass through its loop ... if it WAS pressed, it would send out the serial port, "Hit G when ready to go" ... then, when I sent a "G" back, the PICAXE would start at address 0 on the EEPROM, read the byte, and send it out the serial port ... just a for-next loop to move through the eeprom and send it all out the serial port. I think I had it send a CR/LF on each new line ... so I wanted them separated that way for importing into Excel.