Configuring ERF with Wizards and Ciseco Explorer Plus

Circuit

Senior Member
I am probably missing something really obvious...but after a day of hair-pulling I am asking for help, please.
I am trying to configure an PICAXE ERF unit using the URF/SRF/XRF/ERF configuration wizard (v1.03) under PICAXE EDITOR 6.064.
I am using a Ciseco B009 Explorer Plus to interface the ERF to the Wizard. If I stick an XRF module into the 20 pin socket it responds perfectly to the Wizard; it is found and I can reconfigure it. When I patch in the PICAXE-original ERF unit into the same socket I get a unit not found message every time. Yes, I have tried the "Find Baud" option and this gets me nowhere. I attach a photo of the patch-leads; very straightforward; ground to ground and ERF CTS; + to +; ERF RX to socket RX and TX to socket TX.
What am I doing wrong?

erf-test.jpg
 

Technical

Technical Support
Staff member
What am I doing wrong?
Using a PICAXE ERF, which has inverted polarity, within a non-inverted setup.

You can configure the ERF via direct connection to i/o pins of any PICAXE chip - use the ERF specific wizard.
 

Circuit

Senior Member
Using a PICAXE ERF, which has inverted polarity, within a non-inverted setup.

You can configure the ERF via direct connection to i/o pins of any PICAXE chip - use the ERF specific wizard.
Wow! talk about fast service; many thanks.
OK, so the method that you suggest requires me to write a program, using I presume the ERF configuration wizard, and configure the ERF directly from the chip. Is there any way that the URF/SRF/XRF/ERF configuration wizard (v1.03) can be connected up to the PICAXE ERF unit? Or is the URF/SRF/XRF/ERF configuration wizard (v1.03) only there to address Ciseco original ERF units? I cannot locate any clear documentation regarding the wizard - is there any?
 

Technical

Technical Support
Staff member
Sure, you can use the wizard direct with the PICAXE ERF but you need inverted polarity from what you are currently using. Do you have an AXE027?
 

Circuit

Senior Member
Yes, I have several AXE027 - my most used cable! Do I just patch it directly to the ERF or do I need any intervening resistors? This is new territory for me, but potentially very useful indeed.
 

hippy

Technical Support
Staff member
I have always connected my AXE027 directly to the ERF module but for extra protection resistors could be added as shown on the RHS image.

Not sure of the best value to use but 220R to 1K should be appropriate. The LED+1K is optional.
 

Attachments

Circuit

Senior Member
First rate, thank you.

Implemented on stripboard this afternoon and working perfectly; precisely what I wanted as I have a number of ERFs to reconfigure.
I have attached the stripboard diagram and photos of the finished item for the benefit of others who may also have the same requirement.

PICAXE ERF programming adaptor.jpgERFTOPCTOPSIDE.jpg
 

Circuit

Senior Member
A couple of further images; one of the solder side and one of the unit with the ERF in place. I have attached the board directly to a 3xAA battery box with double-sided foam tape to make it quick to use. No switch needed as no power connections until the ERF is plugged in. I guess the AA cells will just about last forever! (or until they leak through age...)
ERFTOPCSOLDERSIDE.jpgERFTOPC.jpg
 

hippy

Technical Support
Staff member
That's an excellent programming board, and it looks like you used 330R resistors for current limiting. Glad to hear it's working okay.
 

Circuit

Senior Member
That's an excellent programming board, and it looks like you used 330R resistors for current limiting. Glad to hear it's working okay.
Thank you, Hippy; a simple but convenient board for the job but merely an embodiment of your circuit.

Yes, I somewhat arbitrarily chose the 330R for current limiting, but the more I think about it the more I wonder if they have any point at all? I don't really see a possible overcurrent situation with this circuit, but perhaps I am missing something?
I also checked out the Texas Instruments CC1110 datasheet for some guidance and again I can't really see an overcurrent situation arising with this arrangement; its not like we had PIC pins being swapped as input/output here. Also, I note that the datasheet specifies pull-up or pull-down resistance on any i/o pin should be 20K. I guess that it doesn't make much difference, but if I was building it again I would use a pull-down of 20K to be in line with the datasheet. Just thought I should mention it as you have 10K in your rather nicely-executed diagrams which look like they may be heading for a revised RevEd datasheet. Your thoughts?
 

hippy

Technical Support
Staff member
Yes, I somewhat arbitrarily chose the 330R for current limiting, but the more I think about it the more I wonder if they have any point at all? I don't really see a possible overcurrent situation with this circuit, but perhaps I am missing something?
There could be a potential for some sort of adverse connection while inserting the jack so it was more a defensive measure against that. Not sure if they are actually needed, but safer to have them than not!
 
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